3a. Fixing the CPU board.
Much of this information thanks to Leon. I've taken his info,
reworded it and added a bunch of comments and notes.
Initial CPU Checking.
There are a couple of things that should be noted right off
when trying to fix an original non-working Gottlieb System 1 CPU board.
First, is there any battery corrosion on the CPU board? If so, stop
now and fix this by going here. The
corrosion needs to be removed, neutralized, and any broken
traces and corroded parts repaired and/or replaced. This will
especially be an issue around the Z6,Z7 chips (to the right of the battery)
and Z8,Z28 chips (to the left of the battery). All bets
are off until a corroded CPU board is fixed. After any questionable
parts are replaced, be sure to use a DMM set to continuity and
check all the related board traces. Even one broken trace can definitely
make a CPU board not work.
Second, is there 4.95 to 5.2 volts DC at the CPU board? Best place to check
for this is at the C16 capacitor (top most cap next to the
the J1 power connector). Is there -12 volts DC at the CPU board?
Best place to check for this is at the C17 capacitor (right below
the C16 cap) next to the J1 power connector.
The machine will absolutely not boot without +5 and -12 volts.
Assuming the above voltages are correct, next check the score displays.
Do they come on right at power-on and "strobe"? If so, there is
a problem with the normally closed Slam switch. The CPU board should
be modified so the useless Slam switch is not an issue (see
here for details on that).
Last, do the score displays come on after the game is
powered on for 5 seconds? They should, as this is the normal
system1 boot sequence. If they don't, then the CPU board is
indeed "dead". If the CPU board turns on the score displays
after 5 seconds of power, that is a good sign that the board
is at least trying to boot.
Also set the CPU board DIP switch as follows:
- DIP 1-8=off (one coin, one credit).
- DIP 9=on (three balls per game).
- DIP 10=on (match feature on).
- DIP 11=on (replay instead of extra ball).
- DIP 12=on (tilt kills current ball only).
- DIP 13=on (show number of credits).
- DIP 14=on (play a tune when game started).
- DIP 17,18=on (maximum credits 15).
- DIP 20=on (chimes/tones when scoring).
- DIP 21=on (show high score to date).
- DIP 22=on (award 3 credits when high score beat).
- DIP 23=on (play a tune when money inserted).
Having the switches in these positions will
make troubleshooting a bit easier and consistent from board to board.
Adding +5v and -12v Power LEDs to the CPU board.
Though this modification certainly doesn't fix a dead CPU board,
I personally find it nice to have LEDs showing that +5 volts and -12 volts
is at the CPU board. Using two LEDs and 150 ohm and 560 ohm resistors,
it's easy to add a couple LEDs to the CPU board next to the main power
connector. You will have to drill a pair of 1/16" holes for each LED,
but there's plenty of room to do this by the power connector. The +5 volt
LED needs the 150 ohm resistor as a load, and the -12 volts needs the 560 ohm
resistor. Note the resistors can be mounted on either the power or ground
side of the LED. It is important to connect the flat side of the LED correctly
or the LED won't work. (See the two pictures below.)
Adding two power LEDs to the CPU board for +5 and -12 volts.
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The back side of the CPU board where the LEDs are connected to +5 and -12 volts.
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Booting the CPU board on the Workbench.
At this point, it's a lot easier to diagnose and fix the
CPU on the workbench (instead of in the game). The best
way to do this is using a computer power supply. The only
voltages needed to boot the CPU board are +5 and -12 volts DC.
So any computer power supply that outputs these voltages
should work fine. Connect the computer power supply to
the J1 (left side) CPU power connector:
- A1J1 pin 1 (bottom most pin): not used.
- A1J1 pin 2: -12 volts DC.
- A1J1 pin 3: ground
- A1J1 pin 4: ground
- A1J1 pin 5: +5 volts DC.
- A1J1 pin 6 (top most pin): +5 volts DC.
Another perhaps easier way to connect the voltage from the
computer power supply to the CPU board is using the C16 (top most)
and C17 (below C16) capacitors next to the J1 power connector:
- C16 top cap, top lead: +5 volts DC
- C16 bottom lead: ground
- C17 bottom cap, bottom lead: -12 volts DC
Installing an "Alive" LED.
Now the next problem to overcome are the score displays, or
the lack of score displays. Since we can't use score displays
on the workbench, we need some way to tell if the CPU board
is "booting". When mounted in a game this is easy, as we turn
the power on, wait 5 seconds, and then the score display should
turn on (indicating a proper boot sequence). Yet on the workbench we can't do this.
Instead we use an LED and a resistor connected to chip Z16 pin 15 (upper right
most chip on the CPU board). Just a water clear style LED (that's important that
it's a water clear style) and connect the flat side to a 150 ohm resistor. Connect
the other side of the resistor to ground (Z16 pin 8.) Now connect the non-flat side
of the LED to Z16 pin 15. When the CPU board is powered-on, after a 5 second delay, the LED should
light up (just like a miniature score display). If we can get our
CPU board to light this LED after a 5 second delay, this is our indication that
the CPU board is "running". Since the CPU board is in attract mode, the LED will
dim when the game switches shows the high score to date in all the score displays.
Likewise the LED will be brighter when just the last game played ("000000") shows
in just the player1 score display.
So if you have gotten this far, and the board is booting, you can skip down to the
Testing the Buffer and Spider Chips. Otherwise keep reading...
Alive LED: Connect a 150 ohm resistor to chip Z16 pin8 (gnd), with the
other side of the resistor going to the flat side of an LED. Then attach
the non-flat side of the LED to Z16 pin15. Adding this LED gives the CPU board
an "alive" LED, which lights when the score displays turn on, indicating a
booting CPU board.
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Here's a different way to install the "alive" CPU board LED. This LED
is mounted with two drilled 1/16" holes, and the 150 ohm resistor going
to z16 pin15 and ground on the back of the CPU board.
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Note on some games I have added the "alive LED",
and I have the CPU working and installed in an actually pinball machine,
there was one segment on the score displays that did not work.
This one segment would be on player1, player2, and the
credit display. This only happens on some machines, and
I'm not entirely sure why. I've used the "alive LED" on a great
many CPU boards, yet once installed in some games, I have this
one display segment missing issue. The solution is to just remove
(or disable) the "alive" LED once you have the CPU board
working in your game.
Dead CPU: Next Steps.
The CPU board is completely dead, with no score display
activity after 5 seconds of power-on.
Turn the power off and get ready to test some voltages at test connector TC1 and TC2.
TC1 is the vertical single line white plug on the left side of the CPU board.
TC2 is the vertical white plug in the dead center of the CPU board.
On both TC1 and TC2 pin1 is the top most pin.
Reset Circuit:
The reset circuit holds the CPU chip low for a set period of time until
the +5 volts can stablize. If the CPU chip is never told to go "high" from
the reset circuit, the board will never start to boot.
Measure TC1 pin 14 (or chip Z2 pins 7,9) and power the CPU on. It should show immediately at
power on -12 volts. This will rapidly change into +5 volts after about
half a second. This is the RESET signal.
Another place to check the Reset is at chip Z2 pins 7,9. (Both should go high to 5 volts after about one second of power-on.)
If the reset is not working and does not change to +5 volts,
it is best to replace the Q5 and Q6 (MPS-A70) in the reset circuitry.
If the reset is still not going from -12 to +5 volts, change chip Z2 (4528 CMOS.)
Still not working, check or replace caps C31 and C32 (.1 mfd, and these
do sometimes fail).
Note that the "Reset" button on the CPU board has
nothing to do with this Reset signal (it is only used to reset bookkeeping
values).
Reset components on the CPU board.
From actual Gottlieb documents, so it's their property.
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Gottlieb revised the RESET circuitry during System1 production.
The new version gives a longer Reset and ensures the CMOS RAM
is locked out quickly at power-off. Older boards can be upgraded
if desired.
- R159 Change 2.7meg to 3.9meg ohms
- R160 Remove.
- R161 Change 27k to 43k ohms
- R162 Change 6.8k to 2k ohms
- R163 Change 27k to 6.8k ohms
Clock Circuit.
The next thing we check are the clock signals. The clock circuit
provides the timing the CPU chip needs to execute. This is provided
by the CPU board crystal and the U1 spider chip.
Check TC2 pins 11,12
using an oscilloscope or a logical probe, and there should be pulsing
signals. Also check both legs of the crystal, and the same
pulsing should be seen on both legs.
If an o'scope is not available, use a DMM set to DC volts.
This should show 2.8 volts at TC2 pin11 and 2.9 volts at TC2 pin12.
The top leg of the crystal should show .3 volts, and the bottom
leg should show .9 volts.
If there are no clock pulses, there is a problem with the Rockwell
U1 spider chip, and the story ends here (as the spider chips are
no longer available). The only choice is to buy a new NiWumpf or Pascal CPU
board. There is a chance the crystal (above the J1 power connector)
is bad, but that is unlikely (but it does happen). Crystal Y1 is a 3.579 MHz crystal.
Address/Data Line Activity. Now that we have a reset and clock circuit,
check the address and data lines for activity. This is done at TC1 pins 1-13.
Use an o'scope or logic probe looking for pulsing lines.
If there's no pulsing, the Rockwell spider chip(s) are bad,
and again the story ends here (buy a NiWumpf or Pascal CPU board). If
pulsing is seen at TC1 pins 1-13, then it's time to move to the next step.
Score display LED On?
At this point the CPU board should be booting on the bench.
This can be seen by viewing the LED we added to simulate the
score displays coming on. With the Slam switch defeated,
there should be a 5 second delay after power-on, and then
the added LED should light. If this is the case, we can now
move to testing the Spider chips and Buffer chips. If this
LED is not coming on, and all the above tests check out good,
it's time to buy a NiWumpf or Pascal CPU board.
Testing the Input/Output Buffer and Spider Chips.
In order to check the buffer chips, we will activate
the buffer inputs, and see if there is a corresponding response at the
buffer outputs.
The buffers chips are Z29 (7405) and Z27 (74H21), both right below
the DIP switch. Also Z9 (7405) and Z8 (7404), both at the bottom left
of the CPU board. Use an alligator clip
connected to ground to activate the buffer inputs,
which will control the buffer output pins. A logic probe is best
for checking the output, but a DMM set to DC volts can be used.
Ground Z29 pin 1 (input) and check pin 2 (output).
Ground Z29 pin 5 (input) and check pin 6 (output).
Ground Z29 pin 11 (input) and check pin 10 (output).
Ground Z29 pin 9 (input) and check pin 8 (output).
All outputs should show +5 volts.
Ground Z27 pin 1 (input) and check pin 2 (output).
Ground Z27 pin 3 (input) and check pin 4 (output).
Ground Z27 pin 5 (input) and check pin 6 (output).
Ground Z27 pin 9 (input) and check pin 8 (output).
Ground Z27 pin 11 (input) and check pin 10 (output).
Ground Z27 pin 13 (input) and check pin 12 (output).
All outputs should show +5 volts.
Switch Matrix Returns:
Ground Z9 pin 1 (input) and check pin 2 (output).
Ground Z9 pin 3 (input) and check pin 4 (output).
Ground Z9 pin 5 (input) and check pin 6 (output).
Ground Z9 pin 9 (input) and check pin 8 (output).
Ground Z9 pin 11 (input) and check pin 10 (output).
Ground Z9 pin 13 (input) and check pin 12 (output).
All outputs should show +5 volts.
Switch Matrix Returns:
Ground Z28 pin 3 (input) and check pin 4 (output).
Ground Z28 pin 11 (input) and check pin 10 (output).
All outputs should show +5 volts.
If any input is grounded and it's associate output does not
respond (by going to +5 volts), the chip is bad.
Switch Matrix Strobe. Best to use a logic probe for this:
Z8 pin 1/2 = Strobe0: both pins pulsing.
Z8 pin 3/4 = Strobe1: both pins pulsing.
Z8 pin 5/6 = Strobe2: both pins pulsing.
Z8 pin 9/8 = Strobe3: both pins pulsing.
Z8 pin 11/10 = Strobe4: both pins pulsing.
Z8 pin 13/12 = Strobe5: both pins pulsing (not used in any system1 games).
If the logic probe shows pulsing just on the input side of the Z8 7404 (first
pin listed above) and not on the output pin, then the 7404 chip at Z8 is bad.
If incorrect activity (no pulsing) is seen on the input side
of the Z8 7404 chip, then the U5 spider chip is bad, and the story ends here.
Now we can test the solenoid buffer chips at Z6 and Z7 (7417).
The 7417 chips at Z6 (located just above connector J5)
and Z7 (to the right of Z6). The U4 spider chip sends signals to the
Z6/Z7 buffers, which then signal the
driver board transistors at Q25-Q32 for the CPU controlled coils.
With the CPU board power on,
attach an alligator clip to +5 volts (the positive/upper lead
of capacitor C16 on the CPU board). Then touch the Z6 input pins
(one at a time) with +5 volts, and watch the output pin:
So once the solenoid buffer chips are tested, we
need to have some way to test the U4 spider chip
(which sends solenoid signals to Z6/Z7).
It is impossible to control all the outputs of U4 on the bench,
but if we control some of them. If the U4 works for
the ones we can control, it will probably be OK for the rest.
We can use the machine's "play-a-tune" feature when
a coin switch is activated (make sure DIP switch 23 is "on").
If we can simulate a coin switch closure,
the U4 spider chip will send signals to the Z6 chip,
activating the three chime coils (or sound board triggers).
We can see this with a logic probe at the Z6 chip.
To simulate a coin switch closure,
Use a jumper wire and connect one end to chip Z8 pin 4.
With the other end momentarily touch Z9 pin 1. This
simulates a coin drop by momentarily touching switch matrix
strobe1 to return0. Using a logic probe, check the following
Z6 solenoid buffer chip pins which the U4 spider chip toggles:
Z6 pin 5 (ten point chime).
Z6 pin 9 (hundred point chime).
Z6 pin 11 (thousand point chime).
You should see the above pins go high as the coin switch closure
is simulated. If any one of the above pins do not go high, the U4
spider chip is bad. Since there is no replacement available for
the U4, the CPU board is junk and must be replaced.
The only thing not tested on the bench is the U6 spider chip
and Z16/Z17 7448 chips that control the score displays. This spider rarely fails,
and it is very easy to test the displays using the game's
built-in diagnostics. So there really is no need to do this
on the workbench.
CPU Considerations (Spider chips, etc).
The Rockwell PPS-4/1 and PSS-4/2 system was a 4-bit parallel processing system
with two CPU "spider" chips that communicate with each other
(U1 11660-CF was the main processor, and U2 10696-EE was the second processor).
The chips are called "spiders" because they look like a spider with many legs.
The spider chips were a wider chip package, almost a square chip.
System 1 used six of these custom spider chips labeled U1 to U6: two for the CPU (U1/U2) and
one each for the switch matrix (U5 A1752-CF), solenoid control (U4 A1753-CE), and score
displays (U6 10788-PA). The
last spider chip (U3, also a 10696-EE chip, same as the second CPU processor at U2) was used for
lamps and a few switches and left over duties.
Both the switch matrix (U5, A1752-CF) and solenoid control (U4, A1753-CE) spider chips
have built-in ROM software. Display output was controlled by the
U6 spider chip (10788-PA). The switch matrix has eight rows (R0-R7) and five
columns (S0-S4), for a total of 40 switches. These are all driven by
chips Z8 (strobes/columns, 7404) and Z9/Z28 (rows, 7405).
Two System 1 CPU board spider chips and the game PROM ("C" means Joker Poker).
The added red wire to cap C16 negative lead is part of the ground modifications.
Note the two "spider chips" shown in this picture.
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The solenoid control (U4, A1753-CE) and switch matrix (U5, A1752-CF) spider chips are notorious for
failing easily. The solenoid control spider dies from locked on coils due to
driver transistor failure. The switch matrix spider dies from coil voltage
being shorted to the switch matrix.
The two CPU spiders (U1 11660-CF and U2 10696-EE), the display spider (U6, 10788-PA) and
the U3 (10696-EE) spider rarely fail. Unfortunately none of the
spider chips are available, hence replacement
CPU board have been created by Ni-Wumpf and Pascal Janin).
Here's a summary of the spider chips:
- U1, 11660-CF (CPU)
- U2, 10696-EE (CPU)
- U3, 10696-EE (misc lamps and switches). Same as U2 spider
- U4, A1753-CC,CE,EE (solenoids, often fails)*
- U5, A1752-CD,CF,EF (switch matrix, often fails)*
- U6, 10788-PA (display)
* Note that spider chips U4 or U5 contain the game operating system ROM,
and must be of the same revision. These are the two spiders that fail
the most. The revision levels that work together are:
- U4 A1753-CC works with U5 A1752-CD
- U4 A1753-CE works with U5 A1752-CF
- U4 A1753-EE works with U5 A1752-EF
Socketing Spider Chips.
If you are lucky enough to find NOS (new old stock) spider chips
(or have boards to steal them from), these old spiders need to be
removed and the new spider installed. Removing these is standard
desoldering. But a new CPU spider chip should probably be socketed
on the CPU board.
To do this, buy some SIP (single inline pin) machine pin sockets,
and solder them into the board. This way the spider can be pluged
into the SIP sockets. As a note of caution, it's best to "double up"
the SIP sockets (as shown in the picture below). This is done for
two reasons. First so the spider legs (which are somewhat wide) don't stretch the SIPs
soldered into the board. That is, if the spider legs cause problems,
they will ruin the easy-to-remove SIPs on the legs, not the SIPs
soldered into the CPU board.
The second reason to "double up" the SIPs is to aid in the
installation of the spider chip into the board-mounted SIPs. Aligning
all the spider chip pins is tricky. But if extra SIPs are installed on the
spider chip first, installation of the spider chip into the board-mounted
SIPs is *much* easier.
A socketed Spider chip on a CPU board. Note the use of "doubled up" SIP sockets.
Picture by Scott.
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3b. Game ROMs, PROMs, EPROMs and Test PROM.
The game PROM at Z23 is a 18 pin PROM which contains the game specific
rule computer code for the CPU board. This bipolar PROM is not duplicatable in its
native form, as blank PROMs are long gone. Also nearly
long gone is any sort of PROM programmer that would program a blank (if
one could be found). Add to this that the bipolar PROM at Z23 is often
bad (it runs very hot, even when working properly), and this becomes
a problem for a System1 CPU board.
Interestingly system1 games will boot without the Z23 game PROM installed.
Because the majority of the system code is inside the "spider" chips,
the game PROM is not needed to boot a system1 CPU board. Diagnostics/audit
can even be run with no Z23 game PROM installed. The game can be coined up.
But if a game is started with no Z23 Game PROM installed, the start-up sounds
will play, and then the game will lock up.
Using a 2716 EPROM for the Game PROM at Z23.
A 24 pin 2716 EPROM can be used instead of the 18 pin
bipolar PROM at Z23. But to do this a couple things are needed.
First an adaptor board must be purchased or made. Pascal Janin sells
an adaptor board. Next the
Gottlieb system1 PROM images must be formatted for a 2716 EPROM
(available here in a ZIP file - updated 10/20/06
as the Buck Rogers code was bad).
Ni-wumph's main game 27256 EPROM and board manual is available directly from
Niwumpf's support web page.
The Niwumph EPROM image is also available
here and the manual
here for convenience.
Schematics for Niwumpf are also available
here,
here,
here.
Making a 2716 EPROM Adaptor for the Game PROM at Z23.
The original Gottlieb System1 Game PROM is a bipolor PROM with a
1024 x 4 bits size. These are no longer available in programmed or
blank format. Even more rare is the type of hardware that does
the programming for these obsolete bipolar PROMs.
A system1 PROM to 2716 EPROM adaptor board layout (from
Leon Website).
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System1 Game PROM to 2716 EPROM adaptor boards.
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To get around this problem, the Pascal Janin and PinLizard used to sell an
adaptor that allowed for a 24 pin 2716 EPROM to plug into the smaller
18 pin bipolar PROM socket on the CPU board. Unfortunately the PinLizard version
is no longer sold (but the Pascal Janin version is still available.)
You can also make your own adaptor using the cross information below.
It just requires the data/address lines to be crossed from
one socket type to the other, and an added .1 mfd capacitor between
+5 volts and ground.
- PROM pin 1 to EPROM pin 22
- PROM pin 2 to EPROM pin 2
- PROM pin 3 to EPROM pin 3
- PROM pin 4 to EPROM pin 4
- PROM pin 5 to EPROM pin 5
- PROM pin 6 to EPROM pin 8
- PROM pin 7 to EPROM pin 7
- PROM pin 8 to EPROM pin 6
- PROM pin 9 to EPROM pin 12,18,19,20 (ground)
- PROM pin 10 to EPROM pin 13
- PROM pin 11 to EPROM pin 11
- PROM pin 12 to EPROM pin 10
- PROM pin 13 to EPROM pin 9
- PROM pin 14 to EPROM pin 12,18,19,20 (ground)
- PROM pin 15 to EPROM pin 23
- PROM pin 16 to EPROM pin 1
- PROM pin 17 no connect
- PROM pin 18 to EPROM pin 21,24 (+5 volts)
Gottlieb System1 Test PROM "T".
Because the internal diagnostics are somewhat limited for
System1 games, Gottlieb also made a "T" bipolar Test PROM.
These are very difficult (if not impossible) to find. But if
you have a 2716 EPROM adaptor, you can download the
Test PROM
code in 2716 format and use the adaptor board.
Using the System1 Test PROM.
The Test PROM boots just like any other System1 game (this is because
the boot code is actually in the spider chips, not in the Game PROM).
The game will seemingly be in "attract mode" too with the "T" PROM installed.
Pressing the Test button inside the coin door will yield the same
audit/tests just like a game PROM was installed (or nothing was installed)
at Z23. The tests are no different. Again this is because the audit/test
code resides in the spider chips and not the Game PROM.
To access the Test PROM start a game (no credits are needed, but
you can add credits if you want, and the coin-up tune will play).
As soon as a game is started the game start-up sounds will play (10,100,1000 point
sounds or chimes coils 3,4,5) and then the outhole (coil1), the knocker (coil2), the outhole (again),
and three game specific coils 6,7,8. While this is happening the Game Over relay will
pull in for about two seconds and then release. All the coil energizing happens
very fast at game start (the only coil that does not pull in is the
Tilt relay). Also all 36 of the CPU controlled lights
will turn on for about two seconds and then turn off.
The CPU lights do this (starting with lamp #01 to
lamp #36) in a quick progression.
At this point the game's playfield switches becomes the Test PROM's
input. All game switches (except for the two coin chute and credit button)
have a test function. All the CPU controlled lamps should be off.
Hitting a playfield switch should toggle a CPU controlled lamp on or off,
and/or fire a solenoid. If the game has all 40 switches wired, all 36 CPU
controlled lamps can be turned on (assuming the game uses all 36 lamps).
You will need the game manual to know how a playfield is wired
for this exercise, because you will need to know where each
switch number is found on the playfield to determine what it controls.
The slam switch or outhole switch will exit the "game" (test) mode and
go back to attract mode.
| Switch# |
Action |
Score Display |
| Sw #00 (test button) |
Lamp #01 (Game Over) |
Pulls in Game Over relay and switches to audit/diag mode. |
| Sw #01 |
Coin Chute 1 |
|
| Sw #02 |
Coin Chute 2 |
|
| Sw #03 |
Credit button |
Start Test/Add a player |
| Sw #04 (tilt) |
Lamp #02 (tilt)
Pulls in Tilt relay quickly |
Can end the "game" (test) mode. |
| |
| Sw #10 |
Coil 2 (knocker)
Toggles Game Over relay/lamp |
|
| Sw #20 |
Coil 3 (10 pts)
Toggles lamp Q3 (high score) |
|
| Sw #30 |
Coil 4 (100 pts)
Toggles lamp Q4 (shoot again) |
|
| Sw #40 |
Coil 5 (1000 pts)
Toggles lamp Q5 |
|
| Sw #50 |
Coil 6
Toggles lamp Q6 |
|
| Sw #60 |
Coil 7
Toggles lamp Q7 |
|
| Sw #70 |
Coil 8
Toggles lamp Q8 |
|
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| Sw #11 |
Toggles lamp L9 |
Scores 10 by 1s when L9 lites |
| Sw #12 |
Toggles lamp L16 |
|
| Sw #13 |
Toggles lamp L23 |
|
| Sw #14 |
Toggles lamp L30 |
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| Sw #21 |
Toggles lamp L10 |
Scores 90 by 10s when L10 lites |
| Sw #22 |
Toggles lamp L17 |
|
| Sw #23 |
Toggles lamp L24 |
|
| Sw #24 |
Toggles lamp L31 |
|
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| Sw #31 |
Toggles lamp L11 |
Scores 900 by 100s when L11 lites |
| Sw #32 |
Toggles lamp L18 |
|
| Sw #33 |
Toggles lamp L25 |
|
| Sw #34 |
Toggles lamp L32 |
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| Sw #41 |
Toggles lamp L12 |
Scores 9000 by 1000s when L12 lites |
| Sw #42 |
Toggles lamp L19 |
|
| Sw #43 |
Toggles lamp L26 |
|
| Sw #44 |
Toggles lamp L33 |
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| Sw #51 |
Toggles lamp L13 |
Scores 90,000 by 10,000s when L13 lites |
| Sw #52 |
Toggles lamp L20 |
|
| Sw #53 |
Toggles lamp L27 |
|
| Sw #54 |
Toggles lamp L34 |
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| Sw #61 |
Toggles lamp L14 |
Scores 900,000 by 100,000s when L14 lites |
| Sw #62 |
Toggles lamp L21 |
|
| Sw #63 |
Toggles lamp L28 |
|
| Sw #64 |
Toggles lamp L35 |
|
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| Sw #71 |
Toggles lamp L15 |
|
| Sw #72 |
Toggles lamp L22 |
|
| Sw #73 |
Toggles lamp L29 |
|
| Sw #74 |
Toggles lamp L36 |
|
3c. Built-in Diagnostics/Bookkeeping
Inside the coin door there is a large white momentary switch
that is known as the "play/test" button. Press this button
to access the game audits and test modes. After the button
is pressed, it takes about one second and then the audit number
"0" will appear in the ball/credit display, signifying the first
audit value. The value for the audit
will appear in the score displays. As the test button is pressed,
the ball/credit display will increment
a number 0 to 13 indicating the test/audit number.
If any audit number (0-10) needs to be cleared, press the CPU board mounted
black "reset" button to clear the audit value.
To exit the test mode, either open the Slam switch or close
a Tilt switch.
Note on the high score level replay values.
Setting a "zero" at high score level means the level is not in use.
But this does not apply to the High Game to Date score level
(the zero does not disable this).
While in audit/diagnostic mode, the Q (game over) relay will be
energized. This means the flippers and pop bumpers and slingshots (non-CPU controlled)
coils should work while the game is in audits.
The Gottlieb System1 coin door with the diagnostic entry switch.
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|
Here are the audit/test numbers and what they represent:
Audits:
- Total coins thru coin chute #1.
- Total coins thru coin chute #2.
- Total plays.
- Total replays given.
- Number of slam tilts.
- Number of extra balls.
- Number of tilts.
- First replay score value.
- Second replay score value.
- Third replay score value.
- Current High Score to date.
Diagnostics:
- Display test for player #1 and #3 score displays. Increment display
values from "000000" to "999999" in player1 and player3 score displays.
- Display test for player #2 and #4 score displays. Note the credit
display is *not* tested in either test #10 or #11.
- Lamp/Coil/Switch test: see below for description.
Diagnostics.
After advancing through all the audits (0-10) and the display
tests (11/12), diagnostic #13 will engage. After a second,
all CPU controlled lights come on for
five seconds. That's not much time to find a CPU controlled
light that is burnt out! But unfortunately there's no way
to keep the #13 diagnostic in lamp mode for any longer than
five seconds. And to re-engage the lamp mode will require
exiting diagnostics (or power cycling the game), going thru
all audit/tests 0 to 12, and then advancing to test #13
(for another five seconds of turned on lamps). This does not
make for easy lamp testing.
Another problem with the lamp test is lamps L3 and L4 (Q3 and Q4).
On many System1 games, these two MPS-U45 transistors are used for
the High Score to Date and Shoot Again lamps. Hence these two
lamps (L3/L4) are tested in the lamp test (on for five seconds
upon entering test #13). But on some System1 games Q3 and Q4 are
used as pre-drivers to under-the-playfield mounted 2N5875 transistors.
These in turn control a playfield solenoid. If this is the case,
these two solenoids will energize for five seconds in the lamp test!
Just keep that in mind.
After the CPU controlled lamps are turned off,
each CPU controlled solenoid is energized one at a time.
Well not really all of the CPU controlled solenoids. For
example, the T (Tilt) relay is not included in this test.
Neither is the Q (Game Over) relay, which is already energized
during the whole audit/test routine. But all the other ten
solenoids (including three sounds/chimes) will be tested ONCE.
Then the test moves to the switch matrix test. If there are no
closed switches, after about 5 seconds the game will exit test #13 and
go back to attract mode. If a closed switch is found, it will display
in the ball/credit display. If you want to test a switch, do it now!
Hurry up though. If no other switches are sensed as closed within a
five second window, the game will exit the test mode and go back
to attract mode. Also if you hold a switch closed, it takes about
*two* seconds before that switch number appears in the ball/credit
display! Talk about a slow CPU board.
Overall the #11,#12,#13 Gottlieb System1 diagnostic tests are pretty lame.
Especially compared to comparible Bally and Williams diagnostics
of this era (1977-1980). Ideally it would be nice to flash all
the CPU controlled playfield light on and off continually until
the user wants to proceed. This cannot be done with the System1
diagnostics. Also again it would be nice to keep running the
coil test over and over, and to keep the game in switch test mode
until the user wants to exit. Unfortunately these things can't
be done with the stock System1 diagnostics. This makes finding
bad CPU controlled lamps, coils, and playfield switches more difficult.
Another method of testing lamps, coils and score displays is to use a NiWumpf
CPU board. The testing routines in the NiWumpf board are *much*
better than the stock Gottlieb System1 tests. For example,
CPU lights can be continually cycled on and off. Same thing
with coils (and the Game Over and Tilt relays are activated too!)
And the NiWumpf display test also tests the 4-digit ball/credit display
(which the stock Gottlieb test does not).
So using the NiWumpf to test a driver board works very well.
The NiWumpf switch test operates as it should and is very quick to
display a closed switch (but unfortunately this test cannot
be used on a stock Gottlieb CPU board).
The Z23 Game PROM and Diagnostics.
Interestingly, a Gottlieb System1 CPU board does *not* need
the game PROM at Z23 to run diagnostics! Because
a lot of the system code for all system1 games is inside the
"spider" chips, the game PROM is not needed to run diagnostics.
The CPU board will boot up fine without the Z23 PROM. Heck
you can even try and start a game (the chimes will sound,
but then the game will lock up). So if you need to test a
System1 CPU board and don't have a Z23 game PROM, no problem.
Just boot the game and press the coin door diagnostic test
switch. It will go through the audits and diagnostics
whether the Z23 PROM is installed or not.
Gottlieb Test PROM for Z23.
Gottlieb also made its own Test PROM that installs at Z23
instead of the game PROM. This provides much
better testing of a stock Gottlieb System1 CPU board.
Unfortunately the original 6351 PROM is not readily available.
3d. Locked-on or Not Working Coils
The driver board is largely responsible for controlling coils and lamps.
Of course signals for this start at the CPU board, but ultimately if a coil
does not work correctly, the driver board is a good starting point.
Remember there's two different kinds of coils on a system1 game: CPU controlled
and non-controlled. You'll need to know which type you're working with to
further diagnose any coil problems. We'll be concentrating on the CPU controlled
type of coils, as those are more difficult to diagnose and fix.
CPU controlled versus non-CPU controlled coils.
|
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Diagnosing Coil Problems.
Step 0: Coil CPU or Non-CPU Controlled?
In the case of a non-working or locked-on coil, first figure
out if the coil is CPU controlled. Pop bumpers, slingshots,
coin door lockout and flipper coils are *not* CPU controlled. All other
coils are controlled by the CPU.
Next figure out which driver board transistor(s) control the
coil in question. Remember there are system1 "dedicated" coils, which are
the same for all system1 games. This includes the sound drives, knocker,
and outhole. The remaining three driver transistors are game dependant.
Add to that the possibility of two more under the playfield driver transistors
(driven by a small driver board transistor like Q17/Q18), and there are a total of
five possible game dependant CPU controlled coils (aside from the dedicated coils.)
Driver Board Transistor Overview
| Coil# |
Description |
Transitor# |
Notes |
| 1 |
Outhole |
Q32 (2n6043) |
Dedicated |
| 2 |
Knocker |
Q25 (2n6043) |
Dedicated |
| 3 |
10pt Chime |
Q26 (2n6043) |
Dedicated |
| 4 |
100pt Chime |
Q27 (2n6043) |
Dedicated |
| 5 |
1000pt Chime |
Q28 (2n6043) |
Dedicated |
| 6 |
Game dependant |
Q31 (2n6043) |
|
| 7 |
Game dependant |
Q30 (2n6043) |
|
| 8 |
Game dependant |
Q29, Q45
(mps-u45,
2n3055) |
|
Driver Board Transistor Detail
| Trans# |
Position |
Type |
Pre-driver |
CPU Chip |
Usage |
| Q25 |
Far right |
2N6043 |
|
CPU Z6 pin 3/4
to A1J5 pin 11 |
Knocker |
| Q26 |
2nd from rt. |
2N6043 |
|
CPU Z6 pin 5/6
to A1J5 pin 10 |
10 Chime or Sound |
| Q27 |
3rd from rt. |
2N6043 |
|
CPU Z6 pin 9/8
to A1J5 pin 7 |
100 Chime or Sound |
| Q28 |
4th from rt. |
2N6043 |
|
CPU Z6 pin 11/10
to A1J5 pin 8 |
1000 Chime or Sound |
| |
| Q32
| Center Left |
2N6043 |
|
CPU Z6 pin 1/2
to A1J5 pin 12 |
Outhole |
| Q31 |
2nd from Cnt Lft. |
2N6043 |
|
CPU Z6 pin 13/12
to A1J5 pin 9 |
Solenoid #6 (game specific)
Pre-driver for under PF trans |
| Q30 |
3rd from Cnt Lft. |
2N6043
|
| CPU Z7 pin 1/2
to A1J5 pin 1
| Solenoid #7 (game specific)
Pre-driver for Under PF trans |
Q29
Q45
| 4th from Cnt Lft.
Center Right |
MPS-U45
2N3055
| Q29
| CPU Z7 pin 3/4
to A1J5 pin 2
| Solenoid #8 (game specific,
usually for a drop target reset coil.)
|
| |
| Q2
| Far Left |
MPS-U45
|
| CPU LD2, Z26 pin 3/4
to A1J5 pin 5
to SDB Z1 pin 5/7
| Tilt (T) Relay
|
| Q1
| 2nd from Far Left |
MPS-U45
|
| CPU LD1, Z26 pin 1/2
to A1J5 pin 6
to SDB Z1 pin 4/2
| Game Over (Q) Relay |
| Q3 (L3)
| 3rd from Far Left |
MPS-U45
|
| CPU LD3, Z26 pin 5/6
to A1J5 pin 4
to SDB Z1 pin 12/10
| used for CPU controlled lighting
(L3=High Game to Date). |
| Q4 (L4)
| 4th from Far Left |
MPS-U45
|
| CPU LD4, Z26 pin 9/8
to A1J5 pin 3
to SDB Z1 pin 13/15
| Used for CPU controlled lighting
(L4=Shoot Again). |
| Q17 (L17)
| 14th from Far Left |
MPS-A13
|
| CPU LD1, Z26 pin 1/2
to A1J5 pin 6
to SDB Z5 pin 4/2
| Pre-driver for under PF trans, as needed |
| Q18 (L18)
| 13th from Far Left |
MPS-A13
|
| CPU LD2 Z26 pin 3/4
to A1J5 pin 5
to SDB Z5 pin 4/2
| Pre-driver for under PF trans, as needed |
| |
Q5-Q24,
Q33-Q44 |
Top middle row |
MPS-A13
|
| Z1-Z9
| Used for CPU controlled lighting. |
| |
| none |
under playfield |
2N5875*
| 2n6043 (Q30,31) or
MPS-A13 (Q17,Q18) |
Z1 SDB
| Playfield mounted Transistor(s)
(game specific) |
| |
| none |
|
|
|
|
Coin door lockout coil
connected directly to 25 volts. |
* Buck Rogers used a TIP115 under the playfield.
The Gottlieb System 1 driver board transistor layout.
From actual Gottlieb documents, so it's their property.
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The Gottlieb System 1 driver board transistor layout.
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Step1: Check for -12 volts at the CPU board.
If many or all solenoids and CPU controlled lamps are constantly on or solenoids do not
work at all, the problem could be missing -12 volts DC at CPU
board. Of course without this voltage the game won't "boot" either.
But check for -12 volts across CPU board cap C17 (below C16). If it is OK, the
problem could be in the CPU board buffers Z6 and Z7 (7417) too (more on
that later). When diagnosing a non-working game, it's best to removed
the card edge connector going between the CPU and driver boards. This
will ensure that no coils engage while you figure out why the game doesn't boot.
Step 2: Check the Coil Resistance.
This is very important. If a coil has a bad coil diode and/or
low resistance, any work done to the circuit boards will be
ruined when the game is turned back on (if it's a non-CPU controlled
coil, the solenoid fuse will immediately blow if the coil
is activiated). If any coil measures
below 2.5 ohms, replace it. See the
Checking Coil Resistance section for
more details.
Step 3: Check the Driver board to Coil Wiring (Connectors).
This only applies to CPU controlled coils.
With the game on and in game mode, use a DMM set to DC volts
and check for power at both lugs of the coil in question.
Power at only one lug means the coil is open (replace coil
or re-attach broken winding). Power at neither lug suspect a
bad solenoid fuse or the power "daisy chain" is broken up-stream.
Now move up to the backbox, and attach one end of an alligator clip
jumper wire to ground. Touch the other end of the jumper wire momentarily
to the metal tab of the controlling transistor. This should fire
the coil. (Note on Q29/Q45 controlling transistor pair, ground
only the metal tab of the larger Q45, as grounding the small Q29 will
yield nothing). If the coil does not fire,
suspect a bad connector on the bottom edge of the driver board
(or a broken trace on the driver board).
If the coil fires, time to move to the next step and test
the transistors and controlling chips, eventually moving all the
way back to the CPU board.
Connectors are a huge problem on System1 games, don't overlook them.
The connectors along the bottom edge of the driver board *and* the
connector that runs between the driver board and/or CPU board could
cause a coil to not work. See the Connector section
for more information on how to replace System1 connectors.
Step 4: Verify if an Under the Playfield Transistor is used.
Some later system1 games used one or two of the 36 driver board lamp transistors
to control additional playfield solenoids. The low-voltage (6 volt) lamp
transistors were wired to under-the-playfield mounted 2n5875 power transistors,
which drove a hi-power 24 volt solenoid. Essentially the lamp driver
transistor was a pre-driver for the larger playfield-mounted transistor, which
ultimately drove a coil. These playfield mounted transistors added another
level of complexity to the System1 design, and often confused operators.
Interestingly several different pre-driver transistors were used for the
under the playfield 2n5875 transistors. All on the driver board, some games
used the small MPS-A13 (Q17, Q18) and others used a larger 2n6043 (Q30, Q31.)
Generally if the item being controlled was a ball kicker or a drop target
bank, the larger 2n6043 (essentially a TIP102) was used as the pre-driver.
Also there was one odd exception to the use of the metal cased 2n5875 transistor
under the playfield. That was on Buck Rogers where a TIP115 (NTE262, PNP) was used.
(Note a TIP36c can be substituted.)
Games with Under the Playfield Transistors
| Game |
Coil |
Designator |
Pre-Driver |
PF Driver |
| Close Encounters |
Roto Target |
Sol.7 (Q30) |
2n6043 |
2n5875 |
| Count Down |
Yellow drop target bank |
L17 (Q17) |
MPS-A13 |
2n5875 |
| Blue drop target bank |
L18 (Q18) |
MPS-A13 |
2n5875 |
| Hulk |
Left Shooter |
Sol.6 (Q31) |
2n6043 |
2n5875 |
| Right Shooter |
Sol.7 (Q30) |
2n6043 |
2n5875 |
| Joker Poker |
Kings drop target bank |
L17 (Q17) |
MPS-A13 |
2n5875 |
| Pinball Pool |
Left drop target bank |
L17 (Q17) |
MPS-A13 |
2n5875 |
| Roller Disco |
Left drop target bank |
Sol.7 (Q30) |
2n6043 |
2n5875 |
| Torch |
Left drop target bank |
Sol.6 (Q31) |
2n6043 |
2n5875 |
| Asteriod Annie |
Left drop target bank |
Sol.7 (Q30) |
2n6043 |
2n5875 |
| Buck Rogers |
Vari-Target |
L17 (Q17) |
MPS-A13 |
TIP115 |
The Gottlieb System 1 CPU controlled solenoid arrangement.
From actual Gottlieb documents, so it's their property, but
modified by me so I guess it's their's and mine.
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Transistor Testing Overview.
After doing the ground modifications on the Driver board,
test all the transistors (which control the playfield lamps and
solenoids). It only takes a minute, it's real easy, and it
prevents problems after the board is installed.
NOTE 1: testing
transistors with a DMM is only about 95% certain to work. The DMM
is testing the transistors at "low load", which is unlike how
the transistors will ultimately be used in the game! MPS-U45
transistors are particularly prone to testing good, but
not working in the game.
NOTE 2: Any transistor that tests "bad" should also
have its playfield coil tested too as outlined
here. If the driver board transistor(s) are
replaced, but the playfield coil is burnt and has low resistance,
it will immediately blow the freshly replaced driver board
transistors.
Testing System1 Transistors with the Driver Board Removed.
MPS-A13 transistors (driver board locations Q5-Q24, Q33-Q44).
The MPS-A13 transistors are used for CPU controlled playfield lights.
These transistors test the same in circuit and out of circuit.
- Using a DMM (Digital Multi-Meter), put the meter on the "Diode"
setting.
- On the COMPONENT side of the board, put the RED lead of the DMM on the
middle trace (the base) of the transistor.
- Put the black DMM lead on the left transistor lead. This should show
about 1.3 (emitter - ground).
- Put the black DMM lead on the right transistor lead. This should show
about .7 (collector).
- Anything within .1 of these values is good.
- If getting zero or no reading for a test, that transistor is bad.
- If a reading of .4 to .6 is seen, good chance that transistor is probably bad too.
- If in doubt, compare the readings of the transistor in question to
the other surrounding transistors of the same type. They should all read about the same
value.
MPS-U45 transistors (driver board locations Q1-Q4, Q29).
The MPS-U45 is used for the tilt and game-over relays (Q2/Q1), and
a pre-driver for the 2N3055 transistor (Q29), and the High Game to Date and
Shoot Again backbox lights (Q3/Q4). Sometimes Q3 and/or Q4 are used
for pre-drivers to under the playfield mounted 2N5875 transistors.
The MPS-U45 transistors test the same in circuit and out of circuit.
- Using a DMM (Digital Multi-Meter), put the meter on the "Diode"
setting.
- On the COMPONENT side of the board, put the RED lead of the DMM on the
middle trace (the base) of the transistor.
- Put the black DMM lead on the left transistor lead. This should show
about 1.3 (emitter - ground).
- Put the black DMM lead on the right transistor lead. This should show
about .7 (collector).
- Anything within .1 of these values is good.
- If getting zero or no reading for a test, that transistor is bad.
- If a reading of .4 to .6 is seen, good chance that transistor is probably bad too.
- If in doubt, compare the readings of the transistor in question to
the other surrounding transistors of the same type. They should all read about the same
value.
2N6043 or SE9300 transistors (driver board locations Q30-Q32, Q25-Q28).
These are used for the sound/chime coils (Q26-Q28), the knocker (Q25),
the outhole kicker (Q32), and two other playfield devices (Q30/Q31).
This transistor tests the same in circuit and out of circuit.
- Set the DMM to the "diode" setting.
- On the COMPONENT side of the board,
Put the black lead on the center lead of the 2N6043 or SE9300
transistor, and the red lead on each leg one at a time. A reading of .4 to .6 for
each transistor leg should be seen. Anything else and this transistor is bad.
- The original 2N6043 or SE9300 transistor can be replaced with a TIP102.
2N3055 transistors (driver board Q45, large transistors with
the huge metal case, pre-driven by Q29). This transistor is usually used for a drop
target reset bank or other big coil usuage.
This transistor tests the same in circuit and out of circuit.
- Set the DMM to the "diode" setting.
- Put the black lead on the metal case (or nut/bolt) of the 2N3055, and the red
lead on each leg one at a time. A reading of .4 to .6 should be seen for the top leg, and null
reading for the bottom leg should be seen.
- Now put the red lead on the "base" (top) lead of the
transistor. Put the black lead on the bottom leg (emitter), and then
the metal case of the transistor (collector). A reading of .4 to .6
should be seen with the black lead on the emitter or collector.
- Any other readings and this transistor is bad and needs replacing
(they are about $1 each at Radio Shack).
- Remember the 2N3055 is pre-driven by a MPS-U45 at Q29. So if the
2N3055 tests bad, also suspect the pre-driver at Q29.
- Test the BIG 9.1 ohm 1 watt resistor next to the 2n3055. The resistor
should test as 9 or 10 ohms in circuit.
2N5875/2N5879/2N5883 Remote Playfield Mounted Transistors.
Some system1 games used more then eight controlled solenoids (which was all the driver
board allowed.) The first game to do as such was Joker Poker, as there were four drop target banks on the game,
yet only three solenoid drivers are available on the driver board. To get around this,
a remote mounted 2N5875 transistor (essentially a TIP36) was added under the playfield,
which used a MPS-A13 lamp transistor as a pre-driver transistor.
Some Gottliebs also used the more robust 2n6043 (essentially
a TIP102) as a pre-driver too. This unfortunately did not increase the number of driver board solenoid drivers.
Yet Gottlieb did this because they felt the MPS-A13 wasn't up to the task of being a pre-driver for a
very heavy duty coil (like a large drop target reset coil.)
Note remoted mounted (under the playfield) transistors are not used in
every System1 game. Here's a table of games with these transistor.
Games with Under the Playfield Transistors
| Game |
Coil |
Designator |
Pre-Driver |
PF Driver |
| Close Encounters |
Roto Target |
Sol.7 (Q30) |
2n6043 |
2n5875 |
| Count Down |
Yellow drop target bank |
L17 (Q17) |
MPS-A13 |
2n5875 |
| Blue drop target bank |
L18 (Q18) |
MPS-A13 |
2n5875 |
| Hulk |
Left Shooter |
Sol.6 (Q31) |
2n6043 |
2n5875 |
| Right Shooter |
Sol.7 (Q30) |
2n6043 |
2n5875 |
| Joker Poker |
Kings drop target bank |
L17 (Q17) |
MPS-A13 |
2n5875 |
| Pinball Pool |
Left drop target bank |
L17 (Q17) |
MPS-A13 |
2n5875 |
| Roller Disco |
Left drop target bank |
Sol.7 (Q30) |
2n6043 |
2n5875 |
| Torch |
Left drop target bank |
Sol.6 (Q31) |
2n6043 |
2n5875 |
| Asteriod Annie |
Left drop target bank |
Sol.7 (Q30) |
2n6043 |
2n5875 |
| Buck Rogers |
Vari-Target |
L17 (Q17) |
MPS-A13 |
TIP115 |
* Remote mounted TIP-115 (PNP) instead of a 2n5875.
(Alternatively a TIP36 or 2n5875 can be used.)
An under the playfield 2N5875 transistor.
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|
Schematic on Countdown for its two under-the-playfield 2N5875 transistors.
From actual Gottlieb documents, so it's their property.
|
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Modification for Remote Mounted Transistors.
With system80 games Black Hole and later, Gottlieb added a
pull up resistor to the circuit for the remote mounted transistors.
An added 4.7k ohm resistor tied the base of the remote transistor
to 24 volts (coil power), which was
mounted right next to the remote transistor under the playfield. This helped
prevent a locked on coil in case the driver board lost power.
The pull up resistor modification should be added to system1 games that
use remote mounted (playfield) 2n5875 transistors.
An under the playfield 2N5875 transistor with pull-up resistor mod.
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|
Remoted mounted transistor circuit with pull up resistor modification.
From actual Gottlieb documents, so it's their property.
|
|
Remoted mounted transistor modified with a pull-up resistor on a Joker Poker.
|
|
Problems with locked on solenoids? It could be a ground problem!
(See the mandatory ground modifications listed previously in this
document). Also, all the playfield grounds are discrete. They go
to a Molex plug, and then to a central copper grounding strip. If
one Moxlex pin gets resistance in the plug, this can cause a locked
on coil! To fix this, tie all the grounds together at the (playfield
side) connector. Then if one of two Molex pins fail, the path of least
resistance will be taken, and the coil will not lock on. (Electrical
tape was wrapped around this mess after this picture was taken.)
|
|
74175 chip Test and Q1-Q4 Transistor Test.
The 74175 chip at Z1 is what controls the transistors for the Game-Over
relay, Tilt relay and Q3/Q4 (if used to pre-drive an under-the-playfield
mounted transistor).
The rest of the 74175 chips are used for the CPU controlled lamps.
These chips can be easily tested with a DMM set to the diode
function and the game off. Best to do this with the driver board removed.
- On the COMPONENT side of the driver board (game off),
put the red lead of the DMM on the
74175 ground pin 8 (pin at the lower left of the chip).
- Probe pins 2-7 (top left is pin 1) and 10-16 (top right is pin 9)
with the black DMM lead. A value of .6 to .7 should be seen.
Anything else and likely the 74175 chip is bad.
- Pin 1 (top left) and pin 16 (top right) will show .3 to .4 on the meter
when probed with the black DMM lead.
The 74175 chip at Z1 can also be used to test the driver board
transistors at Q1-Q4 (Q1=Game Over relay, Q2=Tilt relay, Q3/Q4=any
under-the-playfield mounted transistors). With the game on,
attach an alligator clip to +5 volts (the positive/upper lead
of capacitor C1 on the driver board). Then touch the Z1 pins 2,7,10,15
with the other end of the alligator clip. This will tell the
transistors Q1-Q4 to activate its relay (or coil or lamp).
This is a good test to run if you are unsure if one of the Q1-Q4
transistors is really good. This test of course assumes that
the coil/relay being driven is not locked-on.
7417 chip Test (CPU board locations Z6,Z7).
The 7417 chips at Z6 (located just above connector J5)
and Z7 (to the right of Z6) can also be used to test the connection from
the CPU board to the driver board, and to test the
transistors at Q25-Q32 (all the CPU controlled coils).
With the game on,
attach an alligator clip to +5 volts (the positive/upper lead
of capacitor C16 on the CPU board). Then touch the Z6 pins 1-6 and
pins 8-13 (note pin 7=gnd and pin 14=+5). Each pair of pins (for example
Z6 pins 1,2) should fire its associated coil when attached to +5 volts.
The same thing can be repeated for Z7 pins 1-4 (only).
Refer to the above chart to see which Z6/Z7 pins control which
driver board transistor/coil. If only one of the two pairs of pins
activates the coil, the Z6 or Z7 chip is bad. If neither pin activates
a coil, check the CPU to driver board connector and the driver board transistor.
This test will tell the transistors Q25-Q32 to activate its coil.
This test of course assumes that the coil being driven is not locked-on.
If this test passes, yet a coil still does not work, then the problem
is most likely the U4 spider chip (which sends the signal to Z6/Z7 to fire
a coil). Unfortuantely the U4 spider chip is not available, and the
CPU board must be replaced with a NiWumpf or Pascal CPU board.
Can a CPU board Problem cause a Non-Working Coil?
Yes! Though not as common of a problem as a driver board issue,
there is a spider chip U4 (A1753-CE) which can go bad and
not make a coil work or make the coil lock-on. If this is
the case, sorry but there is no replacement available for
this U4 chip. The only choice is to buy a new NiWumpf or Pascal
CPU board. If using a NiWumpf
board there are also 7406 or 7416 Hex Inverter/buffer
chip at U12 and U13 which can fail
making a coil not work properly. On these chips check the input signal
to the chip, and then the output signal. They should be opposite of
each other (it's an inverter).
Earlier Solenoid Driver Boards on Cleopatra, Sinbad, Joker Poker -
Missing Diodes Preventing Coil Voltage Damage.
The first System1 revision of the Driver board as used on
Cleopatra, Sinbad, and early Joker Poker games were missing
driver transistor isolation diodes. These seven 1N4004 diodes were
added to the Driver board during the production run of Joker Poker.
If these diodes are not present, and a coil or driver transistor shorts,
this can cause serious damage to the CPU board, allowing 24 volts coil power
to back-feed to the CPU board, possibly ruining irreplaceable components.
Because of this, it is a good idea to check which driver board
is installed in your game. Even if you have a later System1 game,
check for these diodes (as the driver board could have been swapped
at some point).
Added diodes CR2-CR5 and CR1,CR6,CR7.
From actual Gottlieb documents, so it's their property.
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The diodes are easy to spot. At the top edge of the Driver board
just to the right of the A3J1 connector (going to the CPU board),
there should be four diodes (CR2-CR5). There are also three more
diodes (CR1,CR6,CR7) installed below Q32 and Q30 just above
connector A3J4. If these diodes are not there, you
have an earlier Driver board.
Factory added diodes on the Driver board. Early driver boards will
be missing these seven diodes.
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If your Driver board does not have these diodes, there are a few
options. Either add the diodes to your old driver board, get a different
driver board (Rottendog sells a replacement), or get a new Steve Kulpa
CPU to Driver board hardness.) If you want to add the diodes to an
old original driver board, you'll need to add
seven 1N4004 diodes for transistors Q25-Q28 and Q30-Q32.
This can be done a couple of ways. Below are
two pictures (thanks to J.Robertson) showing the modification.
Added diodes on the Driver board component side for Q28-Q25.
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Or added diodes on the Driver board solder side for Q25-Q28.
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Another easier way to add the diodes is to buy a new CPU to Driver
board harness, with the diodes installed into the harness! This is a
very cool idea, one that Steve Kulpa came up with. He sells this harness at
Big Daddy Enterprises,
and it's well worth the expense. Note using this harness with a Gottlieb driver
board that has the diodes is fine too. (So always buy this version of the harness!)
Steve Kulpa's CPU to Driver board harness with diodes installed.
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Modifying your Current Harness for Diodes.
On early system1 games (Joker Poker, Cleopatra, Sinbad) with
first generation driver boards (no CR1-CR7 diodes installed),
it's a good idea to modifying your current CPU to Driver board harness
to add diodes. This will protect your expensive CPU board from coil voltage damage
(if something goes wrong.) This modifiction saves you from having to modify the driver
board adding diodes, if it's missing the CR1-CR7 diodes. (Note this modified
harness can be used with later Driver boards too.)
Modifying an original CPU to Driver board harness with 1n4004 diodes.
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The point here is to add the CR1 to CR7 diodes, which are missing
on early driver boards, to the harness. This protects the CPU board
without having to do major modifications to the Driver board. If you're
already working on this harness, this is a good modification.
Finished modified original CPU to Driver board harness with 1n4004 diodes installed.
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Non-CPU Controlled Coils.
The Gottlieb System1 games also have several non-CPU controlled coils.
There isn't a lot to say about these coils, as their repair
is easy compared to the CPU controlled variants. On system1 games
the pop bumpers, slingshot kickers, flippers, coin door lock out coils
are all non-CPU controlled. This means that once the Game Over relay
is energized and the Tilt relay is de-energized, all the above coils have power.
(Exception: coin door lock out coil which always has power if the game is on.)
After a game ends and the Game Over relay turns off, the pop bumpers,
slingshots and flippers all turn "off." Likewise if during a game,
where the Game Over relay is energized, and the player tilts (thus
engaging the Tilt relay), again power to the pop bumpers, slingshots and
flippers all turn "off."
The Gottlieb System1 *NON* cpu-controlled coil arrangement.
From actual Gottlieb documents, so it's their property.
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The non-controlled coils are wired very similar to EM games, where the ball closes a
playfield switch, which in turn completes powers to the pop bumper
or slingshot. On pop bumpers and slingshots,
there's a secondary switch which closes when the
coil energizes that tells the CPU board to score points for
the device. Williams did something similar up to system11a
(but pops and slings had some CPU control, where on system1
games, there's no CPU control.)
If a System1 pop bumper or slingshot "locks on" and stays
energized, the reason for this is very simple; the playfield
switch which controls the device is stuck closed. If the
device does not work at all, start a game and check
for power at both lugs of the coil in question. No power
at either lug, check the solenoid fuse. Power at one lug
and the coil is bad. No power at either lug check the T (Tilt) relay
Normally Closed switch and the Q (Game Over) relay
Normally Open switch.
Also if you are working on a system1 machine and have the playfield "up",
the Game Over relay can be manually engaged. This should turn on power
to the non-CPU controlled coils like the pop bumpers, slingshots and flippers.
This is helpful if you are confused about which coils are CPU controlled,
and which are not. If you hold in the Game-over relay, only the non-CPU controlled
coils (like the flippers, pop bumpers, slingshots) will activate. This is a
nice easy test to do when working on non-CPU controlled coils.
3e. Locked-on or Not Working CPU Controlled Feature Lamps
On Gottlieb system1 games, there are three lamp circuits. Two are not CPU controlled,
and those are the GI (general illumination) 6.3 vac lamps used for the playfield
and backbox lights. These are #44 or #47 bulbs (though some backbox lamps may be #455 flashers
at the discretion of the owner.) There is a fuse for each GI circuit on the bottom
panel. Again these are not CPU controlled lamps (though the playfield GI circuit does
go through the Tilt relay, which can turn off the GI playfield lights when the game is tilts.)
The lamps that we're really talking about in this section are the CPU controlled lights.
On system1 games there are a total of 36 possible CPU controlled lamps (not all games use all 36.)
Again these are #44 or #47 bulbs, but their power is 6 volt DC (not AC), provided to
each the lamps in a "daisy chain." Also these
lamps are turned on and off by the CPU board through the driver board,
which turns the ground on or off for any particular lamp.
Power for the CPU controlled lamps goes through a fuse (lower blue arrow)
and a bridge rectifier (top blue arrow.)
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CPU Controlled Lamp Power.
Power for the CPU controlled lamps comes from the larger transformer on the bottom panel.
Then it goes through a bottom board fuse, and to a bridge rectifier. The bridge converts
this power from AC to DC, converting 6 volts AC to about 8 volts DC.
(Under load the 8 volts DC ends up at around 6 volts DC, as this voltage is not regulated.)
Now the power is "daisy chained" along the playfield, providing
each of the CPU controlled lamps with power. (There are also backbox CPU controlled lights
too, being Shoot Again and High Score to Date.)
If none of the CPU controlled
lamps are working, chances are good there is no 8 volts DC
for the lamps. With the game on, use a DMM set to DC volts
and 6 to 8 volts DC should be seen at all the CPU controlled
lamp sockets (use the game's metal coin door for ground.)
Power should be seen at both lamp socket lugs (if
power is only seen at one socket lug, the bulb is bad.)
The Gottlieb System 1 CPU controlled light arrangement.
From actual Gottlieb documents, so it's their property.
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Also keep in mind that the power for all the CPU controlled lamps goes
through a Normally Closed switch on the T (Tilt) relay. If the
Tilt relay is energized (because the player tilted during game play),
there will be no CPU controlled lights.
If the switch activator plate on the Tilt relay is
knocked off the relay's frame, this can cause the Normally Closed
CPU lamp power switch to open, meaning no power for the CPU lights.
Also if the driver board Q2 transistor is shorted, this would
keep the Tilt relay permanently energized meaning no CPU controlled
lights.
If there is no power at the CPU controlled lamp sockets,
check the 8 volt fuse in the bottom cabinet (5 amp slow-blow).
If the fuse is good, also check the bridge rectifier closest
to the copper ground strap. It is common for this bridge
to go open or short (if shorted its fuse will blow immediately
at power-on). If the bridge is suspected as bad, replace it with a new
MB3502 or MB3504 lugged 35 amp 200 (or 400) volt bridge rectifier.
If all the CPU controlled lamps are dim, the bridge is weak
and should be replaced with a new lug-lead 35 amp 200 volt
(3502) bridge.
A suspect bridge can be tested.
Use a DMM set to diode function and test the bridge:
- Put the DMM on diode setting.
- Put the black lead of the DMM on the "+" (positive) terminal of the bridge.
- Put the red lead of the DMM on either AC bridge terminal.
Between .4 and .6 volts should be seen. Switch the red DMM lead
to the other AC bridge terminal, and again .4 to .6 volts should be seen.
- Put the red lead of the DMM on the "-" (negative) terminal of the bridge.
- Put the black lead of the DMM on either AC bridge terminal.
Between .4 and .6 volts should be seen. Switch the black DMM lead
to the other AC bridge terminal, and again .4 to .6 volts should be seen.
Using the Game's Diagnostic Lamp Test.
One of the worst features of a system1 game are the built in diagnostics.
To say they are terrible would be an understate. Diagnostic test #13
really doesn't help much. What it does is turn on ALL the CPU controlled
lamps for about 5 seconds. Then they all go off. That's it, lamp test over, and
the test doesn't even repeat (it then cyles to testing the coils and then switches.)
Also in attract mode before a game starts,
system1 games don't cycle the CPU lamps. (This is rather odd,
though Bally and Williams games did that too for their first few titles.)
So really the best way to test a CPU controlled lamp is to play a game,
and trigger that lamp function in the game.
Bad Lamp - Check Simple Things First (Bulb & Socket.)
Of course there are a couple assumptions we need to state when checking
lamps. First, is the lamp itself good? Sure you can try and look at the
filament of the lamp - if broken the lamp is definitely bad. But a better
way is to use your DMM set to low ohms or continuity. A good #44 or #47 bulb will show
about 4 ohms of resistance. Or just check the bulb in question in one of the
game's GI lamp sockets to see if it lights.
Additionally the lamp sockets in any system1 game are 30+ years old.
Lamp sockets do go bad. If you're sure the bulb is good, a twist of
the bulb in the socket can often wake up a marginal lamp socket.
A single drop of 3-in-1 oil on the fiber gasket of a lamp socket can often
help (the oil swells the gasket, forcing the metal pieces together.)
Sanding the inside of the socket isn't really a good choice, as the naked
metal will quickly tarnish again, as the zinc corrosion resistant plating
is worn away. A better approach is to just replace the lamp socket.
Again remember on the CPU controlled lamp sockets, you can check for
power at the socket (with a good bulb installed) using a DMM. Red DMM lead
on either lug of the socket, black DMM lead on ground (metal coin door.)
You should see 6 volts DC. If you only get 6 volts on one socket lug, the bulb is bad.
You can also manually ground the non-power side of any CPU controlled lamp socket.
Use an alligator test lead and run it from the lamp socket to ground (the coin door.)
The lamp in question should light. If not, the bulb or socket (or socket power) are bad.
The Driver Board and CPU Controlled Lamps.
Now that the power to the lamps is established as good,
we can move to the driver board.
Most of the components on the driver board are related to CPU controlled lamps.
The nine 74175 chips (Z1-Z9) and transistors Q3,Q4 (MPS-U45) and
Q5-Q24/Q33-Q44 (L5-L36, MPS-A13) control a total of 36 lamps (or 34 lamps
and two solenoids).
The lamps are controlled in groups of four with a 74175 chip
driving four transistors. The MPS-A13 can drive a single
lamp, where the MPS-U45 can drive two lamps. In addition, the
MPU-U45 can be used as a pre-driver for an under-the-playfield
mounted 2N5875 transistor. But since there are only two MPS-U45 transistors
available (Q3,Q4) on the driver board, there
can only be two under-the-playfield mounted driver transistors.
See the Locked-on Coils section for more
details about that.
A single wire goes from
each CPU controlled lamp socket back to the driver board,
connecting to its related transistor.
The driver transistor (MPS-A13 or MPS-U45) switches ground
on through the 74175 chip to illuminate its respective lamp.
Hence if any of these single wires are manually grounded with the
game on, its respective lamp should light. This can be done
easily by using an alligator test lead with one end connected
to copper ground strip on the game's bottom panel or any metal
cabinet frame piece in the backbox or the coin door.
Then touch the other end of the test lead to the
right-most leg of a MPS-U45 or MPS-A13 transistor (as facing the driver
board installed in the backbox). This tests the connection from
the driving transistor to the lamp socket (it does not, however,
test the transistor). If the lamp does not
light when grounding the transistor leg (and the bulb/socket are good),
suspect a bad driver board connector or broken wire (or a bad bulb or light socket).
Often lightly sanding the driver board's connector "fingers"
can fix a non-working lamp. Or the connector pins may need to be
replaced (very common).
Note a good number of non-working lamp problems are related
to connectors. If the .156" single sided Molex connectors at the driver
board are in poor condition, this, of course, will mean a lamp
will not work. Before attempting driver board repair, check
all card edge connectors attaching to the driver board, and
re-pin the connectors as needed. See the
Connector section of this document
for help with that.
If grounding the right leg of any MPS-A13 transistor does
light a CPU controlled lamp, but the lamp refused to
working in diagnostic or game mode, next test the transistor
in question.
The Gottlieb System 1 driver board transistor layout.
From actual Gottlieb documents, so it's their property.
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Testing the Driver Board Transistors and Chips.
Each lamp is driven by a 74175 chip and a MPS-A13 or MPS-U45 transistor
on the driver board.
If a 74175 chip totally fails, it causes four lamps to stop working,
and those lamps can either stay always on or off (depending on how
the 74175 failed). If a driver transistor fails (which happens far
more often than a failed chip), it affects only one
lamp. A brightly lit lamp is a sign of a failed driver transistor.
A non-working lamp is also a sign of a failed driver transistor (assuming
the transistor leg grounding trick does light the lamp).
Note the MPS-A13 transistors damage easily if the 8 volts driving the lamp
gets shorted directly to its grounding wire with no load (no bulb),
usually by a bad lamp or bad lamp socket.
MPS-A13 Transistor Test (driver board locations Q5-Q24, Q33-Q44).
For a non-working lamp (that has a good bulb/socket and connector),
test the MPU-A13 driving transistor first.
The MPS-A13 transistors are used for CPU controlled playfield lights.
These transistors test the same in circuit and out of circuit.
Best to do this with the driver board removed.
- Using a DMM (Digital Multi-Meter), put the meter on the "Diode"
setting.
- On the COMPONENT side of the board, put the RED lead of the DMM on the
middle trace (the base) of the transistor.
- Put the black DMM lead on the left transistor lead. This should show
about 1.3 (emitter - ground).
- Put the black DMM lead on the right transistor lead. This should show
about .7 (collector).
- Anything within .1 of these values is good.
- If getting zero or no reading for a test, that transistor is bad.
- If a reading of .4 to .6 is seen, good chance that transistor is probably bad too.
- If in doubt, compare the readings of the transistor in question to
the other surrounding transistors of the same type. They should all read about the same
value.
MPS-U45 Transistor Test (driver board locations Q1-Q4, Q29).
The MPS-U45 is used for the tilt and game-over relays (Q2/Q1), and
a pre-driver for the 2N3055 transistor (Q29), and the High Game to Date and
Shoot Again backbox lights (Q3/Q4). Sometimes Q3 and/or Q4 are used
for pre-drivers to under the playfield mounted 2N5875 transistors.
The MPS-U45 transistors test the same in circuit and out of circuit.
Best to do this test with the driver board removed.
- Using a DMM (Digital Multi-Meter), put the meter on the "Diode"
setting.
- On the COMPONENT side of the board, put the RED lead of the DMM on the
middle trace (the base) of the transistor.
- Put the black DMM lead on the left transistor lead. This should show
about 1.3 (emitter - ground).
- Put the black DMM lead on the right transistor lead. This should show
about .7 (collector).
- Anything within .1 of these values is good.
- If getting zero or no reading for a test, that transistor is bad.
- If a reading of .4 to .6 is seen, good chance that transistor is probably bad too.
- If in doubt, compare the readings of the transistor in question to
the other surrounding transistors of the same type. They should all read about the same
value.
74175 Chip Test (driver board locations Z1-Z9).
The 74175 chips is what controls the lamp (and solenoid) transistors,
with each 74175 chip on the driver board controls four lamps.
The 74175 chips can be easily tested with a DMM set to the diode
function. Best to do this with the driver board removed.
- On the COMPONENT side of the driver board (game off),
put the red lead of the DMM on the
74175 ground pin 8 (pin at the lower left of the chip).
- Probe pins 2-7 (top left is pin 1) and 10-16 (top right is pin 9)
with the black DMM lead. A value of .6 to .7 should be seen.
Anything else and likely the 74175 chip is bad.
- Pin 1 (top left) and pin 9 (top right) will show .3 to .4 on the meter
when probed with the black DMM lead.
Lamp Signal
(CPU encoded
at U3) |
CPU Decoder
74154 |
CPU Inverter
7404 |
CPU Connector |
Driver
Connector |
Driver
74175 |
Driver
Transistor |
Lamp # |
Driver
Connector
to Lamp |
| DS1 |
z30 pin 2 |
z24 pin 1,2 |
a1J5 pin 21 |
a3J1 pin 5 |
z1 |
Q1-Q4 |
L1-L4 |
J5 pin18,19,17,15 |
| DS2 |
z30 pin 3 |
z24 pin 3,4 |
a1J5 pin 20 |
a3J1 pin 6 |
z2 |
Q5-Q8 |
L5-L8 |
J5 pin13,14,12,11 |
| DS3 |
z30 pin 4 |
z24 pin 5,6 |
a1J5 pin 19 |
a3J1 pin 7 |
z3 |
Q9-Q12 |
L9-L12 |
J5 pin9,10,8,7 |
| DS4 |
z30 pin 5 |
z24 pin 13,12 |
a1J5 pin 18 |
a3J1 pin 10 |
z4 |
Q13-Q16 |
L13-L16 |
J5 pin5,6,4,3 |
| DS5 |
z30 pin 6 |
z24 pin 11,10 |
a1J5 pin 17 |
a3J1 pin 13 |
z5 |
Q17-Q20 |
L17-L20 |
J5 pin1,2
J3 pin20,18 |
| DS6 |
z30 pin 7 |
z25 pin 1,2 |
a1J5 pin 16 |
a3J1 pin 14 |
z6 |
Q21-Q24 |
L21-L24 |
J3 pin16,17,15,14 |
| DS7 |
z30 pin 8 |
z25 pin 13,12 |
a1J5 pin 14 |
a3J1 pin 15 |
z7 |
Q33-Q36 |
L25-L28 |
J3 pin12,13,11,9 |
| DS8 |
z30 pin 9 |
z25 pin 3,4 |
a1J5 pin 15 |
a3J1 pin 16 |
z8 |
Q37-Q40 |
L29-L32 |
J3 pin7,8,6,5 |
| DS9 |
z30 pin 10 |
z25 pin 11,10 |
a1J5 pin 13 |
a3J1 pin 17 |
z9 |
Q41-Q44 |
L33-L36 |
J3 pin4,3,2,1 |
How do I know which Transistor Controls Which Lamp?
If the schematics are not available, the easiest way to
do this is by lamp socket wire color. For a failed lamp,
look at the wire color that connects to its lamp socket, and
make a note of it.
With the game powered off,
go to the driver board and examine the connectors along
the bottom edge of the driver board. Find the wire color
in question and make note of the connector and pin.
Using a DMM set to continuity, put one lead of the DMM on
the pin with the correct wire color. Then probe the RIGHT leg
of each transistor on the driver board. When a continuity
buzz is heard, the transistor controlling the lamp in question
has been found.
To double check you have found the correct
transistor, power the game on. Now use an alligator test lead
and connect one end to ground. Momentarily touch the other
end of the alligator test lead to the RIGHT leg of the transistor.
The CPU controlled lamp should light.
Four Lamps Don't Work.
From the table above you can see that any 74175 chip on the driver
board controls four lamps. It's easy to suspect one of the 74175 chips
as bad, but that's usually not the case in my experience. A far bigger
thing to suspect is the connector coming from the bottom edge of the CPU
board to the top edge of the driver board. Battery corrosion and age often
takes its toll on these connectors, and the lamp signal gets lost from from the CPU
board's spider chip to the 74175 driver board chip. Also on the CPU board the
z24 or z25 (7404) inverter chip likes to die too.
Summary of CPU controlled Lamps.
For a non-working lamp, always start with checking power at the socket
and if the bulb/socket itself are good. Then work up the chain to the
driver board transistor, grounding it's right leg to see if the lamp goes on.
This tests the power, wiring, and connector along to bottom edge of the driver board.
Now the transistor itself can be tested, and potentially the 74175 chip that
controls it. Next suspect the connector between the driver board and CPU board.
Then on the CPU board look at the 7404 inverter chips at z24/z25. Next is the
74154 decoder chip at z30 - this gets the encoded signal from the spider chip U3.
Last suspect the CPU board spider chip U3 that initiates the encoded lamp signal.
Semi-CPU Controlled Lamps.
There are two backbox lamps that are
what I call "Semi-CPU controlled". That is
the Game-Over lamp and the Tilt lamps. Both of these
lamps run on 6.3 volts AC (the General Illumination power),
but they are not GI lamps.
The 6.3 volts AC power for the Tilt lamp
goes through a Normally Open switch
on the Tilt relay. The Tilt relay is then controlled
by the CPU board. If during game mode the machine is
tilted, the Tilt relay energizes and stays energized
until the current ball drains. While the Tilt relay
is energized, this closes the switch to the Tilt lamp,
turning the Tilt lamp on. Hence the semi-CPU control
of the Tilt lamp.
The Game-Over lamp works in a similar manner. The 6.3 volts AC
for the Game-Over lamp goes through a Normally Closed switch
on the Game-Over relay. The Game-Over relay is controlled
by the CPU board. When a game is started, the Game-Over relay
energizes for the duration of the game (enabling power to the
flippers, etc.) This opens the
Game-Over lamp switch, turning the Game-Over lamp off
while a game is played. Hence the semi-CPU control
of the Game-Over lamp.
3f. Switches and the Switch Matrix
There's two kinds of switches in any system1 game. High power (tungsten contact)
switches at carry 24 volts, and low power (gold flashed) switch matrix switches
that carry 5 volts. We'll be talking mostly about the switch matrix switches.
High power switches (like flipper EOS, flipper cabinet, pop bumper activation,
sling shot activation switches and some relay switches)
are all high power tungsten contact which carry 24 volts DC.
The larger contacts allow the EMF (electromotive force) to arc
and not burn the contacts.
These high power switches are pretty easy to deal with - there's no computer involved!
You can actually file these switches too. Now the gold flashed switch matrix
switch you can't file, so please don't try! You will ruin the switch contacts
if you do, causing more problems than you're solving.
Low power gold flashed inlane/outlane switches. These are part of the
switch matrix, and should *never* be filed. Note the lack of diodes mounted
on these switches - they do in fact have diodes, just Gottlieb didn't mount
the diodes directly on the switches themselves.
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The Switch Matrix.
The way the computer talks to the playfield is via switches. Not just any
switches, but low power (5 volt), gold flashed switches. So the computer can
"scan" switches quickly to see which are opened or closed, the switches are
organized into a "matrix" (no not the movie.) Being in a matrix allows the
CPU to quickly see what switches are open or closed, many times a second.
This is needed as things happen fast on that pinball playfield.
The System1 switch matrix consists of five strobe lines (Strobe0 to Strobe4)
and eight return lines (Return0 to Return7). This makes for a total of
5x8 or 40 switches in any System1 game. The switches are numbers
as such: 00-04, 10-14, 20-24, 30-34, 40-44, 50-54, 60-64, 70-74.
The computer can scan the strobe lines and look for a closure through
the return lines. If a strobe is seen through a return, the cross of those
two lines indicates an individual switch closure.
The first five switches (return line #0, switch numbers 00 to 04)
are consistent in all system1 games:
- 00 = test/play button
- 01 = coin chute #1
- 02 = coin chute #2
- 03 = credit (start) button
- 04 = tilt
Outside of the switch matrix, there are three common switches used in all System1 games.
These three switches are not part of the switch matrix. This includes
two slam switches and the outhole switch. All system1 games have
two slam switches - the first is a weighted Normally Closed (NC) switch on the coin door.
The second slam switch is also a Normally Closed switch, located at the end of the
ball roll tilt cage. The two slam switches and the outhole switch do NOT have a switch matrix
number designations. More info on these switches is in a section below...
Switch matrix table from a Joker Poker.
This document is from the Joker Poker manual, so it belongs to Gottlieb.
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All Switch Matrix Switches Have Diodes.
Because of the scanning of the strobe and return lines
in the switch matrix, diodes (one way applicators) are used
so there's no "cross talk" between switches. If there were no
diodes on the switches, a single switch closure would make
the computer think all switches on that strobe line were closed.
Gottlieb implemented switch diodes
a bit differently than other companies. Nearly all other pinball
makers mounted diodes directly on the switches themselves. Gottlieb
however didn't do that - they mounted the switch diodes on small
bakelite insulator boards under the playfield and away from the
actual switches involved. This left less confusion
when hooking up a new switch (how is the diode wired to the switch?),
but created more confusion if you were
used to working on other makers' games. Gottlieb also used 1n270 switch
diodes opposed to 1n4001 diodes like other makers.
Switch diode boards as used on a Joker Poker, mounted under the playfield.
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Switches Outside the Switch Matrix - Slam & Outhole.
There are additional switches that are consistent on
every System1 game, and that are outside of the switch
matrix. These are the two slam switches (CPU A1J6 pin 2) and the
Outhole switch (CPU A1J7 pin 1.) These switches are
activated by touching them to ground. In the case of the
Slam switches, they should be permanently tied to ground
or the game won't play or boot - the score displays will just
"strobe" very fast immediately upon power on (no five
second bootup delay). If either Slam switch is opened (disconnected
from ground) during attact mode or game play, again the score displays will
"strobe" very fast and the game will lock up until the slam switches are closed.
All system1 games have
two slam switches - the first is a weighted Normally Closed (NC) switch on the coin door.
The second slam switch is also a Normally Closed switch, located at the end of the
ball roll tilt cage. The two slam switches and the outhole switch do NOT have a switch matrix
number designations.
On the Ni-Wumpf board, there is no slam switch (it was completely
removed from the circuit because of the problems it causes with
stock Gottlieb System1 CPU boards). Also the Outhole switch is
shown on the Ni-Wumpf switch test as switch number 15 (which is
clearly outside of the 10-14 return1 row of switches). On the Gottlieb
System1 switch test the outhole switch is shown as switch number 12
(which is clearly is not, but that's how the test shows it).
Coin Door Switches - a Common Switch Matrix Problem.
Because system1 games do not have a free-play setting,
users often press the coin switches
inside the coin door with their fingers to add credits. This is fine, but while
doing this often the user will move the
"lock-out wire" so it touches one of the coin switch blades.
This will short that return/strobe switch matrix line to ground, making the
game freak-out. Usually a game won't start, or there will be
some other strange game behavior. The game may not even boot,
or may act like it is always tilted or slam tilted.
Coindoor lock-out wire shorting against a coin switch (blue arrow.)
The red arrow shows how the insulating fish paper is mis-placed. Note the
coin mech has been removed to show this issue.
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So first thing before doing any switch matrix board work, check
the two coin switches and make sure the lock-out wire is
not touching the metal coin switch blades. Insulating "fish paper"
is used by the factory to help prevent this problem.
Common Switch Problems (the Easy Stuff.)
Two common switch matrix problems are dirty switch contacts
and mis-adjusted switch blades.
Cleaning Dirty Switches.
When a switch doesn't work, the best first step is to clean
the switch contacts. Why do they get dirty? See all that black dust under the playfield?
That gets on the switch contacts. With gold flashed switch matrix switches,
use some alcohol (90%) and a small rag. Then wipe off dirt from switch contacts
with the alcohol wet rag. Or you can take a business card, and run it between the switch blades (cleaning
the contacts), with the blades manually closed. Another trick is to wet the business card
with alcohol, and run it between the switch contacts (this will clean the contacts better
than a dry business card.)
Again, remember, do NOT file gold flashed switch matrix contacts!
The other problem that comes up a lot are mis-adjusted switches.
Either the gap is too large between the two switch blade contacts,
or the two contacts are too close or even permenantly closed. (A permenantely closed
switch will be ignored by the switch matrix.) Switch blades should be
bent so there's a 1/16" to 1/8" gap between the contacts. Too close
and vibration will close the switch, too wide and the switch may never close.
Mis-Adjusted Switches.
Note you can easily mis-bend switch blades. One of the switch blades
will have a dampner. This is easy to mis-bend, shorting the two switch
contacts together. (See picture below.) Obviously you don't want to do that.
Another common problem with mis-adjusted switches occurs after
new playfield rubber has been installed. New rubber has different
tension, and can pull blades together more than old rubber,
permenantly closing the switch. This is really a problem on
non-computer controlled slingshots, where the sling shots can
"machine gun" or even lock-on if the contacts are too close.
A problem with CPU controlled switches too, but mostly because
it messes up the scoring (and generally doesn't lock on anything.)
Here's a mis-adjusted Gottlieb switch blade pair, where the
dampening blade is shorting the two contact blades together.
Obviously this is a bad thing.
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Dirty Switches, Random Scoring, and NiWumpf MPU Board.
One problem with the new replacement NiWumpf MPU board is random scoring.
This happens on games with drop targets. When the targets are down,
the drop target associated with each switch is closed. As the game vibrates,
a dirty closed drop target switch can quickly toggle open and then closed, due to
crud on the switch contacts. This is known as switch bounce.
On a stock Gottlieb system1 MPU board this switch bounce isn't a problem - the CPU
isn't fast enough to "see" a dirty switch bounce open and closed. Yet on a NiWumpf
board, the CPU is fast enough to see switch bounce. To help diagnose
this problem, NiWumpf has a switch test diagnostic option. In this test, the player3
display shows the current switch just closed (with no sound as the switch closes.)
If the NiWumpf sees switch bounce, it displays a message in the player1 and player2
displays saying "clean switch", and sounds the 10 point sound. So if in the NiWumpf switch test
you hear a sound when a switch is closed, the NiWumpf thinks that switch is dirty.
Joker Poker with a NiWumpf MPU board installed and in switch test.
Note the message "clean switch", indicating a dirty switch causing switch bounce.
This can be a problem on games with drop targets, causing random scoring.
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To fix this problem use a rag wet with alcohol and clean the switch contacts.
(Never use a file, as these are gold flashed contacts.)
This should fix the "clean switch" error. This should resolve any random scoring
happening in a system1 game with a NiWumpf MPU board.
CPU Board Switch Matrix Plugs.
If a switch doesn't work, yet it is clean and adjusted properly,
another common problem is the switch connector on the CPU board.
There are two plugs responsible for the switch matrix
on the CPU board. They are both directly below the battery,
so often these two plugs need to be re-pinned (due to battery
corrosion) for the game to work properly. This is a HUGE problem
on system1 games. It's not uncommon to re-pin all the switch
matrix CPU plugs on a system1 game due to corrosion and wear and tear.
The two switch matrix plugs on the CPU board, right below the battery.
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System1 Switch Matrix
| |
Strobe 0
Blue 011 |
Strobe 1
Org 022 |
Strobe 2
Brn 033 |
Strobe 3
Grn 044 |
Strobe 4
Purp 055 |
Return 0
Yel 066 |
Sw #00
Test |
Sw #01
Coin1 |
Sw #02
Coin2 |
Sw #03
Start |
Sw #04
Tilt |
Return 1
Blue/Wht 100 |
Sw #10 |
Sw #11 |
Sw #12 |
Sw #13 |
Sw #14 |
Return 2
Org/Wht 122 |
Sw #20 |
Sw #21 |
Sw #22 |
Sw #23 |
Sw #24 |
Return 3
Brn/Wht 133 |
Sw #30 |
Sw #31 |
Sw #32 |
Sw #33 |
Sw #34 |
Return 4
Grn/Wht 144 |
Sw #40 |
Sw #41 |
Sw #42 |
Sw #43 |
Sw #44 |
Return 5
Purp/Wht 155 |
Sw #50 |
Sw #51 |
Sw #52 |
Sw #53 |
Sw #54 |
Return 6
Yel/Wht 166 |
Sw #60 |
Sw #61 |
Sw #62 |
Sw #63 |
Sw #64 |
Return 7
Yel/Blk 366 |
Sw #70 |
Sw #71 |
Sw #72 |
Sw #73 |
Sw #74 |
Switch matrix from Charlies Angles. Note how Gottlieb docuements their
switch matrix reverse of other manufacturers. Usually the returns are rows,
and the strobes are columns. For some reason Gottlieb reverses this in
their drawings. This picture is from Gottlieb documents and is their property.
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Remember the coin door switches (or any playfield switch) also do not have their
diodes mounted on the switches. Like the playfield switches,
the coin door switch diodes are mounted elsewhere. In this
case, the coin door switch diodes are on the bottom panel next to the
ground plane and auxiliary power plug.
The coin door switch diodes, mounted on the bottom board.
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Shorting GI or Solenoid Voltage to the Switch Matrix.
One very big problem with Gottlieb system1 games is
if somehow the solenoid voltage (24 volts DC) or
General Illumination voltage (6.3 volts AC) is shorted
to the switch matrix. This can happen if someone is
poking around inside a powered-on game with a screwdriver.
Or it could happen because of a mis-installed coil,
or even a switch wire breaks and somehow shorts to
coil or GI voltage.
If any of these scenarios happen, a couple things
can happen. Almost certainly the 7404 chip at Z8
(the strobe0-strobe4 buffer chip) can fail. Also the
7405 chip at Z9 (return0-return5 buffer) and Z28 (return6-return7 buffer)
can also fail. This is not a huge deal as these chips are
readily available. But behind the 7404/7405 chips is
the irreplacable U5 (A1752CX) spider chip. If this
chip fails, the CPU board is junk and cannot be fixed,
because this spider chip is no longer available and
impossible to find.
J.Robertson is currently testing a modification
to the CPU board to prevent the over
voltage getting to the irreplaceable U5 spider.
He has added clamping 1N4004
diodes to the circuit. These can be placed across
the resistors R65-R72 with the band of the diode
soldered to the +5VDC end of the
resistor, and the non-banded end to the other side of
the resistor. Then on resistors R57-R62, connect
the non-banded end of the diodes to the
junction of the resistor and the trace leading to
the IC, and the banded end to a convenient +5 volt point.
J.Robertson's System1 CPU modification to protect the U5 spider chip from over-voltage.
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The idea is that there are a pair of 1N4005 diodes on
each strobe and return line. This should prevent the return/strobe
lines from going above +5 volts, thus protect the U5 spider chip
from the 24 volt DC solenoid bus or the 6.3 volt AC GI power.
Using the Diagnostic Test for the Switches.
Again, as with the lamp test, diagnostic test #13 can be used
to test switches. Don't sit down when doing this, this test goes
fast! First the lamps are tested for 5 seconds, then the eight CPU
controlled coils/sounds. Last the switch test. If no switch is seen
"tested" within 5 seconds, the game goes back to attract mode.
(Not a very friendly test.) This is also the slowest switch test
I've ever seen, as the reaction time from switch closure to the
switch number displaying on the credit/ball display is slooow.
One advantage to the diagnostic test #13 for switches is if there's
a short in the switch matrix. This test will show for example all
the switch in a particular strobe or row that are shorted, in lowest
to highest order. Like if strobe #1 is shorted, switches #1,11,21,31,41,51,61,71
will all show in the switch test.
The other switch tests described below won't give this information.
So for certain situations, test #13 is worth the trouble.
Before starting the switch test,
it's best to have all the drop targets "up",
so all the playfield switches are "open."
The ball can stay in the outhole, as technically
it's not part of the switch matrix (though it does show up in the
test as switch #12.) Because of this, it's best to remove the ball
from the game to avoid any confusion. After the lamp and coil tests are done, quickly test the switch
you want to test. The switch number should show up on the credit/ball
display.
Personally I find the best way to test system1 switches is in game mode.
This version of "switch test" is far easier, less stressful, and quicker.
Another Version of the Switch Test (Switch Display Ficker Test.)
For some strange reason, when a system1 games is in attract mode, and
a switch matrix switch is closed, the score displays "flicker" for just a
moment. Until you have seen it, it's hard to explain, but these system1
games do it. It's an extremely fast flicker, so the score displays have
to be in good shape and bright to see it.
But instead of using diagnostic test #13 or starting a game,
this is another alternative way to test switches. (Though personally
I find testing switches in game mode far easier as there's both visual
and sound verification of a switch closure.)
The one advantage to the attract mode flicker switch test is that
parallel switches can often be seen in this mode. For example, 10 point
switches. Often there are multiple 10 point switches on a game (behind
the drop targets, redundant sling shot switch, bouncing rubber switch, etc.)
If one of these parallel 10 points switches are permanently closed,
NONE of the other 10 points switches will work during game play.
But using the attract mode flicker switch test, often a parallel
switch closure can be seen.
Switch Matrix Problems.
If the switch matrix is not working correctly, the best approach
is to use a logic probe to check the return and strobe lines.
First with the game off,
defeat the Slam switch right on the
CPU board (if you have not done that already).
Then turn the game on and let it boot. Now remove CPU switch
connectors J6 and J7. Now take a logic probe and
check the following chip pin number for the appropriate activity.
Note the first pin number listed below connects to the U5 spider chip,
and the second pin number goes to the board connector.
Z8 - 7404 (switch Strobes):
This is the chip that fails most often (more so
than the return line chips).
- Z8 pin 1/2 = Strobe0: both pins pulsing.
- Z8 pin 3/4 = Strobe1: both pins pulsing.
- Z8 pin 5/6 = Strobe2: both pins pulsing.
- Z8 pin 9/8 = Strobe3: both pins pulsing.
- Z8 pin 11/10 = Strobe4: both pins pulsing.
- Z8 pin 13/12 = Strobe5: both pins pulsing (not used in any system1 games).
If the logic probe shows pulsing just on the input side of the 7404 (first
pin listed above) and not on the output pin, then the 7404 chip at Z8 is bad.
If incorrect activity (no pulsing) is seen on the input side
of the 7404 chip, then the U5 spider chip is bad.
Z9/Z28 - 7405 (switch Returns):
- Z9 pin 2/1 = Return0: both pins high.
- Z9 pin 4/3 = Return1: both pins high.
- Z9 pin 6/5 = Return2: both pins high.
- Z9 pin 8/9 = Return3: both pins high.
- Z9 pin 10/11 = Return4: both pins high.
- Z9 pin 12/13 = Return5: both pins high.
- Z28 pin 4/3 = Return6: both pins high.
- Z28 pin 10/11 = Return7: both pins high.
3g. Score Display Problems and Fixes
Warning!
Do not remove or attach CPU connectors J2 and J3 (the right side score display
connectors) with the game power on. Do not remove a score display
with the game power on. Doing either of these with the power on
will likely damage the CPU board score display driver chips, usually Z16-Z17
(digit control) and/or Z13-Z15 (ones control) and/or Z18-Z21 (digit selection).
Sometimes the score display's UDN6116 chip blows too.
Also be aware that the score displays run at higher voltages (60 volts.)
So just keep that in mind and don't shock yourself.
Potential Display Problems.
There's only about three things that can be wrong with non-working
score displays: No power (power supply problem),
bad score display glass and/or board, and/or
bad CPU data going to the displays.
Is there Score Display Power?
If none of the score displays work, the first course of action is to test
the display power. Power comes to the power supply A2 board,
which develops all the voltages for the score displays from the bottom board AC power.
There's a 1/4 amp 69 volt fuse (right most fuse) on the bottom board. If that's
blown, obviously there won't be any power to the score display. DO NOT
over fuse! It's 1/4 amp for a reason. If you over fuse this, and a score
display or power supply has a short, it can ruin the main power transformer.
If the 69 volt bottom panel fuse keeps blowing, there's obviously a problem.
To diagnose this first remove the right side J3 power supply connector. Power up
with a good bottom board 1/4 amp fuse. If the fuse still blows, the problem
is on the power supply board. Diodes CR6-CR9 (1n4004) often short, and can
immediately blow the 1/4 bottom board fuse. These are easy to test with a DMM
set to diode function (should see .4 to .6 volts.)
If the bottom board 1/4 amp fuse is not blowing, next check the power output
at connector J3 with a DMM. Remember the ground connection for the 60/42 volt score display
power is different than the other grounds. So you must use power supply connector J3 pin 5
as your ground reference when measuring 42 or 60 volts.
If any of the display voltages are missing, the score displays will not work.
- A2 J3 pin 1 = 60 vdc (top most pin)
- A2 J3 pin 3 = 42 vdc
- A2 J3 pin 5 = Ground (common)
- A2 J3 pin 7 = 4 vdc
- A2 J3 pin 8 = 8 vdc
The 60 volts is used for the larger 6 digit display main power, along with the 8 volt
"reference" voltage. The credit/status display uses 42 volts for it's main power, and
4 volts as its "reference" voltage. This is all suppled by the power supply connector
J3, so check the voltages there using J3 pin 5 as ground. The 60vdc and 42vdc power lines
come from the 69vac bottom board voltage. The 4vdc and 8vdc reference voltages come from
the 11.5 vac supplied by the bottom board.
Once you have verified that the power supply is working, turn off the game and re-connect
the J3 power supply connector. Power back up and check the voltages again. They should
be about the same. Note there is a pot to adjust the 60 volts on the original Gottlieb power supply.
(You can "dial in" that voltage if you so desire.) If the score displays still don't work
(and the CPU board is booting), then there could be a CPU data problem, or bad displays themselves.
Bad Score Display Glass and/or Display Board Chips.
It happens, score display glass does go bad. If
you see white corners on the glass, chances are good that the display glass is bad.
Below is a picture of a bad system1 score display. Notice the white corners.
Also if you look close at the (clickable) larger version of this picture,
you can see some of the filament wires are broken!
This glass display tube is junk, and there's no repairing it. Also if the "nipple"
on the back of the display glass if broken, the display is also unrepairable.
A bad system1 or system80 score display glass with white corners and
a broken filament wire (which can be seen if you look closely.)
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Bad display glass boards shouldn't be discarded though, as the chips on these
may still be good. It's best to save the broken display, because you may need
the udn6116 or 7432 (status score display) chips later for another repair.
Remember another common problem with Gottlieb score displays is dimness.
Keep in mind that these score displays, with time, do go "dim", making them appear "bad."
If the corners of the display glass are black, yet the display doesn't work,
it's probably a good time to "recharge" the display as described
here.
What happens is the display anodes oxidize. If a display hasn't been on
for years, often at first the display will show as "dead" or show
very dim. Leaving the game "on" for a bit often fixes this problem.
Or you can "recharge" the displays (see below for details on that.)
Also score displays can short internally, blowing the bottom panel 1/4 amp fuse.
For this reason, when booting a game that has
been sitting for a long time, it's best to turn the game on with just ONE score
display connected (player1.) If the game comes up with that display, power off,
and connect another display, and power back on. Repeat this until all the score
display are connected. This will tell you if any one particular display is a problem.
The display board also has und6116 chips, which can be tested. These chips handle
the display digits. If the chip goes completely dead, the display won't work at all.
If if portions of the udn6116 goes bad, certain digits won't work. These chips can be
tested though. With the power off, disconnect the display and
use a DMM set to diode function:
- Red DMM lead on udn6116 chip ground (pin 9)
- Black DMM lead on udn6116 pin 2 to pin 8 - reading of .5 to .7 should be seen.
- Black DMM lead on udn6116 pin 11 to pin 17 - a null (no reading) should be seen.
Display Data Introduction and What Controls What.
Gottlieb System1 (and System80) blue displays are made by Futaba, and are
a low-voltage (60 volt) score display. Yea I know 60 volts doesn't
sound that low, but compared to the orange 100 volt plasma displays used by Williams
and Bally, the Futaba displays are low voltage. Because the Futabas are low
voltage, they tend to last longer than the high voltage plasma displays.
The displays are controlled by CPU spider chip U6 and a few TTL chips.
The 7-segment decoders Z16,Z17 (7448) control the digits
for the displays. If the displayed numbers look strange
then one of these chips is probably bad.
Chip Z16 controls player 1/2 displays and the credit/ball display, while Z17
handles player 3/4 displays.
For example here's a list of data points and where they go:
| Digit | Display(s) | CPU Connector | CPU Chip/Pin |
|---|
| D1 | Players 1 & 3 | A1J3-9 | z21-3 |
| D2 | Players 1 & 3 | A1J3-8 | z21-6 |
| D3 | Players 1 & 3 | A1J3-6 | z21-8 |
| D4 | Players 1 & 3 | A1J3-7 | z21-11 |
| D5 | Players 1 & 3 | A1J3-17 | z20-3 |
| D6 | Players 1 & 3 | A1J3-16 | z20-6 |
| D7 | Status | A1J3-14 | z20-8 |
| D8 | Status | A1J3-15 | z20-11 |
| |
| D9 | Players 2 & 4 | A1J3-11 | z19-3 |
| D10 | Players 2 & 4 | A1J3-10 | z19-6 |
| D11 | Players 2 & 4 | A1J3-12 | z19-8 |
| D12 | Players 2 & 4 | A1J3-13 | z19-11 |
| D13 | Players 2 & 4 | A1J3-19 | z18-3 |
| D14 | Players 2 & 4 | A1J3-18 | z18-6 |
| |
| D15 | Status | A1J3-20 | z18-8 |
| D16 | Status | A1J3-21 | z18-11 |
Note the 7448 chips aren't shown in the table above. Typically if
these are a problem it effects things differently. Notice in the table above displays
are grouped into displays 1&3 and 2&4. But say displays 1&2 or 3&4 are not working...
This usually means a problem with one of the 7448 chips. For example Z16
works with displays 1&2, where Z17 works with displays 3&4. Also remember
because of the issue with z16/z17 dying by removing a connector with the power on,
suspect these two chips early in the process, as people make the connector
removing mistake a lot.
There is also a circuit that makes number "1" to be shown with an extra eighth
segment in the middle of the digit instead of the usual two right side
segments. This is done with chips Z13/Z14/Z15 on the CPU board. Suspect those if there
are problems in showing number "1".
The displays are multiplexed, meaning
one digit is displayed at a time. This digit selection signals come from CPU chips Z18-Z21.
Finally there is a UDN6116 chip on the display board itself that controls
the digits on the score display.
System1 and System80 Six Digit Displays Interchangable.
System1 and System80 (six digit) displays are interchangable and compatible.
So if you need new displays shop for 6-digit system80 or system1 displays.
The only difference is on system1 display they have a "nipple protector"
on the back of the board which went away for system80.
The Gottlieb System 1 CPU controlled light arrangement.
From actual Gottlieb documents, so it's their property.
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The 6-digit Futaba score display and 4-digit credit/ball display.
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Recharging System1/System80 Score Displays.
The six digit blue Futaba score displays used on System1 and System80
games are identical and interchangable. But often the displays will
fade over time, eventually not working at all. There may not be any
problems with the display circuits themselves, but instead there may be
oxidation on the display glass filament wires. There is a trick
to burn this oxidation off the filament wires, making the displays
work like brand new (there is a limited number of times you can
do this though, the law of diminishing returns does apply).
System1 or system80 six digit score display being "recharged" with 24 volts DC.
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First turn the game off and remove one of the 6-digit score displays. Then take a pair
of jumper wires, and connect them to the front door coin lock-out coil lugs (24 volts DC).
Next attach the alligator clips to the outside most pins of the score display
(it does not matter which gets ground). Now turn the game on for 3 to 5 seconds,
then immediately turn the game off. While the game is on,
the thin horizontal filament wires in the score display glass will glow.
This burns the oxidation off the filament wires.
WARNING: Do not leave the power to the display for more than
5 seconds, or you could burn a filament wire ruining the display!
Also do not use coil voltage to recharge the 4-digit ball/credit display.
If you need to recharge a 4-digit ball/credit display, use 8 to 12 volts DC
instead. I have even heard of some people using a 9 volt battery to do this.
Two Different 6 Digit Display Driver Chips.
The Gottlieb system1 (and system80) display glass boards can
have two different sets of driver chips. The most common variant
uses two udn6116 high voltage display driver chips. There is also
another variant that uses two Dionics DI513 chips. If you have a
choice, go with the udn6116 variant, as the 6116 chips are available
(though expensive.) The Dionics DI513 chips are really hard to find,
making this type of score display board harder to repair.
Top: a bad system1 display glass using the Dionics DI513 chip set.
Bottom: a good system1 display glass using the more common udn6116 chips.
Note the corners of these two glasses - the bottom glass had black corners
(which is good), and the top bad glass had white corners (which is bad,
this glass is junk.)
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Protect the Nipples.
System1 and system80 score glasses have "nipples" on the back side
of the display glass. If this nipple breaks, the glass is useless
(there's no repairing this.) Most system1 games have a black plastic
cover protecting the nipple from breakage. But later system1 and system80
games are missing this cover. If you're generally an protective person,
it's not a bad idea to protect the glass nipples. I use a nylon wire bundle tie,
put it over the nipple, and fill the area with silicon. This way if the
display is mis-handled, chances are good the nipple won't break.
A system1 or system80 display glass with an unprotected nipple.
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A system1 or system80 display glass with a modified and protected nipple.
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3h. DIP switch settings.
There are three banks of eight DIP switches on the CPU board.
They are used to set game pricing and other game parameters.
These switches are consistent for all system1 games.
The first eight switches control play pricing. There are four switches
for each coin slot, so that the switches 1-4 control left side
and switches 5-8 the right side coin slot. The other two
DIP switch banks control game options.
My suggestion is to set the CPU board DIP switch as follows
to make repairing the game easier. After you have the game
working, set the switches as desired.
- DIP 1-8=all off (one coin, one credit). Another common setting is to make
switches 1=on (and sw 2-8=off) for 1 coin 9 credits.
- DIP 9=on (three balls/game, off=5 balls/game).
- DIP 10=on (match feature on).
- DIP 11=on (replay instead of extra ball, off=extra ball).
- DIP 12=on (tilt kills current ball only, off=tilt kills game).
- DIP 13=on (show number of credits).
- DIP 14=on (play a tune when game started).
- DIP 15,16 not used.
- DIP 17,18=on (maximum credits 15).
- DIP 19=on (make coin chute 1 & 2 the same coin value, important to be "on" if
using the 1 coin 9 credit option).
- DIP 20=on (chimes/tones when scoring).
- DIP 21=on (show high score to date).
- DIP 22=on (award 3 credits when high score beat).
- DIP 23=on (play a tune when money inserted).
- DIP 24 not used.
Having the switches in these positions will
make troubleshooting a bit easier and consistent from board to board.
3i. Free Play Option.
When checking out the dip switches on a System1 machine,
there is no provision for free play on these games. The best
that can be done via the dip switches is getting nine credits per coin (or 18
credits on the center coin chute), and
setting the maximum credits to 25. But there are some solutions without drilling
the coin door for a credit switch, or having to put quarters in your game.
Bottom board of a System1 game, showing the diode strip.
Pic thanks to PaPinball.com
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3j. Backbox & Playfield General Illumination.
Unlike most other pinball makers, general illumination lights (non-CPU controlled)
are not a big problem in Gottlieb System1 games.
The Gottlieb System1 T (Tilt) and Q (Game Over) relays.
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If the backbox or playfield illumination is always off,
of course first check the fuses on the cabinet bottom board.
The playfield lights are controlled by the T (tilt) relay, mounted on playfield underside.
This relay should not be energized when the game is in "game over"
mode. This relay only pulls in when game is tilted during game play.
There's one set of Normally Closed contact points to turn off playfield lights
in Tilt mode, and another pair to disable flippers, bumpers and slingshots.
The other relay Q is the Game Over relay. It pulls in during game play and bookkeeping.
It enables power to the playfield solenoids and flipper. The backbox "Game Over" and
"Match" lights are also controlled by the Q relay. The third NC (normally closed) switch on this relay
is a bit of a mystery - it disconnects the tilts switches
in game over. Don't know why, maybe just a quick fix for
a software problem? Or a trick to prevent players testing the sensitivity
of tilt before starting a game? (more likely.)
3k. Sound board problems.
System1 Sounds.
In the three first System1 games there was a three tone chime unit, as used in
Gottlieb's EM games. With Close Encounters this changed to a simple tone generator
sound board, which still used the same three driver board transistors to
generate sound. This sound board was located in the lower cabinet right
next to the knocker (where the chime box was previously mounted).
The Gottlieb System1 first generation 3-tone sound board (Close Encounters).
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The Gottlieb System1 first generation 3-tone sound board (Close Encounters).
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Sound improvement came with Totem, when a microprocessor controlled
sound board replaced the earlier 3-tone sound board. Both the chime box or the sound
boards were located in the same place, in the right side of lower cabinet.
The new sound board as used on Totem and later games (multi-mode sound),
though having more sound bites, was not really a big sound
improvement for the System1. It had a switch that changed the sound format,
much like Williams did. It also used a now unavailable Rockwell chip R3272-12.
It still used the same three driver transistors from the
driver board, but not in unison (as Williams and Bally did to control more than
three different tones). Instead Gottlieb's MPU controlled sound board randomly
picked the different sounds to play. This caused some player confusion, because
a 10 point switch could have any number of different sounds.
The Gottlieb System1 second generation sound board.
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Generation2 Sound board Ground Problems.
The +5 volts for the second generation sound board comes from an onboard
7805 regulator (center top of board) on games Totem and later. The ground connection
is from two zinc plated mounting screws. These screws can corrode,
causing the ground connection to be intermittent. Worse,
the regulator output voltage can rise to +12 volts because
of this bad ground.
This can, of course, ruin the logic chips, and often the 6530 RIOT
chip. The 6530 RIOT (RAM, input, output, timing) chip is no
longer available and very hard and to find and expensive.
And since the 6530 contains masked ROM code, it is unique
for this board.
So it is important to check and clean the 7805 regulator
mounting hardware. Put some grease on the surfaces before
reassembling, to prevent moisture causing any corrosion and blowing
up the hard to get parts.
The Gottlieb System1 chimebox.
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Substituting Chimes for the Sound Card.
Because of the sound card problems listed above,
many operators take out the MPU controlled sound board and replace
it with an older chime unit. Most players find this far more pleasing and
consistent to the ear. All system1 games are downward compatible to chime coils.
Be sure to use chime coils 12 ohms or greater.
If coils with less resistance than 12 ohms are used, the
driver board transistors Q26,Q27,Q28 will fail. If adapting a chime box from a
Bally game, that should work fine as 50 volt chime coils will
have higher resistance. Also don't forget to add 1N4004 diodes to the
chime coil lugs, with the coil's power lug connecting to the banded side of the diode.
- Mount the chime box right next to the knocker coil in the lower cabinet side panel near
the game's power switch.
- Route the 25 volt power from the adjacent knocker coil lug
(banded diode lug), which is right next to the existing sound board
(and the newly mounted chime box).
- "Daisy chain" the 25 volt DC coil power to all three chime coils'
banded diode coil lugs.
- Now move the following wires from the sound board connector to the chime box
coils' non-banded diode coil lugs:
- orange/black/black wire goes to the 10 point chime coil lug.
- red/brown/yellow wire goes to the 100 point chime coil lug.
- red/green/green wire goes to the 1000 point chime coil lug.
Remove the sound board from the game.
The Gottlieb System1 chimebox, another angle. The red wire is power,
coming from the knocker coil. Orange/blk/blk (left) is the 10 point chime.
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3L. Flippers, RotoTargets, Etc.
The flipers used in Gottlieb system1 games don't differ a lot from
the flipper used in Gottlieb's 1976 to 1979 Electro Mechanical (EM) games.
The major difference is Gottlieb used DC voltage on all system1 flippers,
where AC was mostly used in the EM era (though some late EM Gottliebs
did have DC flippers.) This style of flipper is extremely robust, and does
not require a lot of work to make strong and snappy. Though many say the
feel of these system1 flippers is "clunky", that is largely due to the
over-engineering of the design. This means less maintenance down the road,
but a heavier flipper feel during play. Keeping the mechanism clean
goes a long way with these flippers.
The flipper coils used are serial wond style - basically two flipper coils
in a single package. This is typical of all flipper designs by Gottlieb.
There is a high power side which does the initial flip of the ball, an EOS
switch (End of Stroke), and a hold side of the coil which allows the player
to hold the flipper "up" without burning the coil. A single 1n4004 diode is used
to prevent coil collapse voltage from flowing back to ruining the AC to DC bridge
rectifier.
The major difference between Gottlieb EM, System 1, and System 80
flipper assemblies is the actual flipper coil used. EM games with AC power
used A-5141 coils (no diode), while System 1 games (DC power) used a A-17875 coil
with one 1n4004 diode. (Note some System 80/80A/80B games used A-17875 coils,
but with Black Hole often the A-20095 "super flipper" coil was used.)
An intermediate strength flipper coil A-24161 was sometimes seen too,
starting with System 80A games.
Late EM and system1 three inch flipper assembly. This picture is actually
from a Gottlieb Jacks Open EM, but it's the same assembly as used on system1 games.
Note the nylon "finger" that comes out of the top of the flipper assembly.
Some people cut this finger off, as it can cause some additional friction.
(Gottlieb in fact did this on late system1 games.) Personally I feel if the
assembly is clean, there is no need to cut off the finger.
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The Flipper EOS Switch.
Since a flipper coil is actually two coils in a single package, the
initial power side of the coil is "turned off" by the EOS (end of stroke)
switch. This switch is normally closed, shorting out the low power
side of the flipper coil. When the flipper is at "end of stroke" (fully engaged),
the EOS switch opens, putting both the power and hold coils in series.
This allows the player to hold the flipper button, keeping the flipper "up",
and not burning the coil.
Remember that lower resistance means more power. But this also means more
heat and more current draw. So the idea is to have a second "hold" part of
the flipper coil, which is high resistance (and low power) in series with
the power side of the coil, to decrease power consumption and heat when the
flipper is kept energized. As a comparison,
the high power side of the flipper coil is about 2 ohms. The hold side of
the flipper coil is about 40 ohms (or 42 ohms when in series with the power side.)
With this in mind, it's important to have a working EOS switch! If the switch is
mis-adjusted and never opens, the hold side of the flipper coil will never engage,
and the coil will burn rather quickly. On the other hand if the EOS switch is dirty,
burnt or broken, and is never really closed, the flipper will be very weak.
Because of these issues with EOS switches, they are by far the biggest problem
with flippers.
Another link in the chain is the cabinet flipper switches. These are player controlled,
but they too can have problems (breakage, dirty, mis-adjusted.) The cabinet flipper
switches complete the flipper power path to ground, so if they have problems,
weak or non-working flippers result.
System1 Flipper Parts.
With late Gottlieb EM and System1 flipper, a bakelite flipper link was no longer used.
Instead Gottlieb went to nylon plastic parts on the coil plunger.
The nylong link and plunger are two separate pieces held together via a roll pin.
Two nylong (upper and lower) flipper bushing or bearings are used, and the flipper
shaft goes through these. This design is unique to Gottlieb, and it's why their
system1 flipper have that certain "tank like" robust feel.
(The actually weight of all these parts is greater than say Williams flipper
parts, giving the flipper this "thick" Gottlieb flipper feel.)
A plastic triangular actuator is used to open the EOS switch, thus turning on
the "hold" side of the flipper coil.
The only major weakness to this design is how the EOS switch is actuated - the
EOS switch is opened via the flipper crank / pawl assembly, and it's a metal-on-metal
contact point. As we all know, metal to metal provides a good wear point, and
this is something that should be evaluated on every Gottlieb system1 flipper.
The flipper crank can wear a hole in the EOS switch blade.
(Gottlieb did fix this issue in the late 1980s around during production of the
system80 TX-Sector game.) Frankly I personally have not seen many worn EOS blades
on system1 games (30+ years after they were made), so this isn't a huge issue.
The only system1 flipper design change was a different flipper link on 3" flippers.
The molded plastic flipper link used on earlier System 1 games had a
"finger", which protruded through a hole
in the bearing bracket. The finger was used to center the motion of the flipper plunger.
But the flippers wear with age, the finger can drag a bit through the hole.
This can cause a slightly less powerful flipper. For this reason,
some people cut or grind the finger off the link. Personally I feel if all
the other parts (the nylon bushings/bearings) are in good shape, this is
not necessary.
Not on some System 1 games, such as Joker Poker, Count-Down, and
Genie, ther are also 2" flippers. The 2" System1 flipper design is the same
mechanism as Gottlieb EM games, using a standard plunger and bakelit link.
(The flipper coils are different too, with system1 using an A-17875 coil.)
Weak Flippers.
The most common complaint in any pinball machine is weak flippers.
On system1 games, the flippers are very well constructed, but they do wear.
The single biggest cause of weak flippers are dirty or mis-adjusted
EOS (end of stroke) switches on the flipper assemblies.
Also dirty cabinet flipper switches. These are high current tungsten
switches, and can be re-faced with a file. (They are NOT switch matrix
switches.)
The flipper EOS switches should open about 1/8" when the
flipper is at full stroke. Any less of a gap, and the flipper coil
may never engage the low power side of the coil, burning the flipper
coil. If the EOS switch gap is too great, flipper strength is compromised.
Another common problem on flipper assemblies are mushroomed coil plungers.
The metal plunger, which slams into the coil stop with every flipper plunge,
takes a lot of abuse. The plungers can be removed and the mushroomed end
filed smooth. Also replacing the flipper coil sleeve is a very good idea.
Right side System1 flipper.
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Left side System1 flipper.
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Roto-Target from Close Encounters.
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Roto-Target from Close Encounters.
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Gottlieb Rubber Sizes.
Gottlieb lists rubber part numbers in their manuals, but does not indicate the
actually sizes and types of rubber. So below is a list of the rubber parts and
sizes.
| Part# | Rubber Type |
|---|
| #E-15 | Rubber Tip |
| #986 | Rubber grommet - drop target |
| #1872 | Rubber plunger tip |
| #2752 | Rubber grommet - chime |
| A-1344 | Rubber rebound |
| A-5240 | Rubber grommet |
| A-10217 | Rubber ring 3/8" |
| A-10218 | Rubber ring 3/4" |
| A-10219 | Rubber ring 1" |
| A-10220 | Rubber ring 1-1/2" |
| A-10221 | Rubber ring 2" |
| A-10222 | Rubber ring 2-1/2" |
| A-10223 | Rubber ring 3" |
| A-10224 | Rubber ring 3-1/2" |
| A-10225 | Rubber ring 4" |
| A-10226 | Rubber ring 5" |
| A-13149 | Flat beaded rubber ring - 2" small flipper, red |
| A-13151 | Rubber ring - 3" flipper, red |
| A-14793 | Rubber ring - mini post, 23/64" |
| A-15705 | Rubber ring - mini post, 27/64" |
| A-17493 | Rubber ring 7/16" |
Gottlieb Wire Colors.
Gottlieb had a unique situation where they owned an actual wire color
line striper. That is, they could buy white wire, run it through their
wire striper machine, and get up to three colors striped on the wire.
A pretty cool machine that worked great for PVC plastic coated wire.
Anyway, Gottlieb used a system of three colors for their wires, and each
color has a number associated with it. So a wire that is coded 012 means
it's a white wire with a black, brown and red trace. All wires are coded
like this except for the ground wires, which are green plastic with a yellow
strip (color 54.)
Gottlieb Wire Colors Decoded
| Color |
Code# |
| Black |
------ |
0 |
| Brown |
------ |
1 |
| Red |
------ |
2 |
| Orange |
------ |
3 |
| Yellow |
------ |
4 |
| Green |
------ |
5 |
| Blue |
------ |
6 |
| Purple |
------ |
7 |
| Grey |
------ |
8 |
| White |
------ |
9 |
3m. The Curious Case of Pinball Pool.
Gottlieb's system1 game "Pinball Pool" is essentially a reissue of
their very successful 1973 EM game "Hot Shot" and "Big Shot" (four
versus two players, respectively.) Gottlieb did update the new
Pinball Pool a bit though with a center captive ball, and two
upper side kick out holes (which scores the bonus and resets
the drop targets, after they are all knocked down.)
The system1 flavor of this game is quite good. In fact, it's probably
better in a lot of ways than the original. One way that it's different
is related to the fourteen drop targets; they can be set (using a
separate 3 or 5 ball under-the-playfield plug) to drop adjacent targets.
That is, if the game is set to 3 balls, hitting the left side "1" drop
target will also automatically drop the right side "15" drop target.
And if the right side "14" drop target is hit, the corresponding
left "2" drop target will fall. Note if the game is set to 5 balls,
then only every other left targets 1,3,5,7 will drop their corresponding right
15,13,11,9 targets, and targets 2,4,6 and 14,12,10 are independent.
What is unique is the drop target change between 3 and 5 balls isn't a CPU board DIP
switch, but is instead an under the playfield plug. So when changing the game
from 3 to 5 balls on the CPU board, the under playfield plug should also
be changed (assuming you want the drop target rules to follow the ball number change.)
The under-playfield drop target adjustment plug for 3 or 5 balls per game on Pinball Pool.
But wait, we're not done. In order for the game to do the unison drop target
falls, Gottlieb uses a "pancake" coil (A-19217) on the drop target assemblies.
Each and every drop target on the Pinball Pool has one of these drop target trip coils,
which allows any drop target to be automatically "dropped" (without a ball hit.)
So that's 14 additional coils in a Pinball Pool that other Gottlieb system1 games
do not have.
Each drop target has a "pancake" coil (A-19217, red arrow) to allow auto drop target falls.
So this begs the question, how does Gottlieb control 14 trip coils when their driver
board can barely control eight coils (including the three chime coils/sound drivers,
knocker coil, outhole coil, game over and tilt relays, plus two drop target reset coil pairs
and the unique "B" relay), without using under-playfield mounted transistors?
(Note there's already one under playfield mounted transistor on Pinball Pool,
for the drop target reset bank coils.) It's an interesting question.
How would Gottlieb do this without additional hardware and software control? Well
the answer is a bit odd - they do it via mechanical switches and an added "B" relay.
Check out the picture above and notice the switches used on the drop target
assembly (blue arrow.) For example when the "15" drop target falls, the above
switch (blue arrow) momentarily closes. This switch then closes the power circuit
to the "1" drop target coil, causing that target to fall automatically when it's
partner (the "15" target) falls. The under-playfield plug adjustment connects
all right and left drop targets in pairs (if set to 3 ball). If the plug is set
to 5 ball, every other drop target is wired in pairs.
The "B" relay, which is unique to Pinball Pool, and cuts power to the drop target trip coils.
But what happens when the drop target banks are reset at game/player/ball start?
This is where the added "B" relay comes into play. When the game needs to reset
the drop targets, the "B" relay pulls in. This opens the lone normally closed switch
on the relay, turning off the power to the 14 drop target trip coils. If this didn't
happen when the target banks were reset, it would also automatically cause some of
the drop targets to fall via the drop target coils.
The schematics for the drop target trip coils on Pinball Pool,
and how they are wired to the adjacent drop target momentary switch.
Notice the normally closed "B" relay switch in the circuit amd the
3/5 ball adjustment under-playfield switch.
So what does this all mean? Well if you smell a coil burning during game play,
it could be one of the drop target trip coils baking. This is easy to do if one of
the drop target switches are adjusted closed (see picture above, blue arrow.)
Or if none of the drop targets fall automatically in unison, that could be the
lone "B" relay switch is mis-adjusted. Keep these things in mind when working
on a system1 Gottlieb Pinball Pool.
3n. Miscellaneous Problems and Fixes
Problem: Can't add more than one credit to the game,
or bookkeeping memory appears to be blanked, or
replay scores cannot be set.
Answer:
Replay scores and bookkeeping values are stored in the CMOS RAM on the CPU board at Z22.
Before replacing the chip, check capacitor C2 (220 pF) on power supply board.
A bad C2 cap can cause noise in
+5V supply voltage, which prevents the Z22 RAM from working. Also
replacing C24 (0.01 uF) on CPU board is a good idea, which is the buffer cap to the RAM.
Problem: Game goes to "GAME OVER" during play for no apparent reason.
Answer: Check the two normally closed SLAM switches for adequate pressure.
One of the slam switches is mounted inside the coin door, the other is at
the ball roll assembly inside the cabinet.
Improperly adjusted switches will respond to game vibration levels and show this problem.
Also check the suppression diodes across the pop bumpers, flippers and slingshot
kicker coils. An open or broken diode/older connection can cause random game-over
symptoms.
Problem:
On a Genie I have a display problem: the 1000s digit on player 1 & 3
slightly glow and makes it hard to read the proper number. I also noticed
that when a game is started and you have the flashing "0" for the player 1,
then the 1000s digit will also light up the same as the credit display.
Answer:
The Z21 (7408) chip on the CPU board was bad.
Problem: While resetting the score levels stored in memory,
holding the credit button in fails to increment the score setting.
Answer: This problem and others which may occur while
adjusting score levels can be prevented by ensuring that all drop targets
are reset before attempting to adjust the score levels.
Problem: My game does strange things.
Answer: Unusual or erratic behavior, especially after game has been on
for long time, may be caused by overheating game PROM Z23 on the CPU board.
This bipolar PROM gets quite hot, and can cause
a game to do very strange things. Try
attaching a small heat sink to the PROM with some superglue. Since the game
PROMs are hard to find, it is also a good idea to lengthen its
life even if you dont have problems. It seems that some PROM
chips are more sensitive to heat than others. Alternatively replace
the game PROM with a 2716 EPROM adaptor board.
Problem: Coils or driver board transistors get very hot.
Answer: Gottlieb System 1 games suffer from grounding problems.
The solenoid ground can rise above logic ground, causing driver transistors
to conduct continuously.
Solenoids may work but get stuck or overheat. To fix this, make sure you have
done all the mandatory ground modifications outlined in this document.
Problem: Game starts, gives ball to shooter and freezes.
Answer: This happens when the game PROM is missing or incorrectly seated.
Also check resistors R122-R131.
Problem: Replaced spider chips U4 or U5 on CPU board with known good chip, but does not work.
Answer: These two chips contain the game operating system ROM,
and must be of the same revision. The revision levels that work together are:
- U4 A1753-CC works with U5 A1752-CD
- U4 A1753-CE works with U5 A1752-CF
- U4 A1753-EE works with U5 A1752-EF
Problem: Buck Rogers "thinks" it needs to score. Start a game, and it continuously
increments the 100s count score. The ball is
ejected, and the game starts counting up points. There are times when
this doesn't happen. But when the first score is made, i.e., the ball
going over a switch, then the scoring just keeps on going. Makes
for an intersting ball, but makes the game useless.
Check ALL switch matrix inputs with a logic probe for a stuck switch, and NO switch
matrix inputs are sending anything to the MPU to tell it to start scoring.
Checked the output of the inverters (Z9 and Z28) to see if one
of them is sending something to U5. The inverters are working fine.
Answer: the game PROM chip was bad. Replaced it with a known good
game PROM and now the game and CPU board work fine. Was able to clean the
legs on the old PROM and reinstalled, finding that it now worked too.
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