3a. When things don't work: Replacing Components.
After finding a bad component, replace it! Transistors,
bridge rectifiers, and most chips are not socketed. They are soldered directly into the
driver board. Care must be taken when replacing a bad component.
See http://marvin3m.com/begin
for details on the basic electronics skills and
tools needed for replacing circuit board components.
When replacing components, the object is to subject the board to the least amount of
heat as possible. Too much heat can lift or crack the board's traces. Too little heat and
the plated-through holes can be ripped out when removing the part. ircuit boards are
too expensive to replace. So be careful when doing this.
To remove a bad component, just CUT it off of the board, leaving as much of its original
lead(s) as possible. Then using needle nose pliers, grab the lead in the board while
heating the lead (and not the circuit board!) with the soldering iron. When the solder
liquifies, pull the lead out. Clean up the solder left behind with a desoldering tool.
When replacing chips, always install a socket. Buy good quality sockets.
A good machine pin socket is desirable. Avoid "Scanbe"
sockets at all costs!
When Replacing Bad Driver Transistors...
ALWAYS check the coil mounted diode too! Often the coil mounted diode will break, causing the
driving transitor to fail. If the diode is not replaced also, the driving transistor
will fail again and again. This is often overlooked in DataEast/Sega games.
3b. When things don't work: Coil & Flashlamp Problems
(Checking/Fixing Transistors and Coils)
If a coil is "stuck on" when the game is turned on, a shorted driver transistor
is often the cause. If a coil does not work (and the fuses are good!),
an open driver transistor could be the cause. This section will help
diagnose this, and other related faults.
What do the Driver Transistors Do?
Basically, a driver transistors completes each coil's path to
ground. There is power at each coil, all the time. The driving
transitor is "turned on" by the game's software, through a TTL (Transistor to
Transistor Logic) chip. When the transistor is turned on, this completes
the coil's power path to ground, energizing the coil.
Driver transistors also work the CPU controlled lamps and flash lamps,
causing a lamp to "lock on".
Sometimes these driver transistors short "on" internally. This completes
a coil or flash lamp's power path to ground permanently, making it "stuck on",
as soon as the game is turned on. Also a shorted pre-driver transistor,
or shorted TTL chip (which controls the transistors) could be the problem
(though a shorted driver transistor is the most common cause). To fix
this, the defective component (and perhaps some other not defective,
but over stressed componets) will need to be replaced.
Driver Transistor Operation.
As described above, the main driver transistor (a TIP122/TIP102 or TIP36) completes
the coil or flash lamp's power path the ground, energizing it. But there are other
components involved too!
Each driver transistor has a "pre-driver" transistor.
In the case of a TIP122/TIP102 (the most common driver transistor), this is a
smaller 2N4401 transistor.
If the main driver transistor is a TIP36c, this is pre-driven by both
a TIP122/TIP102 and a smaller 2N4401 transistor. The bigger TIP36c
transistor is an even more robust than the TIP122/TIP102, and controls
very high powered, high use coils (like the up kickers).
Then before even the smaller 2N4401 pre-driver transistor,
there is a TTL (Transistor to Transistor Logic) 7408/7402 chip.
And prior to this is the 6821 PIA (this is really the
first link in the chain). This is what in affect turns on the smaller 2N4401 pre-driver
transistor, which then turns on the TIP122/TIP102 (which then turns on the TIP36c, if
used for the coil/flash lamp in question), and energized the device.
- 5F - PIA1 solenoid read/write $2100
- 11D - PIA2 lamp read/write $2402
- 11B - PIA3 display2 read/write $2802
- 9B - PIA4 display1 read/write $2C02
- 8H - PIA5 switch read/write $3002
- 7B - PIA6 sound read/write $3402
This series of smaller to bigger transistors is done to isolate the hi-powered
coil voltage, from the low-power logic (5 volts) on the driver board.
Also the 7408/7402 chip and PIA (all operating at +5 volts),
which really controls the transistors,
can not directly drive a high power TIP122/TIP102 or TIP36c transistor
(which is controlling the coil's high voltage by sinking the ground).
If ANY of these components in the chain have failed, a coil/flashlamp can be stuck on, and will
energize as soon as the game is powered on!
I have a Stuck-on Coil (or Flashlamp), What should I Replace?
A short summary (before reading all the info below).
The following procedures will test the driver and pre-driver transistors in
question. If either is bad, it will need to be replaced. When replacing either
a driver or pre-driver transistor, replace them both (or in the case of a
TIP36, replace the TIP122/TIP102 and smaller 2N4401 transistor)!
A shorted transistor will cause the other transistors in the link to be
stressed, and they should all be replaced. Also be sure to test the
coil's resistance with a DMM and replace the coil if needed. If this
is not done, powering the game on with a low-resistance coil will
fry the newly installed CPU board components.
Inside the front cover of the game manual is a list of each coil used
in the game. Also listed are the driving transistor(s) for each coil.
Use this chart to determine which transistors could potentially be bad.
Also use the schematics.
Before changing any transistors/chips on the CPU board, always check
the coil in question for proper resistance. If a coil has low
resistance (below 3 ohms), powering the game on with new
driver transistors will destroy these components. Use a DMM set
to ohms and check (all) coils. Anything below 3 ohms should be
replaced.
If after replacing the driver transistors the coil/flashlamp is still
stuck on, then replace the TTL 7402/7408 logic chip. The TTL chip can
also go bad. If there is still a problem,
the 6821 PIA behind the TTL chip can also fail.
Also remember to test the resistance of a coil after replacing
the driver transistors. If a coil gets hot, it can burn the painted
enamel insulation off the coil windings. This lowers the overall resistance
of the coil because adjacent windings short together.
If resistance gets much below 3 ohms, the coil becomes
a "short", and will fry its associated driver transistors very quickly!
A Coil just Does Not Work - What is Wrong?
Driver transistors can go "open" too. This means all the logic prior
to the open transistor could be working fine, but the coil will not
energize. If there is power at the coil, this is something to consider
(but first see the test procedures below to make sure the coil itself
is actually OK).
Do the Transistor Test Procedures work 100%?
In short, no. But they do work about 98% of the time, and are an
excellent starting point. But yes, a transistor can test as "good",
but still be bad. The DMM test procedures test the transistors with
no load. Under load, a transistor could not work.
Required Documentation.
When repairing transistors and coils, the game manual will be needed. There are several
sections that are very useful for repair. First is the
page in the "Flash Lamp/Coil Test" section, "Game Diagnostics" chapter
(pictured above in the the Circuit Boards and How They Work section).
The second diagnostic tool is in the "yellow pages" section;
the schematics labeled "Playfield Coil/Flash Lamp Wiring Diagram".
The last schematic is again in the "yellow pages", and is labeled
"Playfield Special Coil Diagram". These tools
show which transistors control which coils/flashlamps. Without this
information, fixing bad coils/transistors is much more difficult.
In case there is no manual available, look at the coil's wires. One is
the power wire (connecting to the coil's lug with the banded side of
the diode), and the other is the smaller wire going to ground via the driver board.
Note the color of this wire (for example, blue with a yellow trace).
Now go to the driver board and examine the connectors for this wire
color. It may take some digging, but you'll find it. Write down the
connector number and pin number where the wire goes. Remove the connector
and use a DMM set to continuity, and find the TIP transistor that connects
to that connector pin.
DataEast Transistor Types.
There are several types of transistors used on the DataEast/Sega CPU and PPB boards:
- TIP122: used at Q39-Q46 (multiplexed),
Q8-Q13 (special coils), Q23-Q30 (constant power), Q72-Q79 (lamp matrix
row returns) on the CPU board. When replacing a TIP122,
always replace a TIP122 with a TIP102 instead.
The TIP102 is a more robust version of the TIP122.
Equivalent transistors for TIP122 = NTE261; TIP102 = NTE2343.
- TIP36c: used at Q1-Q5 on the PPB board
(if the game is Laser War or Secret Service, it does not have
this board, and hence does not have any TIP36c transistors).
These transistors control the high voltage 50 volt coils that
were previously controlled by under-the-playfield SMIG relay boards. NTE393 is an equivalent transistor.
- 2N4401: used at Q2-Q7, Q15-Q22, Q31-Q38 on the CPU board.
Functions as a pre-driver for the TIP122 transistors.
NTE123AP is an equivalent transistor.
- 2N5060: used at Q81-Q88 on the CPU board. Acts as a pre-driver for the TIP122
transistors in the lamp matrix rows (lamp returns).
NTE5400 is an equivalent transistor.
- TIP42: used at Q64-Q71 on the CPU board. Controls the lamp matrix columns (lamp drive).
The TIP42 strobes the 18 volts for any particular lamp column.
NTE197 is an equivalent transistor.
- 2N6427: used at Q56-Q63 on the CPU board. A pre-driver for the TIP42 transistors in
the switch matrix columns (switch drive). NTE46 is an equivalent transistor.
- 2N3904: used at Q48-Q55 on the CPU board. Controls the switch matrix columns (switch drive).
NTE123AP is an equivalent transistor (which is
the same equivalent as the above mentioned 2N4401).
- P20N10L: used for magnet boards on games like Last Action Hero
and Guns and Roses. A recommended replacement would be IRL540.
Stern WhiteStar Transistors.
Later "Whitestar" games used MOSFETs instead of TIP darlington transistors:
- 12N10L - 100 volts, 12 amps continous. Exactly the same
as the IRL530 (Gottlieb uses the more generic 12N10L nominclature).
- 20N10L - 20N10L replaces either an IRL530/IRL540 or a 12N10L, but not vice-versa.
20N10L MOSFETs have been discontinued. The replacement is a 22NE10L, which
is an enhanced version that can sink 10% more current (22 amp versus 20 amps).
The 20N10L was used in Pinball 2000 and many Whitestar driver boards and under PF magnet board.
- IRL530 - 100 volts, 12 amps continuous.
Aka NTE2987. Some people call it IRF530, but that is actually a
different animal. The "L" in "IRL" means logic level drive, which
is an important aspect of this MOSfet. There is also an advanced
- IRL540 - 100 volts, 36 amps continuous, so this is a bit more
robust than a 20N10L. You can replace the 20N10L or 22NE10L with an IRL540.
The "IR" in the above part numbers means International Rectifier
company. The "L" after the "IR" means logic level drive. International
Rectifier had their own MOSfet numbering system like the IRL530 and
IRL540. The generic part number are 12N10L and 20N10L.
The first pair of numbers refers to the current rating.
In the case of a 20N10L, it is rated at a maximum drain current of 20 amps.
The N indicates an "N channel" FET. Some FETs are of opposite polarity
and known as "P channel" FETs.
The final two numbers indicate the voltage rating, where "10" means
100 volts. The "L" suffix indicates that a logic level
can be used to turn the FET on.
Note you cannot substitute an IRF Mosfet for an IRL Mosfet.
The IRF Mosfet has a higher Vgs threshold voltage. The IRF's Vgs voltage is
higher than the guaranteed output high voltage of a typical logic gate - it
is intended to have a higher gate voltage to turn it on.
The IRL (L = Logic Level Gate Voltage) is designed to turn on the MOSfet using the
output high (5 volts) of a typical logic gate.
Coin Door Interlock Switch - IMPORTANT!
Starting with WWF Royal Rumble, DataEast added a coin door
interlock switch. When the coin door is open, this switch opens,
and cuts the +32 volt and +50 volt power directly from the transformer.
DataEast did this for good reason; it helps prevent an accidental
short of the solenoid voltage to a lamp socket, switch lug, or other component.
This prevents possible damage to the CPU board when working under
the playfield with the power on.
When testing coils on games WWF Royal Rumble and later, make
sure the coin door is shut. If the door is open, no coils will
work in the game!
Interestingly, if while playing a game the coin door opens,
and the cabinet flipper button is pressed,
the flipper will stay energized! This happens because the 9 volt
solidstate flipper hold circuit for the flippers is not
interrupted when opening the coin door.
When Replacing Bad Driver Transistors...
ALWAYS check the coil mounted diode too! Often the coil mounted diode will break, causing the
driving transitor to fail. If the diode is not replaced also, the driving transistor
will fail again and again. This is often overlooked in DataEast/Sega games.
The Bank Selected Solenoids.
On all DataEast/Sega games,
transistor Q29 on the CPU board controls the "solenoid L/R select relay" on the PPB board.
This is the relay that controls which bank (either "L" or "R", or
sometimes labeled "A" or "B" a la Williams) that transistors Q39-Q46
control. This means one transistor can control two different
devices (usually a flasher on bank R, and a solenoid on bank L).
First Test the Solenoid L/R Select Relay!
When the solenoid A/C select relay is not working correctly,
there can be all kinds of coil problems. A malfunctioning
L/R relay, if stuck on or off, won't give any power
to either the coils or flashlamps. If the relay is constantly energized (stuck on bank "R"),
it's probably because it's driver transistor Q29
is shorted on.
On most DataEast/Sega games, the "L" (or "A") bank was for
coils, and the "R" (or "B") bank is for flashlamps.
But on games from Time Machine to the Simpsons, this logic
was reversed. In these games the "L" bank was used for flashlamps
(instead of coils), and the "R" bank was used for coils (instead of flashlamps).
Keep this in mind when diagnosing problems.
The first thing to do is to test the solenoid L/R select
relay. Turn the game on, and enter diagnostics
(entering diagnostics should de-energize the L/R relay; on
some games the L/R relay will stay energized after finishing a game
because of an after-game flasher light show).
Take an alligator test wire
and connect it to the metal tab on transistor Q29. Then with the game on and
in attract or diagnostic mode, touch the other end of the
alligator clip to the ground strap in the backbox (WWF Royal
Rumble and later, make sure the coin door is closed). The
L/R select relay on the PPB board should click "on and off"; it
will click on when the transistor is grounded, and off when not.
Another way to test the L/R relay is find the 1N4004 diode
next to the L/R relay. This is the blocking diode for the relay.
If the Non-Banded side of this diode is grounded using an
alligator test lead, this will also energize the relay.
On games with PPB boards, remember the L/R relay is mounted
on this board (and its diode is right next to the relay).
On the first two DE games that don't have a PPB board
(Laser Wars and Secret Service), the L/R relay (if the
games have one, I'm not sure!) would be mounted under the playfield.
If the relay "click" is not heard, do a quick test of
transistor Q29 using a DMM:
- Turn the game off.
- Put the DMM on ohms (buzz tone).
- Put one lead on the ground strap in the backbox.
- Touch the other lead to the metal tab on transistor Q29.
- If the DMM shows zero ohms (buzz), the transistor is bad! (shorted on).
This bad transistor will cause the L/R relay to stay energized.
The Q29 transistor can stay grounded for a period of
time. This will not ruin the transistor or the relay. Do not
leave Q29 grounded for more than a few minutes. That should be
plenty of time to test any coils.
If for some reason the L/R relay itself is bad, it can be replaced at
mouser.com part number 653-LY2-0-DC24
(NTE equivalent is R14-11D10-24P).
Low Coil Voltage.
Another problem is that the L/R relay can have pitted contacts
on its switches. This can cause some resistance, and lower
the coil voltage. If testing the coil voltage at the coils
shows less than 50 volts or 25 volts DC (depending which voltage
the coil uses), the L/R relay should be checked. Often the
plastic cover that goes over the relay can be removed,
and the switch contacts gently files. Also check for cold
solder joints on the relay solder points.
Also keep in mind
that the 50 volt coil voltage will usually test at 70 volts (because
there is no load, and the voltage is unregulated). The 25 volt
system will often test as high was 38 volts.
Is the Solenoid L/R Select Relay Bad?
Be aware that relays can go bad too. This can especially
happen if transistor Q29 locks on for an extended time, and leaves power to the
relay turned on. The relay can actually get so hot, it burns the
relay contacts together. Sometimes the solder joints on the L/R select
relay can go "cold" or fatique. This often will make an L/R select relay not work
(but reflowing the relay solder joints can generally fix this).
Wrong L/R Relay installed on some TftC Games.
During production of Tales from the Crypt, the wrong L/R select relay on the PPB board
was installed.
This caused solenoids to activate randomly, and flash lamps to not activate at all.
The problem was the PPB's K-1 relay was installed with a 24 volt AC relay, instead
of a 24 volt DC relay. The incorrect AC relay has a relay coil winding of about 2 ohms,
while the correct DC version is about 650 ohms! The lack of ohms will cause the
relay to burn and fail. The relay can be identified easily because it is labeled
"24v AC", while the correct relay is labeled "24v DC" (or the relay's winding
can be measured with a DMM). Games with serial number
101664 or later have been inspected for this problem. If this 24 volt AC relay is
installed, replace it with the correct 24 volt DC relay. This was mentioned in
service bulletin number 52.
Turning on Relay L/R to test both coils/flashers that driver transistors
Q39-Q46 control. Here transistor Q29's metal tab is grounded with an
alligator clip. Note there is a ground test point on the CPU board to
the right of connector CN10.
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Transistor Testing procedures, circuit board out of the game.
If a circuit board is out of the game for some reason,
test all the solenoid/flasher driver transistors. It only
takes a moment, and will ultimately save time.
To test a transistor, set the
digital multi-meter (DMM) to the "diode" position.
Testing a TIP122/102 transistor on the CPU board.
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- TIP122/102: Put the black lead of the DMM on the center lead
or on the metal tab of the transistor. Put the red lead of the DMM on
each of the two outside legs of the transistor one at a time. The DMM should show a reading
of .4 to .6 volts. Any other value, and the transistor is bad and will need
to be replaced.
Testing a TIP36c on the PPB board.
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- TIP36c: Put the red lead of the DMM on the center lead
or on the metal tab of the transistor. Put the black lead of the DMM
on each of the two outside legs of the transistor one at a time. The DMM should show a reading
of .4 to .6 volts. Any other value, and the transistor is bad and will need
to be replaced.
Testing a 2N4401 pre-driver on the CPU board.
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- 2N4401 (pre-drivers): Put the red lead of the
DMM on the center lead of the transistor
(note this transistor doesn't have a metal tab).
Put the black lead of the DMM on each of the two outside
legs of the transistor one at a time. The DMM should show a reading of .4 to .6 volts. Any other
value, and the transistor is bad and will need to be replaced.
Testing a TIP42 lamp matrix column driver transistor on the CPU board.
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- TIP42: Put the black lead of the DMM on the base lead
(as facing the transistor, the left leg) of the transistor. Put the red lead of the
DMM on each of the two transistor legs (center and right), one at a time. The DMM should show
a reading of .4 to .6 volts. Any other value, and the transistor is bad and will need
to be replaced.
Most often transistors short when they fail. This will usually
give a reading of zero or near zero, instead of .4 to .6 volts.
For games with "Easy A-Just", enter the diagnostics
with the green button in the "down" position. Then press
the black button. If the green button is "up", the
audits/adjustment menu will be shown instead.
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Testing Transistors/Coils, circuit boards installed in a (near) WORKING game,
using the Diagnostics Test.
If the game powers on, the diagnostics can be used to test most
devices. On games Frankenstein and before, from the attract mode:
- Press the green button inside the coin door to the "down" position.
- Press the black button once to enter diagnostics.
- Press the black button to move from test to test.
- On games WWF Royal Rumble and later, make sure the coin
door is closed while testing coils.
Solenoid Doesn't Work during Diagnostic Tests.
If a solenoid doesn't work from the diagnostic tests, here's what
to check. Turn the game off before doing this.
- On games WWF Royal Rumble and later, make sure the coin door is closed
(otherwise power will be cut to the coils).
- Check all the fuses. A non-working
solenoid could be as easy to fix as just replacing a fuse.
- Find the solenoid in question under the playfield. Make
sure the wire hasn't fallen off or become cut from the coil lug
(a very common problem).
- Make sure the power wire (the one connecting to the diode's
banded side) has not broken "up stream". Power wires are
"daisy chained". If a power wire breaks on a previous coil
in the chain, no coil "downstream" will have power.
- If the above is correct, make sure the windings of the coil
haven't broken off from the solder lugs. If one has broken, it can be
resoldered. Make sure to sand the painted enamel insulation
from the wire before re-soldering.
- Check the coil diode. For all DataEast/Sega games, the
coil diode will be right on the coil, with the banded side of the
diode connecting to the power side of the coil.
A Coil Doesn't Work, What To Do.
The following procedures will start at the coil, and work back
to the CPU board, testing components in order. This will eliminate heathly components
and make finding the problem easier.
Testing for Power at the Coil.
Most pinball games (including DataEast/Sega) have power at
each and every coil at all times. To activate
a coil, GROUND is turned on momentarily by the driving transistor
to complete the power path. Since only ground (and not power) is turned on and
off, the driving transistors have less stress on them. With this in
mind, if a coil is artificially attached to ground, it will fire
(assuming the game is turned on and in attract mode). This procedure
tests for power at the coils (does not work for flipper coils):
- First check the fuse! A non-working
coil could be as easy to fix as just replacing a fuse.
- Turn the game on and leave it in "attract" mode.
- Lift the playfield.
- On games WWF Royal Rumble and later, close the coin door.
- Put the DMM on DC voltage (100 volts or greater).
- Attach the black lead of the DMM to the grounding strap by the playfield prop rod.
- Touch the red lead of the DMM on either lug of the coil in question.
- The DMM should show a reading of 25 to 80 volts DC. Switch the red test
lead to the other lug of the coil, and the same voltage should be shown again.
If the correct voltage reading is not shown, no power is getting to the coil.
If there is power at only one of the lugs, then you have a broken
winding on the coil itself. Replace the coil or fix it (if the winding
is an outside winding, you can remove the paper label and unwrap a turn
of wire, sand the insulation off, and resolder the coil winding to the lug).
- If no power is getting to the coil at either lug, it may be a coil that is
L/R relay selected. Push the green coin door button down,
and press the black button. This will
put the game in diagnostics mode. This should
de-energize the L/R relay, and turn the power to the coil
in question on (except for games Time Machine to the Simpsons).
If there is still no power (or the game is Time Machine to the Simpsons),
use an alligator clip from ground to the metal tab of transistor Q29,
to activate the solenoid L/R relay, and retest for power
at the coil again.
- A broken L/R relay can cause power to not get
to a coil. This will always affect more than one coil. Cold solder
joints on the L/R relay to PPB board solder pads can impede power too.
- If no power is getting to the coil, a wire may be
broken somewhere. Trace the power wire. Remember, the power wires
are "daisy-chained" together. So if there is a break in the wire
at a previous coil, the coils downstream will not get power.
Coil Test to Make sure the Coil is Good.
Here's another method of testing coils, which is more "low-level".
This will test if the coil itself is good, and that there is power
at the coil.
- Game is on and in "attract" mode, and the playfield lifted.
- On games WWF Royal Rumble and later, close the coin door.
- Connect an alligator clip to the grounding strap by the playfield prop rod.
- Momentarily touch the other end of the alligator clip to the GROUND lug of the coil
in question. This will be the coil lug with the single (thinner) wire attached.
The ground coil lug is also the one with the non-banded side of the
diode connected. If accidentally the alligator clip is touched
to the power side of the coil, the game will reset and/or blow a fuse,
as the solenoid high voltage is being shorted directly to ground.
- The coil should fire.
If the coil does not fire, it may be a coil that is
L/R relay selected. Push the green coin door button into the down position,
and press the black button. This will
put the game in diagnostics mode. This should
de-energize the L/R relay, and turn the power to the coil
in question on (if the game is Time Machine to the Simpsons,
ground transistor Q29's metal tab to
energize the L/R relay, because the coil/flashlamp banks are reversed).
- If the coil still does not fire, either the coil itself is bad,
or the coil's fuse is blown causing power to the coil to be absent.
Testing TIP122/102 Transistor and Down-Stream Wiring/Coil.
If the coil fires in the above test, there may be a transistor problem.
Next test the TIP122/102 transistors. Only
do this for the TIP122 or TIP102 transistors! Damage can occur if this
test is done on other transistors (like TIP42 or TIP36). This test
will test everything from the CPU board down to the coil itself. If
the TIP122/102 and coil pass this test, and the coil still doesn't
work in game play, the problem is more "up stream". All that is
left is the 2N4401 pre-driver transistor, and the logic TTL chip
that ultimately controls the whole process (a 7402 for the special
coils or 7408 for the constant power solenoids), and the PIA 6821 chip.
Note the TIP36c transistors can be indirectly tested using this method too, BUT
the TIP122 pre-driver must be grounded. All TIP36c transistors use a TIP122/TIP102
as a pre-driver. If the metal tab on the pre-drive TIP122/TIP102 is grounded,
this will activate the TIP36c, which will energize it's associated coil.
- Game is on, and in diagnostic mode (push the green coin door button down,
and press the black button on games Frankenstein and before to go into diagnostics mode).
- Remove the backglass.
- On games WWF Royal Rumble and later, close the coin door.
- Find the transistor that controls the coil and/or flasher in question
(refer to the manual).
- Attach an alligator clip to the grounding strap in the bottom
of the backbox.
- Momentarily touch the other lead of the alligator clip to the metal
tab on the TIP122/102 transistor (only works on these, may damage other
transistors).
- The coil or flasher should activate.
- If the coil or flasher does not fire, it may be a transistor that is multiplexed
through the L/R relay.
- To energize the L/R relay (which will fire the other coil/flasher
that is multiplexed), attach another alligator clip to the grounding strap in the
backbox. Connect the other end of the alligator clip to the metal tab of transistor Q29.
This will energize the L/R relay on the PPB or MRB board.
- If the coil or flasher does not fire, and the coil or flasher
did fire in the previous test, there probably is a wiring problem.
A broken wire or bad connection at the connector plug would be most common.
It is also possible a driver or pre-driver transistor is bad. Use the DMM meter
to test the transistors on the board (see
Transistors Testing Procedures for details).
"Special Soilenoids" Problems (Trickiness on CPU Revision 3 Games).
Before CPU board Revision 3, the six special coils were not CPU controlled.
Instead simple circuitry was used to sense and turn on the special coils. With the introduction
of CPU Revision 3 (Back to the Future and later), the special coils became CPU
controlled ("non-reflexive" circuitry). However to keep the CPU boards backwards compatible,
the old special coil circuit was left intact on the Revision 3 CPU boards (even
though Revision 3 games did not use it).
On games Back to the Future and later, there is a potential problem with this backwards compatibility.
The old special coil circuitry can be damaged, and cause the special coils to lock on. This can
be very frustrating. For example, say a pop bumper coil locks on immediately when the game
is powered on. After replacing its associated TIP122 transistor and the 2N4401 pre-driver transistor,
and checking the coil's diode, the coil is still locked on! So go back a step further,
and replace the 7402 chip at location 12A or 12B. And still the coil is locked on. Finally go
all the way back, and replace the 6821 PIA chip at location 8H or 9B. Yet still the coil is
locked on!
The problem could be in the parallel, but unused, old special coil circuit! If just one of the
small capacitors at locations C40 to C45 (.1 mfd) shorts, its associated coil
can lock on. This is a very common, but confusing problem. Also, one of the diodes at
locations D1 to D6 (1N5234 or 1N4735, 6.2 volts zener),
or the resistor pack at R24/RA24 (4.7k x 8) can short
(less likely, but still worth checking). In CPU Revision 3 games, these components
are unused, but they can still become damaged!
On games prior to Back to the Future, I have seen a cases where a special coil
would not lock-on until a game was started or the game entered diagnostic mode.
This is a clear that the problem is *not* the driver transistors, but
is related to the Special Solenoid's switch circuit. In the case I repaired it
was one of the D1 to D6 1N5234 zener diodes next to
connector CN18 (the special solenoid switch
input connector). These diodes are easy to test using a DMM set to
diode mode - .4 to .6 volts (or 1.8 volts if the DMM leads
were reversed), except for the shorted diode which tested 0 volts.
It is easy to determine which circuit a game is using. If connector CN18 (upper
right hand corner as facing the CPU board) has a plug connector attached, the game is using the older
special coil circuit. No connector at location CN18 means the game is
a ("non-reflexive") CPU Revision 3 or later machine.
Special Solenoid Logic Flow.
For Special Solenoids (SSa to SSf), here is the logic flow. This
is useful to know if you are having a problem with a special
solenoid.
SSx: 6821 PIA 7407 7402 2N4401 TIP122 to Coil
--------------------------------------------------------
SS1: 8H (pin 19) to 11C to 12A to Q2 to Q6 CN19-3
SS2: 9B (pin 19) to 11C to 12A to Q3 to Q9 CN19-4
SS3: 11D (pin 39) to 11C to 12A to Q4 to Q10 CN19-6
SS4: 8H (pin 39) to 11C to 12A to Q5 to Q11 CN19-7
SS5: 11D (pin 19) to 11C to 12B to Q6 to Q12 CN19-8
SS6: 9B (pin 39) to 11C to 12B to Q7 to Q13 CN19-9
Since pre-Back_to_the_Future games use hardware logic to fire the solenoids,
there are some other smaller (and easily damaged!) components
that can fail too. Check capacitors C40 to C45 (.1 mfd),
diodes D1 to D6 (1N5234), and resistor
network RA24 (4.7k x 8). If these become damaged, a special solenoid
can "stick on". Even if the game is Rev3 or later (CPU controlled
special solenoids), damage these components can cause problems.
Testing the Special Coil Circuit.
The old special coil circuit can be easily tested. This procedure
works for all CPU boards from Revision 1 to Revision 3.
- Remove the backglass.
- Turn the game on, and start a game. Leave the ball in the shooter lane.
- If there is a connector on the CPU board at CN18, remove it.
- Connect an alligator clip jumper wire to the ground strap in the bottom
of the backbox.
- Touch the other end of the jumper wire to each pin, 1 to 6, of CPU board
connector CN18. Each respective coil should fire (depending on the game,
there may be some special solenoids not used, and hence touching a pin or two may
do nothing).
Testing the under-the-playfield Relay Boards.
On most DataEast/Sega games, there are a mix of some 50 volt
and 25 volt coils. For games without a PPB board (Laser War, Secret Service),
there is a SMIG relay board to power the 50 volt coils. A TIP122/102
transistor on the CPU board energizes the under the playfield
relay on this board. This relay then turns on the ground to the 50 volt
coil, motor or other device. This was done because the original TIP122 on the CPU
board couldn't handle the current draw of motors or 50 volt coils.
The under the playfield SMIG relay boards were no longer required for 50 volt coils
on games with a PPB board. That's
because the PPB board had TIP36c transistors to control the
50 volt coils, replacing the small SMIG relay boards.
Many newer DataEast/Sega games still use under-the-playfield relay boards.
Sometimes they are used to turn off and on sections of the playfield
GI lamps. They are also used to power motors.
It is easy to test the under the playfield relay boards.
Connect an alligator clip wire to the "DRV" lead on the small
relay board (on games WWF Royal Rumble and later, close the coin door).
Connect the other end of the alligator clip
to ground (grounding strap by the playfield prop rod).
This will energize the relay (a "click" should be heard),
and the device it powers should also operate.
If this is a GI relay, the connecting GI playfield lighting
string should turn off.
Grounding the "DRV" lead (blue wire, second from
bottom) with an alligator clip will energize the
device this board controls. In this case (Jurassic Park),
this relay turns on and off a string of playfield GI lamps.
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Cold, Fatiqued or Cracked Solder Joints on the Relay Boards.
Quite often the solder joints on the under the playfield relay boards
are cracked or "cold". If there is a problem with any device
that is controlled by a relay board, re-solder all the solder points
on the relay board. This is a very common problem!
I've Done the Above Tests & they Work, but the Coil still doesn't
work in Game mode.
After performing all the above tests and replacing/testing the coil, TIP36c (if used),
TIP122/102 and/or the 2N4401 transistors, the coil still doesn't work in game mode!
Now there are the logic components that need to be tested or replaced.
Here is breakdown of what logic chips control the following TIP122/2N4401 transistor
pairs:
- Q38/Q46, Q37/Q45, Q36/Q44, Q35/Q43:
The 7408 at 4J, which connects to 5H (74LS273), which connects to PIA 11D (6821).
- Q34/Q42, Q33/Q41, Q32/Q48, Q31/Q39:
The 7408 at 3J, which connects to 5H (74LS273), which connects to PIA 11D (6821).
- Q22/Q30, Q21/Q29, Q20/Q28, Q19/Q27:
The 7408 at 2J, which connects to PIA 5F (6821).
- Q18/Q26, Q17/Q25, Q16/Q24, Q15/Q23:
The 7408 at 1J, which connects to PIA 5F (6821).
- Q2/Q8, Q3/Q9, Q4/Q10, Q5/Q11:
special coil (switched solenoid) drivers. Connects to chip 12A (7402).
On CPU revision 1 or 2, the logic ends there.
On CPU revision 3, chip 12A (7402) connects to
chip 11C (7407), and then to PIA 8H or 9B or 11D (6821).
On all revisions, resistor network RA24 (4.7k x 8), capacitors C40-C45 (.1 mfd),
and diodes D1-D6 (1N5234) are used and can fail (causing the affected
coil to lock on).
- Q6/Q12, Q7/Q13:
special coil (switched solenoid) drivers. Connects to chip 12B (7402).
On CPU revision 1 or 2, the logic ends there.
But on CPU revision 3, chip 12B (7402) connects to
chip 11C (7407), and then to PIA 11D or 9B (6821).
On all revisions, resistor network RA24 (4.7k x 8), capacitors C40-C45 (.1 mfd),
and diodes D1-D6 (1N5234) are used, and can fail (causing the affected
coil to lock on).
Turning on Relay L/R to test both coils/flashers that driver transistors
Q39-Q46 control. Transistor Q29's metal tab is grounded with an alligator clip.
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Installing a New Transistor.
After determining a coil transistor is bad,
there are a few things to keep in mind. Most TIP122/102 transistors
also have a "pre-driver" transistor (2N4401 or NTE123AP).
When replacing a coil's TIP122/102 transistor, it's a good idea to also replace
its corresponding pre-driver. It will be located near the TIP transistor.
See the schematics to determine the specific pre-driver transistor(s).
Games with a PPB board
use a bigger TIP36c driver transistor for high voltage devices. These
TIP36c transistors have TWO pre-drivers: a TIP122/102 and a 2N4401
transistor. Again, if the TIP36c has failed, it's a good
idea to replace both corresponding pre-driver transistors.
Replacing the pre-driver transistors is optional (if they test
OK). These pre-drivers can be tested instead of just
replacing them. However if the driver transistor has failed, the
pre-driver was probably over-stressed too.
It is just a smart idea to replace the pre-driver transistor(s) too.
Replace TIP122 transistors with TIP102?
This is a very common question. The TIP102 is a more "hardy" transistor
than the TIP122, yet works exactly the same. So why not replace a bad
TIP122 with a TIP102? Some people
would argue against this, claiming the TIP102 will not go bad as quickly,
and therefore can cause more heat and damage the circuit board before or
while it fails. But if either type transistor is already shorted, it really doesn't
matter if it's a TIP122 or TIP102. It's still shorted, and it will still cause
the same heat damage. My recommendation is to
replace all bad TIP122 transistors with the more robust TIP102.
The diode mounted right on the coil,
Note the two thicker red power wires go
to the banded (power) side of the diode.
The single thinner wire goes to ground.
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When Replacing Bad Driver Transistors... (a repeat warning!)
ALWAYS check the coil mounted diode too! And ALWAYS check the coil resistance
(anything below 3 ohms is a problem.) Often the coil mounted diode will break, causing the
driving transitor to fail. If the diode is not replaced also, the driving transistor
will fail again and again. This is often overlooked in DataEast/Sega games.
Coil Diodes.
On all DataEast/Sega pinball games, each and every
coil must have a coil diode.
This diode is VERY important. When a coil is energized, it
produces a magnetic field. As the coil's magnetic field
collapses (when the power shuts off to the coil),
a surge of power as much as twice the energizing voltage
spikes backwards through the coil. The coil diode prevents
this surge from going back to the circuit board and damaging components,
or causing the CPU to get confused (which often results in a game
reboot or strange scoring behavior).
If the coil diode is bad or missing, it can cause several problems.
If the diode is shorted on, coil fuse(s) will blow. If the diode
is open or missing, strange game play will result (because
the CPU board is trying to absorb the return voltage
from the coil's magnetic field collapsing). At worst a missing
or open diode can cause the driver transistor or other
components to fail.
When Replacing a Coil Diode...
Remember to always install a coil diode with the banded end
of the diode to the power wire coil lug! The power lug is the one
with the thicker red or purple wire(s) connected to it.
This is usually the lug with TWO wires connected to it (because
the power wires "daisy chain" from coil to coil). If a diode is installed
in reverse, it will instantly short and be ruined when power is applied
(and often blow a fuse, and sometimes kill the coil's driving transistor!).
Diodes Mounted on the Coil.
Sometimes a diode lead breaks away from the coil
by vibration. When replacing a coil, the repair person
can install the coil wires incorrectly (the power wire should always be
attached to the coil's lug with the banded side of the diode).
The coil diode as used on a flipper coil, Robocop
and later. This lower flipper coil is on Jurassic
Park, and hence has an EOS switch.
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Test a Diode on a Coil?
Coil diodes can be tested. They do fail and they do break. This is true mostly for just
the coil diodes that are actually mounted on the coil itself. Testing
coil diodes is somewhat a waste of time. If a coil diode is suspected
bad, just cut the old one off and solder a new one on. Diodes are so inexpensive,
it's not really worth trying to test them. Most bad coil diodes are physically
broken, and the damage can usually be seen.
If the coil diode is mounted on the coil (which it should be!),
clip one end of the diode off the coil lug to
test it (that's why just replacing the diode is a good idea if
a problem is suspected).
Use the DMM set to "diode" setting.
With the black lead on the banded side of the
diode and the red lead on the non-banded side, the DMM
should show between .4 and .6 volts. Reverse the
leads (red lead to banded side of diode and black lead to non-banded side),
and it should show a null reading. If these readings are not shown, replace the diode with
a new 1N4004 diode. Don't forget to resolder the cut diode lead
if the diode is not replaced.
Test the Coil Resistance with a DMM.
After replacing the driver transistor, ALWAYS measure the resistance
of the associated coil. This is important.
If a coil gets hot (becuase its driver transistor was shorted),
it can burn the painted
enamel insulation off the coil windings. This lowers the overall resistance
of the coil because adjacent windings short together.
If resistance gets much below 3 ohms, the coil becomes
a "short", and will fry its associated driver transistors very quickly!
Installing a New Coil.
Many replacement coils will come with a diode soldered across
its solder lugs. All coils should have a diode mounted on them.
Remember to install the coil wires correctly!
The coil's ground wire (usually the smaller wire) MUST go to the
lug of the coil with the non-banded side of the diode. The power wire
connects to the lug with the banded side of the diode. If
the wires are reversed, this essentially causes a shorted diode,
which destroys the diode and sometimes the driving transistor.
Check nearby coils for reference. Remember
the power wires are usually "daisy chained" together. So the power
lug of the coil is the one with two wires connected to it.
Coil Doesn't Work Check List.
If a coil doesn't work in a game, below is a check list to
help determine the problem.
Before starting, is the coil stuck on? (Hint: is there heat, smoke and a bad
smell?). If so, the coil's driving transistor has probably failed.
Turn the game off and check the driving
transistor, and replace if needed. See Transistors
Testing Procedures for more info.
If the coil just doesn't work, here's a list of things to check:
- On games WWF Royal Rumble and later, make sure the coin door is closed!
- Have the power wires fallen off the coil's solder lugs?
- Is the coil damaged? Has the internal winding broken off the
coil's solder lug?
- Is there power at the coil? See Testing for
Power at the Coil for more details.
- If there is no power at the coil, check its fuse.
- Check the other coils that share one of the same wire colors.
Are they working too? If not, suspect the fuse that handles these coils.
- Power to coils are often ganged together. If the power wire
for this coil has fallen off a previous coil in the link, power may not get
to this coil.
- Using the DMM and the continuity test, make sure the coil
connects to the correct connector/pins on the CPU board.
- Check the driving transistor. Usually this transistor will short on
when it fails, but not always.
Flippers don't work, and Neither do the Special Coils.
The flippers do not work during game play, and all
or some of the special coils (pop bumpers, slingshots) do not
work either. If the fuses are Ok, check the chips at locations
12B and 12A (7402). Often the chip at 12B will fail, causing
the flippers and the special coils to not work. The chip at
12B is also used to enable "blanking". If this chip has failed,
often the CPU will not even boot properly.
Problems with Transistor Q54 on Monday Night Football.
DataEast issued service bulletin number 22 regarding the problem of
transistor Q54 failing. This is caused by the outhole kicker coil
(under the metal lower ball arch) getting a short between
one of the coil lugs and the coil stop. This shorts 32 volts to the
switch matrix, which eventually causes transistor Q54 to fail.
To fix this, remove the lower ball arch. Inspect the outhole kicker's
coil stop. Put a piece of electrical tape between the coil's lugs
and the coil stop to prevent this electrical short.
Problems with LAH, GnR Magnets.
The under-playfield mounted magnets on Last Action Hero and Guns N Roses
are very problematic. First note there are three 3amp slow-blow fuses, one for
each magnet. These fuses are mounted under the playfield by the magnets.
There is also a small magnet drive board under the playfield.
If a fuse is blown, it would be very common for one (or all three) of the
20P10L mosFETs on the magnet board to be bad. Just replacing the fuse
will often lock-on the associated magnet at game power-on.
If this is the case, my suggestion is to completely rebuild the magnet board.
This involves replacing the original 74HC273 chip (20 pins) and the three
MosFETs. I have found that if one magnet does not work, it's just a matter
of time before they all don't work. Rebuild the board and be done with.
And often the driving TTL chip will be blown too.
Replace the 74HC273 with a 20 pin socket and install a new chip. Any TTL
of similar 273 type will work (that is 74HC273, 74LS273 or 74HCT273, I have tested
these all). Also replace the three MosFETs with IRL540 MosFETs. Don't mess
around, use the more robust IRL540 if you want this board to stay working.
And obviously keep the heat sinks mounted on the MosFETs.
Lastly, reflow the .156" male header pins on the magnet board. Usually
the pin that is the "return" voltage going to the three MosFETs has
cracked solder joint around the connector pin.
3c. When things don't work: Game Resets (Diodes, Filter Caps,
Bridge Rectifiers, Power Supply) and Strange Game Behavior.
A very common problem with DataEast/Sega games is random game lock-ups. This can happen
any time, but seems most prevelant during hard game play (like multiball). The game
just locks, no scoring, displays are frozen, lamps locked in their last state.
Another very confusing problem can be just strange game behavior. Solenoids can
fire that were not switched, or strange game features and scoring occur.
Broken Coil Diodes.
The most common cause of these problems is a broken diode on the coil(s).
If a diode breaks (or fails) on a coil, this allows a demagnetizing spike to
go back to the CPU board. As a DC coil's electromagnetic field collapses when it is de-energized, it creates
a spike that travels backwards. The purpose of the diode(s) on a coil is to
stop this spike from going back to the CPU. The constant jarring of a
coil can cause the diode to break or crack.
The most common coil diodes to break are located on the flipper coils.
The pop bumper and slingshot coils also can break their diodes.
On coils other than the flipper coils,
a broken coil diode often causes the coil's driving transistor to short.
If this happens, the coil will stay "locked on" as soon as the game is
turned on. If the transistor is replaced on the CPU board, and the coil diode
is not also replaced, the transistor will short again. This is a very
commonly overlooked problem!
Random game lock up can happen if a flipper coil's diode breaks or fails.
This is noticed the most during multiball play, because the flippers are used
the most during multiball. The best solution is just to replace every flipper coil
diode. These 1N4004 diodes are very cheap and easy to replace. It only
takes a few minutes to cut the old ones off and replace them with new
1N4004 (or 1N4007) diodes. Testing these diodes really is a waste of
time, as they are so cheap (and can often test as good when they are
really bad).
The Diode's Band: Install them Right.
Remember when replacing coil diodes the new diode MUST be installed
with the band in the same direction as the removed diode (assuming
it was installed correctly, which isn't always a good thing to assume).
The diode's band is always connected to the power lug of
a coil. If a diode is installed in reverse, that is the equivalent
to having no diode installed! Note diode installation is slightly more complicated
to figure out on three lug flipper coils. On two lug coils, the power lug is usually the thicker
of the two wires. Check the schematics if unsure.
The backbox bridges, filter capacitors, and fuses, as used on a large 192x64 dot
matrix games. The two filter caps are used for BR1 (CPU controlled lamps) and BR3
(score display, only present on games with the large 192x64 DMD). BR2 is used for
+32 volt solenoids, and hence does not need a filter capacitor. The game pictured
here is Baywatch. All other DataEast/Sega games without the 192x64 score display
will be lacking BR3, the second large capacitor, and fuse F3.
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DB1 Power Supply Bridge Rectifier Problems.
The power supply board's DB1 bridge rectifier supplies +5 volt and +12 volts
to the entire game. This bridge can fatiqued and cause the game
to have random resets. Often the power supply's solder points for
this bridge are cracked (or even have black
rings around the bridge leads, caused by voltage arcing across the
crack). The bridge should be replaced with
a new one (35 amps, 200 volts or higher).
The backbox bridges, filter
capacitor, and fuses, as used
on all games up to Guns N
Roses. The one filter cap is
used for the CPU controlled
lamps. The game pictured
here is Tommy. |
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Replacement Bridges and Diodes.
All the stock bridges installed in DataEast/Sega games are 35 amps 200 volts
with lug (not wire) terminals.
The original part number will be something like "MB3502" or "MB352"
(signifying 35 amps at 200 volts). A replacement bridge
can be any voltage or amp value at that rating, or higher. Since the cost is usually
no different, buy 35 amps 400 volt replacement bridges with lug terminals.
These are available from Competivitive Products Corp (800-562-7283).
Radio Shack even sells 35 amp bridges at 50 volts (which isn't
enough voltage). But if you look at the bridge inside the Radio Shack package,
often then are labeled 3502 or 352 (35 amps 200 volts), and not 50 volts.
Always buy only the labeled bridges from Radio Shack. Sometimes
these "35 amp" bridges are labeled 1001W (10 amp 100 volts!).
Obviously put that one back and grab another!
+5 volt Filter Capacitor(s).
The +5 volt logic filter capacitor on the power supply board is
very important. This keeps the +5 volts smooth and steady. If
this capacitor fails, the +5 volts can become rough, and cause
the CPU to reset during game play. This can often be seen
during game play, when both flipper buttons are pressed, or during
multiball when a lot of coils are firing simultaneously.
Power supplies #520-5047-00, #520-5047-01, #520-5047-02 (Laser War to
Guns N Roses) used a single 18,000 mfd 25 volt capacitor at C4 to
filter the +5 volts logic. When DataEast/Sega switched to the
super-sized 192x64 dot matrix display, the power supply changed
to #520-5047-03. This newer version switched from a single 18,000 mfd
filter capacitor, to four 4700 mfd 25 volt caps at C11 to C14 (for
a total of 18,800 mfd). This was done for reliability reasons. If
one of the capacitors failed, the other three could probably still filter
the +5 volts enough to keep the game running.
DataEast power supply #520-5047-00 (small
DMD game). DB1 is the square gray metal
"block", right middle of this picture.
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For additional reliability on games Laser War to Guns N Roses,
it is a good idea to solder an
18 gauge wire from the "+" lead of bridge DB1 to the "+" lead
of capacitor C4. Solder another 18 gauge wire from the "-" lead of the
bridge DB1 (the lead diagonal to the bridge's "+" lead) to the "-" lead of capacitor
C1. These added wires will help prevent future problems with cracked solder joints on
the power supply board components.
The same treatment can also be done on the four games that use
power supply #520-5047-03 (Maverick, Frankenstein, Baywatch, Batman Forever).
But instead solder the 18 gauge wire from the "+" lead of bridge DB1 to the four
"+" leads of capacitors C11 to C14 (daisy chain the wire).
Solder another 18 gauge wire from the "-" lead of the
bridge DB1 (the lead diagonal to the bridge's "+" lead) to the "-" lead of capacitors
C1. This is a less important modification on this power supply, but is
still a good idea.
Power Supply Connectors CN1 and CN2.
On the power supply there are two "square" connectors (opposed to the
inline connectors). Connector CN1 provides incoming power to the power
supply board. Connector CN2 is a centralized ground plug. If either
of these connectors have cracked or cold solder joints on the power supply
board, random game resets can occur. Check these connectors for cracked or
burnt pins on both the power supply board, and the connector plug.
The large square connector
is CN1. Notice the burn mark
on the plastic housing on the
top right side (pin 10,11,12),
which supply 9 vAC to the
power supply to create +5
volts logic and +12/-12 volts
(for the sound board).
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Here are the pinouts for the main power connector CN1 (power supply generation differences
are listed). Pins 1,2,3
are the pins surrounded by the "notches" on the sides of the connector plug.
- CN1 pin 1: 18 volts from bridge BR1. This goes directly to power supply connector
CN4 pins 5,6,7,8 for the lamp matrix. On games Checkpoint to Guns N Roses,
this also supplies voltage to the power supply's voltage regulator VR1
which creates +12 volts for the DMD, going to CN5 pin 5 (for games with 128x16 and
128x32 dot matrix displays only).
- CN1 pin 2: 32 volts from bridge BR2 for the solenoids.
- CN1 pin 3: 32 volts from bridge BR2 for the solenoids.
- CN1 pin 4: High voltage for the displays (games with alpha-numeric and 128x32 displays only).
- CN1 pin 5: Not used.
- CN1 pin 6: Goes directly to power supply connector CN3 pins 1,2.
- CN1 pin 7: High voltage for dot matrix display (unused on pre-dot matrix display games).
- CN1 pin 8: Not used.
- CN1 pin 9: High voltage for dot matrix display (ground on pre-dot matrix display games.
- CN1 pin 10: 9 volts AC to power supply bridge DB1 for generating +5 volts logic.
It is also used to generate the +12/-12 volts for the sound board, by doubling up
with pin 11's 9 volts (to get 18 volts).
- CN1 pin 11: 9 volts AC to power supply bridge DB1 for generating +5 volts logic.
It is also used to generate the +12/-12 volts for the sound board, by doubling up
with pin 10's 9 volts (to get 18 volts).
- CN1 pin 12: Ground for pins 10,11.
Warning about Power Supply connector CN4.
On all DataEast/Sega power supply revisions, connector CN4 directs
18 volts (CPU controlled lamps) and 32 volts (solenoids) to the game. This connector is
twelve pins, and has NO key pin. If connector CN4
is removed, it is very easy to replace the connector
housing shifted one pin to the right or left! This will immediately blow
either the 18 volt lamp fuse or 32 volt solenoid fuse, which are
both bolted to the rear of the backbox.
Random Game Resets On JP, LAH and TftC.
During game play, the games Jurassic Park, Last Action Hero and Tales
from the Crypt randomly reset.
This occurs beacuse the +5 volt line is shorting against the ground backbox metal
plate. This grounding plate lies behind all of the printed circuit boards mounted
inside the backbox. The metal plate can bow, causing it to intermittently short
against one of the backbox circuit boards. This will cause the game to reset.
To fix this problem, remove all the circuit boards (label the connectors!),
and remount the metal backbox grounding plate to remove the bow. Another
solution is to remove the sound board and affix an insulting material to
the metal plate directly behind the sound board at connector CN2. This will
insulate the metal grounding plate from the sound board (which is the board
most affected by this bowing metal plate). Make sure the insulating material
is non-conductive, and thick enough so it cannot be perforated.
This problem was discussed in service bulletin number 55.
Jurassic Park's Coils Fire at Random.
One of the main playfield wire harness trunks in JP can rub against the
upper right flipper coil stop. The vibration of the flipper coil can
cause the harness to "saw" against the coil stop, shorting the wire(s).
This can cause random coil firing, blown fuses, and switch matrix
shorts. To fix this, first inspect the wires for any cuts or shorts.
Then resecure the wiring harness with nylon wire ties. Use
the ties to pull the wiring harness away from the coil stop.
This problem was discussed in service bulletin number 53.
View this bulletin by clicking
here and
here.
Hook Erratic Slam Tilt Problems.
Intermittently Hook performs strangely, and occassionally "slam tilts"
or kicks solenoids for no apparent reason. This can be caused by an
intermittently grounded switch strobe line. Most often, this is caused
by the green wire with the yellow trace on the left drop target bank.
This wire gets pinched against the playfield support bracket. To fix this,
check this wire on the drop target, and make sure it is not pinched
by the support bracket. Dress the wire with electrical tape or
heat shrink tubbing, and a tie wrap, to prevent future occurances.
This problem was discussed in service bulletin number 37.
Power Supply Missing +5 volts.
If +5 volts is missing on the power supply, the obvious culprits are IC1 (a MC1723 chip) and
transistor TR5 (2N6057). These essentially regulate the +5 volts. But before replacing these,
check the surrounding capacitors. This includes C2 (100mfd 25v), C3 (47mfd 25v),
C5 (470p 50v), C6 (.1mfd 50v), and C7 (330mfd 25v).
3d. When things don't work: Power-On CPU LEDs and Sounds
CPU Power-On LEDs.
At power-on, the CPU board performs several self tests. While watching the LEDs (Light Emitting Diode)
on the CPU board, some information can be derived from them.
If all the self tests pass, the LEDs illuminate in the following order at power-on.
- PIA (Peripheral Interface Adaptor) and +5 volt LED turns on immediately.
- After about 1/2 second, the PIA LED turns off.
- Blanking LED turns on next.
- +5 volt and Blanking LEDs will stay on (until the game is turned off).
The three LEDs on the CPU board.
|
|
The LEDs when the game is booted and running; the blanking
and +5 LEDs are on.
|
|
If there is a problem with the CPU when the game is turned on,
the PIA LED will usually stay on, and not turn off
(and the Blanking LED will not turn on).
Here is what this means:
- PIA LED turns ON (and stays on), blanking LED never turns on:
EPROM at location 5C and/or 5B is bad.
- PIA LED turns ON, turns OFF (and stays off), blanking LED never turns on:
EPROM at location 5C and/or 5B is bad (this LED sequence is very rare).
- PIA LED turns ON, turns OFF, then turns ON (and stays on), and blanking
LED never turns on: 6264 (28 pins) or 6116 (24 pins) RAM at location 5D is bad.
To get any more information from the LEDs, use the CPU Test EPROM
(which is discussed in the section,
CPU Diagnostic Test EPROM).
Power-On Score Display Messages.
When turning on a DataEast/Sega game (Checkpoint or later)
with a dot matrix display, almost immediately the
Display EPROM version should be shown in the
score display. This happens because the dot matrix controller
board has its own Z80A (Checkpoint to Hook with a 128x16 display) or
68B09 (Lethal Weapon to Guns N Roses with a 128x32 display)
or 68000 (Maverick to Batman Forever with a 192x64 display) CPU chip.
The dot matrix controller board will complete its boot-up first,
and hence the EPROM display version message is shown first,
before the CPU board can show its CPU EPROM version number.
The dot matrix controller CPU is used only to display the dot matrix
animations on the score display.
This is in addition to the 6808 (or 6802) CPU chip on the CPU board itself (which is
used to control the lamps, solenoids, switches, game rules, etc.).
After a couple seconds (or after the display EPROM version message,
Checkpoint and later), the CPU
EPROM version (and often country) will be displayed.
The only exception is games with no display EPROM (Simpsons and before without a dot
matrix control board). On these games just the CPU EPROM version will be displayed
(since there is no display controller board and no separate display CPU).
The Display EPROM version shows, but then the Game Stops booting.
This happens on games Checkpoint and later with a dot matrix display. The dot
matrix controller board, with its own separate CPU, boots-up fine. Then the
game's main CPU board does not boot, so the game freezes.
Check the power-on LED flashes to see if they
give any information as to the cause (also see the section below
titled Fixing a Dead CPU).
Power-On Sounds.
As soon as the power is turned on,
the game should play a short word or music phrase.
The phrase will be short, just one or two seconds long,
and it may not be a complete phrase. This is part of
the normal power-on sequence.
3e. When things don't work: DataEast's CPU Diagnostic Test EPROM.
DataEast/Sega has a diagnostic test CPU ROM available for all
DataEast/Sega pinball CPU boards from Laser War ("version 1") to
Batman Forever ("version 3b"). This
provides more indepth diagonstics for their system,
because the flash codes available with the game EPROM really do not give
much diagnostic information.
The diagnostic test EPROM will
need to be burned into an EPROM though. The DataEast test 27512 ROM
image for position 5C is available here.
CPU Jumpers.
Early DataEast games (Laser War to Batman) may require the CPU board
to be rejumpered to use a 27512 EPROM at position 5C.
The two jumpers used in all DataEast/Sega games are J4 and J5. These two jumpers
dictate the maximum size of the CPU EPROM at position 5C. Games Secret Service to Batman
were released with a 27256 EPROM as the largest EPROM usable at position 5C, and
jumper J4 installed and jumber J5 removed. Star Trek 25th Anniversary
to Batman Forever were released with a 27512 EPROM as the largest EPROM
usable at position 5C, and jumper J5 installed and jumper J4 removed.
Use jumper J5 installed and J4 removed when utilizing
the diagnostic test 27512 EPROM at position 5C. Jumpers are discussed
in the section titled Getting Started: Different Board Generations,
CPU Jumpers.
The PIA LED on the right will flash up to eight times with the
diagnostic test EPROM installed. The flashes indicate what
CPU board component is being tested.
| |
|
Diagnostic Test EPROM Usage.
With the power off, replace the current CPU ROM chip at position 5C with
this diagnostic 27512 EPROM. If your game is Laser War to Batman,
the CPU board will have to be rejumpered to use a single 27512 EPROM at
position 5C. Note the three LED lights
in the center right of the board. The far right most LED (labeled "PIA")
will flash as the game powers up with the diagnostic
EPROM installed.
Note there is a long pause after flash one only.
Often the diagostic chip will flash the PIA LED eight times
and turn off, briefly flash the Blanking LED, and then
repeat the sequence of eight PIA LED flashes.
The reason for the second set of eight PIA LED flashes are unknown.
After successfully completing all the flash sequences, the
CPU board's RY1 flipper enable relay will click on.
Then all coil/flashlamp devices will pulse on,
one at a time, in succession.
The Six Special Coils.
The six special coils are NOT tested
by diagnostic EPROM! The reason for this is simple; on CPU board
revisions 1 and 2, the six special coils are not CPU controllable.
Therefore to make the dianostic test EPROM work in these early CPU boards,
the six special solenoids are not tested by the diagostic test EPROM.
How to Count LED Flashes.
When the CPU board is initially powered on with the diagnostic test
EPROM, the PIA LED will immediately turn on. This is considered the
first "flash" (many people think the first darkening of the LED is
the first flash, but this would mean there was only a total of seven flashes,
not eight). Just keep this in mind when referring to the flash
codes listed below. The whole eight LED flash sequence is very fast,
so you'll need a good eye to count the flashes.
The completion of a flash means the associated chip has
passed the diagnostic test.
For example, if the LED turns on and stays on (never turns off),
this is considered the first flash (and hence, the EPROM at 5C is faulty).
If the LED turns off four times then stays lit (the fifth flash), chip 11D would be bad.
DataEast Test EPROM instructions, as written by DataEast.
The test ROM for DataEast CPU boards has the following
functions. When the Test ROM is installed into a CPU board
and power applied, the CPU will perform power-up self tests
and then immediately go into burn-in cycles with no
intervention. It is not required that the Test button be
pressed in order to initiate burn-in cycles.
The power up self-test will check major components on the
CPU board and flash the LED as each one appears normal. If
any fail, the LED will stay on. The tests consist of a
checksum test of the ROM and read/write test of the RAM and
the PIA's. The PIA test will NOT check both sides of all PIA's
since certain PIA ports are designed to be inputs and the
loading on those ports will determine the data seen by the
CPU. However, those ports designed to be outputs will be
written to and read from in order that basic go/no-go
functionality can be checked.
Flash Position Item Tested
----- -------- -----------
1 5C/5B EPROM checksum error
2 5D RAM read/write error
3 5F PIA1 solenoid read/write $2100
4 8H PIA5 switch read/write $3002
5 11D PIA2 lamp read/write $2402
6 11B PIA3 display2 read/write $2802
7 9B PIA4 display1 read/write $2C02
8 7B PIA6 sound read/write $3402
The burn-in test will cycle through the solenoids, lamps, display
and sounds like the present burn-in, with the following exceptions.
- The solenoid cycling will go through all the solenoid matrix
positions.
- The lamps will go through all the patterns of rows and columns,
as well as individual lamps; any shorts or opens will be easily
seen on a test set lamp matrix board [DataEast is referring to a
test fixture lamp matrix board that has 64 lamps, one for each row and column].
- If any matrix switches become closed, the lamp patterns will
stop for a time. The lamp(s) corresponding to the matrix
position of any closed switch(es) will be turned on. This
faciliates testing of the switch matrix. A short time after
the switch matrix becomes clear the lamps will go back to
patterns. This also means that if any switch matrix position
appears closed on power-up, the corresponding lamps will be
turned on after the power-on self tests for a visual indication
of where problems are located.
Written by Neil Falconer, DataEast, 1/6/93
3f. When things don't work: CPU and Display EPROM versions.
DataEast/Sega games often have many versions of the (CPU and display) EPROMs
(Erasable Programable Read Only Memory).
It is important to run the latest available versions of both. The CPU EPROMs
are the game's main programming. This includes the rules for the game, and
control of all the electronic devices and coils. The latest version is very important
on some games. For example, on Jurassic Park, the CPU EPROM code version 5.10 was
changed so the T-Rex motor was pulsed, saving the motor and gearbox from undue wear.
The display EPROMs (games Checkpoint and later) hold
all the graphics and text needed for display on the dot matrix score display.
A separate EPROM was used for this because a separate CPU chip (on the dot
matrix controller board) was used to display the dot matrix animations.
The display EPROM chips are always located on the back side of the dot matrix display.
It is also a good idea to run the latest version of this EPROM code
too. If the game powers-on and shows a country of origin other than
the country desired, changing the display's EPROMs will fix this (note that
Stern's web page with all the EPROM code available for download is
usually for U.S.A. games only).
Games prior to Apollo13 had five different display chips versions. Each
had a letter associated with the version number:
- A = English Language
- G = German Language
- F = French Language
- S = Spanish Language
- I = Italian Language
There was also a plethora of CPU chips released,
something like 17 different chips for each
country where DataEast sold a significant number of games. All chips included
all coinage/pricing info/coin door support, the main difference was the
"default" pricing scheme. There were sometimes other differences, such as
English customer requesting a different pop bumper sound or Japanese
games requiring an extra motor (1994 games from Tommy to Maverick
had to have the same number of motors to pass Japanese customs,
go figure), but such differences were very minor
and few and far between.
Since there were 17 CPU chips they could not always use the leading letter of
the country for the country code. They used AGFSI for the five countries listed
above. They also had other codes that mapped directly to the remaining countries, such as B for
Belgium, C for Canada, J for Japan, etc. But some did not map - one
example was N for Switzerland. S was already taken for Spain and DataEast
wanted something they could remember, so N was picked because
Switzerland was "Neutral". Most of the other assigned country codes letters were
arbitrary starting with the beginning of the alphabet.
The Whitestar hardware system (starting with Apollo 13) added dipswitches
to the CPU boad for default country, this made the country-specific CPU
chip a thing of the past and code releases much easier.
New versions of the CPU and display EPROM code are available on Stern's web site at
http://www.sternpinball.com/rom.htm.
Below is a chart of the EPROMs which can be updated (if you have access to an
EPROM programmer). There may be other
EPROMs in the game (such as sound, or additional display EPROMs). If
multiple versions are not available, they are not shown in the chart below.
Authors of the DataEast CPU Software.
Interestingly, the first games produced by DataEast had
software written by another company. Laser War to Phantom of the Opera had software written
by IT (Incredible Technologies). Not until Back to the Future did DataEast have
"in house" software people writing the assembly langauge code for
their games.
Mistakes in EPROM Sizes in the Documentation?
Many of the later Sega manuals show the EPROM sizes used at
positions 5B and 5C. If these are compared to the actual
EPROM file sizes (available for download at
http://www.sternpinball.com/rom.htm,
there are some differences! The chart below shows the actual EPROM file
sizes, as indicated by the EPROM files themselves.
|
CPU & Display EPROM Versions
|
| Game |
CPU or
Display |
Location |
EPROM
Type |
Version |
| Laser War |
CPU |
5C |
27256 |
? |
| Secret Service |
CPU |
5B |
27128 |
A-6 |
| |
CPU |
5C |
27256 |
A-6 |
| Torpedo Alley |
CPU |
5B |
27128 |
A02-1 |
| |
CPU |
5C |
27256 |
A02-1 |
| Time Machine |
CPU |
5B |
27128 |
A02-3 |
| |
CPU |
5C |
27256 |
A02-3 |
| Playboy 35th Anniversary |
CPU |
5B |
27128 |
A02-3 |
| |
CPU |
5C |
27256 |
A02-3 |
| Monday Night Football |
CPU |
5B |
27128 |
A02-7 |
| |
CPU |
5C |
27256 |
A02-7 |
| Robocop |
CPU |
5B |
27128 |
A03-4 |
| |
CPU |
5C |
27256 |
A03-4 |
| Phantom of the Opera |
CPU |
5B |
27128 |
A03-2 |
| |
CPU |
5C |
27256 |
A03-2 |
| Back to the Future |
CPU |
5B |
27128 |
SA-2 |
| |
CPU |
5C |
27256 |
SA-2 |
| the Simpsons |
CPU |
5B |
27128 |
A02-7 |
| |
CPU |
5C |
27256 |
A02-7 |
| Checkpoint |
CPU |
5B |
27128 |
A1-7 |
| |
CPU |
5C |
27256 |
A1-7 |
| |
Display |
U8 |
27512 |
CP-80 |
| Teenage Mutant Ninja Turtles |
CPU |
5B |
27128 |
A1.04 |
| |
CPU |
5C |
27256 |
A1.04 |
| |
Display |
U8 |
27512 |
? |
| Batman |
CPU |
5B |
27128 |
A1.06 |
| |
CPU |
5C |
27256 |
A1.06 |
| |
Display |
U8 |
27010 |
A1.02 |
|
Start of single 27512 EPROM at location 5C.
|
| Star Trek 25th Anniversary |
CPU |
5C |
27512 |
A2.00 |
| |
Display |
U8 |
27010 |
A1.09 |
| Hook |
CPU |
5C |
27512 |
A4.08 |
| |
Display |
U8 |
27010 |
A4.01 |
| Lethal Weapon 3 |
CPU |
5C |
27512 |
A2.07 |
| |
Display |
ROM 0 |
27040 |
A2.06 |
| Star Wars |
CPU |
5C |
27512 |
A1.03 |
| |
Display
520-5055-00 |
ROM 0 |
27020 |
A1.04 |
| |
Display
520-5055-00 |
ROM 1 |
27020 |
A1.04 |
| OR |
Display
520-5055-01 |
ROM 0 |
27040 |
A1.05 |
| Rocky & Bullwinkle |
CPU |
5C |
27512 |
A1.30 |
| |
Display |
ROM 0 |
27040 |
A1.30 |
| Jurassic Park |
CPU |
5C |
27512 |
A5.10 |
| |
Display |
ROM 0 |
27040 |
A5.10 |
| Last Action Hero |
CPU |
5C |
27512 |
A1.12 |
| |
Display |
ROM 0 |
27040 |
A1.06 |
| Tales from the Crypt |
CPU |
5C |
27512 |
A3.00 |
| |
Display |
ROM 0 |
27040 |
A3.00 |
| Tommy |
CPU |
5C |
27512 |
A4.00 |
| |
Display |
ROM 0 |
27040 |
A4.00 |
| WWF Royal Rumble |
CPU |
5C |
27512 |
A1.06 |
| |
Display |
ROM 0 |
27040 |
A1.02 |
| Guns N' Roses |
CPU |
5C |
27512 |
A3.00 |
| |
Display |
ROM 0 |
27040 |
A3.00 |
| Maverick |
CPU |
5C |
27512 |
A4.04 |
| |
Display |
ROM 0 |
27040* |
A4.01 |
| |
Display |
ROM 3 |
27040* |
A4.01 |
| Frankenstein |
CPU |
5C |
27512 |
A1.03 |
| |
Display |
ROM 0 |
27040* |
A1.03 |
| |
Display |
ROM 3 |
27040* |
A1.03 |
| Baywatch |
CPU |
5C |
27512 |
A4.01 |
| |
Display |
ROM 0 |
27040* |
A4.01 |
| |
Display |
ROM 3 |
27040* |
A4.01 |
| Batman Forever |
CPU |
5C |
27512 |
A3.02 |
| |
Display |
ROM 0 |
27040* |
A3.00 |
| |
Display |
ROM 3 |
27040* |
A3.00 |
| Game |
CPU or
Display |
Location |
EPROM
Type |
Version |
* 27040 Display EPROMs for Maverick and later require an access
time of 120 Nsec or faster (do not use 150 Nsec or slower EPROMs).
Converting Games Laser War to Batman to a Single 27512 EPROM at 5C.
Older EPROM software can be converted to run in a later
CPU board jumpered for a single 27512 at position 5C.
For example, Torpedo Alley uses two 27256 EPROMs at positions
5B and 5C. To convert this to run in a single 27512 EPROM at
5C, type the following DOS command:
copy /b CPU_5B.256 + CPU_5C.256 CPU_5C.512
To convert a game like Time Machine, which uses a 27128 at 5B and
a 27256 at 5C, to a single 27512 at 5C, type this DOS command:
copy /b CPU_5B.128 + CPU_5B.128 + CPU_5C.256 CPU_5C.512
Note the last command double the 27128 image at 5B to fill the entire
contents of the new 27512 EPROM.
Note you can download a ZIP file with all these game EPROMs already converted to
27512k EPROM format.
Remember, in order to use different size EPROMs in the CPU board,
certain jumpers need to be set on the board. CPU Board jumpers are discussed
in the section titled Getting Started: Different Board Generations,
CPU Jumpers. But too sumarize:
27256 EPROM at location 5C, and a 27128 or 27256 at location 5B
(typically games Laser War to Batman):
- jumper J4 installed.
- jumber J5 removed
27512 EPROM at location 5C, no EPROM at location 5B
(typically games Star Trek 25th to Batman Forever):
- jumper J4 removed.
- jumper J5 installed.
Rottendog Reissue CPU board's EPROMs.
Rottendog sells a reissue CPU board that is an copy of the original "version3"
DataEast CPU board. This means the board is set from Rottendog jumpered for
a single 27512k game EPROM (instead of a 27256 and a 27128). To ease in the use of this
board, you can download a ZIP file with all the early DataEast games converted
to a single 27512k EPROM.
DMD Games and two 27020 EPROMs verus a single 27040 EPROM.
Some games like Lethal Weapon 3 sometimes used two 27020 EPROMs for the
display board, mounted at ROM0 and ROM1 socket positions, instead
of a single 27040 mounted at ROM0. Also the ROM files that Stern
provides on their website at
www.sternpinball.com/ROM-code.shtml
are in the dual 27020 format.
These can be combined into a single 27040 EPROM file.
The two 27020 (".020") ROM files
that Stern provides will need to be combined into a single
27040 (".040") file using the MS-DOS binary copy command:
copy /b DISP_ROM1.020 + DISP_ROM0.020 DISP_ROM0.040
Now the new DISP_ROM0.040 file can be burned into a single
27040 EPROM, instead of using the two original 27020 files.
3g. When things don't work: Fixing a Dead Game (CPU)
When turning on a DataEast/Sega game (Checkpoint or later)
with a dot matrix display, almost immediately the
Display EPROM version should be shown in the
score display. This happens because the dot matrix controller
board has its own Z80A (Checkpoint to Hook with a 128x16 display) or
68B09 (Lethal Weapon to Guns N Roses with a 128x32 display)
or 68000 (Maverick to Batman Forever with a 192x64 display) dot matrix controller CPU chip.
The dot matrix controller board will complete its boot-up first,
and hence the EPROM display version message is shown first,
before the CPU board can show its CPU EPROM version number.
The dot matrix controller CPU is used only to display the dot matrix
animations on the score display.
This is in addition to the 6808 (or 6802) CPU chip on the CPU board itself (which is
used to control the lamps, solenoids, switches, game rules, etc.).
After a couple seconds (or after the display EPROM version message,
Checkpoint and later), the CPU
EPROM version (and often country) will be displayed.
The only exception is games with no display EPROM (Simpsons and before without a dot
matrix control board). On these games just the CPU EPROM version will be displayed
(since there is no display controller board and no separate display CPU).
Apparent CPU "Failures".
On Checkpoint to Guns N Roses (all games with small 128x16
and mid-sized 128x32 dot matrix displays), there is a unique problem that can
make the game look very broken. Random horizontal lines
and garbage can be shown on the dot matrix display (but actually the game's CPU has booted
correctly and is working OK). On games with the small 128x16 displays, random horizontal
lines can appear first, followed by the entire display lighting and staying lit.
If the backbox 18 volt lamp matrix fuse (8 amp slo-blo, with the blue/white
wire connecting to the fuse holder) fails, this can cause the dot matrix display to "crash",
causing these problems.
Another way to identify this problem is the lack of any playfield CPU controlled lighting.
The game will "play" (that is, the game will start and play balls), but with score display problems and
no CPU controlled lamps.
Simply replacing the 18 volt lamp matrix fuse (in the backbox)
will fix this problem (providing the associated
components such as the bridge and capacitor are OK). If there
is a lamp matrix power short, or the lamp matrix backbox bridge is bad,
the problem will need to be
fixed or the fuse will continue to immediately fail.
This problem occurs because the +12 volts needed for the dot matrix display
is generated by the 18 volt lamp matrix bridge
and the capacitor/fuse bolted inside the
backbox (through connector CN5 on the power supply).
The 12 volts generated by the power supply board (for the sound board
which comes from connector CN6),
does not provide this voltage to the dot matrix display! Hence the power supply
could be working perfectly, and this problem could still exist.
A Babcock 128x32 display where the 18 volt lamp matrix backbox
fuse has failed. Notice the horizontal "garbage" line across the
bottom center of the display. This problem only seems to affect
the Babcock brand dot matrix displays.
|
|
Interestingly, on 128x32 displays, this problem will only occurs on games with "Babcock" brand dot matrix
displays. The 128x32 displays made by Cherry and Dale seem unaffected by a failed 18 volt
backbox lamp matrix fuse. This happens because the Babcock displays require 12 volts
to function, where Cherry and Dale 128x32 displays do not. This problem can
also arise on Cherry brand 128x16 dot matrix displays.
This stange problem was solved with the advent of the 192x64 super-sized dot matrix
display (Maverick to Batman Forever). An additional backbox 18 volt fuse (F3),
bridge and capacitor was added. This backbox voltage supplied power to a switching
power supply, implemented on the 192x64 DMD display driver board.
This way if the lamp matrix (F2) fuse failed, the dot matrix display remained unaffected.
The Game Will Not Boot or Stops Booting.
On games Simpsons and before, the game just will
not boot. The GI lights come on (and if the game has a dot matrix display, EPROM
version is show), but little else happens. There is something wrong with the
game CPU board.
First check for +5 volts on the CPU board. The voltage range should be
4.9 to 5.1 volts. Test for this voltage at the +5 and ground test points,
just to the right of the battery on the top of the CPU board. If there
is good +5 volts, next check the power on LED flashes, to see if they
give any information as to the cause. Turn the game on and immediately
examine the LEDs.
Square Plug Power Supply Connectors.
Sometimes the square plug power supply connectors get damaged
(these connectors were used on Williams power supplies system 3 to system 11b,
and on DataEast/Sega power supply until 1995). The twelve pin 3J1 power supply
plug handles all the input voltages from the transformer to the power supply,
and often gets burned (the six pin rectangle 3J2 power supply plug is a ground
connector, and usually does not get damaged).
If the 3J1 input plug gets burnt, often the game will not even "boot".
(this plug provides the power for the +5 volt logic circuit).
As the game is first turned on,
the display will come on showing the ROM revision numbers,
and speak it's boot-up phrase, but nothing
more happens (the display turns on because this is a separate computer,
with a separate power plug).
If this 12 pin rectangle plug is burnt, the only answer is to replace it
(both the PCB board wafer plug, and the wire mounted plug).
Finding the part numbers for these connectors was a real
bear, as they were designed in 1971! So
here are the part numbers for these wafer style, mixed pin connectors.
- 12 mixed pin PCB wafer connector, Molex part# 09-18-5121.
- 12 mixed pin wire connector, Molex part# 03-09-1122.
- 6 mixed pin PCB wafer connector, Molex part# 09-18-5061.
- 6 mixed pin wire connector, Molex part# 03-09-1062.
- Male .093" terminal pins for wire connector, Molex part# 16-06-0002.
- Female .093" terminal pins for wire connector, Molex part# 16-06-0001 (new Molex
part# 43080-0001).
Click here for a Molex drawing of these parts.
CPU Power-On LEDs.
At power-on, the CPU board performs several self tests. While watching the LEDs (Light Emitting Diode)
on the CPU board, some information can be derived from them.
If all the self tests pass, the LEDs illuminate in the following order at power-on.
- PIA (Peripheral Interface Adaptor) and +5 volt LED turns on immediately.
- After about 1/2 second, the PIA LED turns off.
- Blanking LED turns on next.
- +5 volt and Blanking LEDs will stay on (until the game is turned off).
The three LEDs on the CPU board.
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The LEDs when the game is booted and running; the blanking
and +5 LEDs are on.
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If there is a problem with the CPU when the game is turned on,
the PIA LED will usually stay on, and not turn off
(and the Blanking LED will not turn on).
Here is what this means:
- PIA LED turns ON (and stays on), blanking LED never turns on:
EPROM at location 5C and/or 5B is bad.
- PIA LED turns ON, turns OFF (and stays off), blanking LED never turns on:
EPROM at location 5C and/or 5B is bad (this LED sequence is very rare).
- PIA LED turns ON, turns OFF, then turns ON (and stays on), and blanking
LED never turns on: 6264 (28 pins) or 6116 (24 pins) RAM at location 5D is bad.
To get any more information from the LEDs, use the CPU Test EPROM
(which is discussed in the section,
CPU Diagnostic Test EPROM).
Bench Testing of the CPU board.
Instead of doing repair and testing of the CPU board in
the game, it is much easier to test the CPU board on the workbench.
The only voltage needed to run a DataEast/Sega CPU board is +5 volts
and ground. A switching power supply, or an old computer power supply
works great for this task. Voltage supplied must be between +4.9 and +5.1 volts DC.
Lay the CPU board on an insulated mat on the work bench. Hook up
a +5 volt power supply to connector CN17, in the upper left hand
corner of the CPU board. The pinouts are:
- CN17 pins 1,2,3: Ground
- CN17 pins 4,5,6: +5 volts
- CN17 pin 7: KEY
- CN17 pins 8,9: No connection
Alternatively, you can also connect +5 volts and ground to the test
points on the top of the CPU board, just to the right of the battery holder.
Actually this is MUCH easier than using the above connector!
Right next to the battery is connector CN17 and the ground and
+5 volt test points.
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Turning the power supply on should boot the CPU board, just like
it was installed in the game. Once the CPU has booted (in attract mode), you can
check the lamp and switch matrix connectors for activity with a
logic probe. Also check the address and data lines on the
EPROMs and CPU. Here are the connectors to check:
- Switch Matrix Rows (returns): CN10 (key is pin 4). Should be HIGH.
- Switch Matrix Columns (drive): CN8 (key is pin 6). Should be PULSING.
- Lamp Matrix Rows (returns): CN6 (key is pin 4). Should be PULSING (low).
- Lamp Matrix Columns (drive): CN7 (key is pin 5). Should be PULSING.
Common Solutions to a Dead CPU.
Corroded batteries can ruin the 6808 (or 6802) CPU socket at 3D (40 pin socket),
the 6264 or 2064C (28 pins) or 6116 (24 pins) CMOS RAM socket at 5D, and the EPROM
sockets at 5B and 5C (28 pin sockets). This is very common.
Battery corrosion must be neutralized on the
printed circuit board. After the affected components are removed,
scrub the afflicted area with a mixture of 50% white vinegar and 50% water.
Then rinse the area with clear water, and let it fully air dry. Sand
any greyed areas clean, and replace the sockets and components. Check all
traces for continuity, as breaks can easily occur which are not visible.
If the game will still not boot, the
most common problem is a dead 6808 (or 6802) CPU at 3D. Either
CPU can be used, but the 6808 is largely unavailable (hence the
6802 is used as a replacement). Also
a dead 6264 or 2064C (28 pins) or 6116 (24 pins) CMOS RAM at 5D is very common.
Blanking Circuit Theory of Operation Service Bulletin.
Sega has a nice document explaining the theory of operation for the
blanking circuit in service bulletin number 75. To check this out, click
here and
here and
here.
3h. When things don't work: Fixing a Dead CPU using Leon's Test EPROM
Leon is a gentlemen from Belgium that has developed an excellent DataEast/Sega test
EPROM for diagnosing a bad CPU board. His web page is at
www.flipper-pinball-fan.be.
With Leon's test EPROM, it's possible to diagnose "difficult" CPU board problems.
I have echoed much of his web page info below. Thanks to Leon for this information and the
test EPROM!
There are a few different versions of the Dataeast CPU boards.
For this, only one difference is significant:
which type of EPROM (27256 or 27512) is in location 5C.
Leon only made a 27512 version of his test ROM, but his DataEast test EPROM
can be used in a CPU jumpered for either a 27256 or a 27512 EPROM (EPROM size
is controlled by a single jumper at J4/J5).
Download Leon's test EPROM here (version4, 3/3/2005).
Using an EPROM programmer, burn this code to a blank 27512 EPROM.
The goal of his test EPROM is to test the CPU chip circuitery and its six connected PIA chips. These PIAs (6821)
are used to send all signals to the external circuits, to the dot-matrix, coils, lights, and via the switch matrix
to all switches (for example, PIA 8H handles the switch matrix). When the CPU and PIA's are Ok, it's almost certain
that the CPU board will fully "boot", and the pinball can be further diagnosed with the internal test/diagnostic
functions. If the machine still doesn't start, there is a good chance either the program EPROM or the memory RAM
may have failed.
It is assumed the voltages to the CPU board are good, which can be checked with a DMM. Don't forget to do this!
Only 5 volts is needed for the CPU board to "boot". If the CPU boots correctly, the middle LED (5 volt) will light
and stay lit, then the right LED (PIA) will light and turn off after a half second. The third LED at the left
(blanking), will then light and stay on.
First Step - Check the Voltage.
The pinball does not start, voltages have been checked using a DMM, and are Ok.
Check the voltages on the CPU board at the GND and +5 volt test points next
to the batteries.
Then check the three LEDs in the middle off the CPU board, on the right.
The +5 volt LED should be on, and probably the PIA LED too. Also sometimes the blanking LED will be
on (but not often).
The three LEDs on the CPU board.
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The LEDs when the game is booted and running; the blanking
and +5 LEDs are on.
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Step Two - Remove the CPU board from the game.
Now take the CPU board out of the game. To avoid confusion, label the connectors as they are removed
with a "sharpie" on the side of the connector.
Step Three - Connect the CPU to an External +5 volt power supply.
Once the CPU board is out, lay the CPU board on an insulted mat on the work bench and
connect it to 5 volts. An old
computer power supply works nicely for a power supply (red=+5 volts, black=ground).
On the left top of the CPU board there's a test point labeled GND and
another labeled +5 volts. Hook up the old computer power supply to
these test points. Alternatively,
hook up a +5 volt power supply to connector CN17,
in the upper left hand corner of the CPU board. The pinouts are:
- CN17 pins 1,2,3: Ground
- CN17 pins 4,5,6: +5 volts
- CN17 pin 7: KEY
- CN17 pins 8,9: No connection
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