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by cfh@provide.net, 04/15/09. Copyright 2000-2009, all rights reserved.
Scope.
Internet Availability of this Document.
IMPORTANT: Before you Start! If you aren't up to repairing pinball circuit boards yourself or need pinball parts or just want to buy a restored game, I recommend seeing the suggested parts & repair sources web page. Table of Contents
2. Before Turning the Game On: 3. When Things Don't Work: 4. Finishing Up:
Thanks to...
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1a. Getting Started: An Introduction to DataEast/Sega Pinball
1b. Getting Started: Experience, Schematics
Little experience in fixing pinballs is assumed. Basic electrical knowledge is helpful, but not necessary. It is assumed you can solder and use the basic features of a Digital Multi-Meter (DMM) such as measuring voltage and resistance. Please see http://marvin3m.com/begin for details on the basic electronics skills and tools needed. This document should help if you just bought your first (or second, or third) pinball "as-is", and hope to fix it.
Got Schematics? Schematics are available on the internet too. Adobe Acrobat is needed to view most files. 1c. Getting Started: Necessary Tools
Non-Specialized Tools Required: Specialized Tools Required: These are electronics tools needed for most repairs. Please see http://marvin3m.com/begin for details on the basic electronics tools needed. Cleaning "Tools" Required:
1d. Getting Started: Parts to Have On-Hand
Parts to have: Order the transistors and diodes from many sources as listed on the suggested parts & repair sources web page.
1e. Getting Started: Different Board Generations
There are three different "official" generations of the DataEast pinball CPU systems. All boards use a 6808 (or 6802) CPU chip, and are essentially a copy of Williams' System 11 CPU board (without the on-board sound circuitry). These are known as Version 1, Version 2, and Version 3. There is actually one other slightly different version of Version 3, which I call version "3b".
CPU Jumpers. Essentially there are only two jumpers used in all DataEast/Sega games: J4 and J5. These two jumpers dictate the size of the CPU EPROM used at location 5C. On games Laser War to Batman, jumper J4 should be installed and jumber J5 removed (these games use a 27256 at location 5C, and a 27128 or a 27256 at 5B). On games Star Trek 25th to Batman Forever (which uses a single 27512 EPROM at 5C and no EPROM at 5B), jumper J5 should be installed and jumper J4 removed.
To sumarize... 27512 EPROM at location 5C, no EPROM at location 5B (typically games Star Trek 25th to Batman Forever):
Deger Design Flipper Circuit.
Solid State Flipper Board (SSFB) Generations. DataEast put out a nice service bulletin on the operations of their solid state flipper design. This is bulletin number 49, and is available by clicking here, and here. There were some complaints that the new solid state DataEast flippers didn't have the same feel as a traditional EOS (End Of Stroke) system flipper. This was because DataEast/Sega's design had a fixed timing (40 milliseconds) for the high voltage (unlike Williams games, whose electronic flippers reacted to the EOS switch, and turned off the high voltage accordingly). With Jurassic Park, DataEast implemented an EOS solid state flipper design. Unlike Williams, DataEast's solid state EOS switch was normally closed. The amount of time the high voltage was turned on to the flipper coil was still fixed, and not controlled by the EOS switch. The EOS switch was implemented for a different reason. When the ball hit an energized flipper bat, and knocked the flipper backwards (opening the EOS switch), the flipper would be pulsed again with the high voltage for the same fixed time (this was accomplished by the EOS switch connected in series with the cabinet flipper switch). This ensured the held flipper would stay in the up position for the player. This was done because of features implemented on Jurassic Park and Last Action Hero. The "Raptor Pit" and the "Ripper" would fire a ball back at the flipper at high speed. This EOS switch was kept for all games after Jurassic Park and Last Action Hero.
On the games Jurassic Park, Last Action Hero, and Tales from the Crypt there is a design problem with their flipper boards, #520-5033-03 (3 flippers, used on JP and TftC) and #520-5070-00 (2 flippers, used on LAH). Games with these board use a normally closed EOS switch on the two lower flippers (only). If an EOS switch is broken or mis-adjusted so it is not normally closed, its corresponding lower flipper will not work (but the upper flipper, if the game has one, will work). This problem was corrected with version #520-5076-00 (3 flippers) and #520-5080-00 (2 flippers), as used on games Tommy and later. The newer #520-5076-00 and #520-5080-00 are backwards compatible. Additionally, starting with Tales from the Crypt, the EOS switch became more robust. This newer EOS switch design is easy to identify because of a "bend" near the end of the switch blade. With the start of Tommy production (after JP, LAH and Tales from the Crypt), the flipper board and EOS switch changed again. The new 3 flipper board (#520-5076-00) is backwards compatible to JP and TftC's flipper board (#520-5033-03). The new 2 flipper board (#520-5080-00) is backwards compatible to LAH's flipper board (#520-5070-00). These new revisions removed the broken EOS switch problem. The JP, LAH and TftC flipper boards can be modified to work correctly, like the later flipper boards. DataEast service bulletin number 54 describes this procedure. To view this service bulletin, click here, here, and here. Flipper board evolution: As interesting trivia, the acronym "TY-FFASI" can be seen silk screened on many of these solid state flipper boards. In the early 1990s, Williams was suing DataEast for a range of things, from board design to playfield plagiarism. DataEast responded with this acronym, which means, "take your fu**ing flippers and stick it".
Games Robocop to Rocky & Bullwinkle (or Playboy and Monday Night Football test games) do not use an EOS switch for the solid state flipper board #520-5033-00. The newer flipper board #520-5080-00 (which supports an EOS switch) can be adapted to work on these older games. The original board 520-5033-00 is no longer available too, so this modification is important if the entire flipper board on these older games needs replacing. Here are the modifications steps to use the newer flipper board 520-5080-00 in older non-EOS switch games:
Power supply boards were changed when different score display power requirements were needed (or the number of flippers changed). Because of this, power supply boards are NOT downward or upward compatible! QUESTION FOR JOE: Apparently most power supplies used in Lethal Weapon and later are labeled "520-5047-00 REV X". The "X" in the "REV" seems to be A, B or C. Is "REV C" the same as "520-5047-03"?
DataEast had several interesting innovations regarding displays. They were the first pinball company to use a dot matrix display (DMD), and the only company to ever use the super-size 192x64 DMD.
DataEast/Sega used three different playfield power boards. The PPB (Popcorn Popper Board) is downward compatible, but not to games with the MRB (Marshmellow Roasting Board - these strange board abbreviations are explained in a later section of this document). The PPB and MRB board held all the flashlamp power resistors. Since the 12 volt flashlamps were powered by the 25 volt solenoid voltage, large 10 watt (usually 4 to 7 ohm) resistors were needed to decrease the current to the 12 volts bulbs (otherwise the 25 volts would immediately kill the 12 volt flashlamps). The PPB and MRB boards housed all these large resistors. The PPB boards also held the TIP36 transistors used for the high voltage 50 volt coils (these TIP36 transistors are pre-driven by CPU board mounted TIP122 transistors). Note TIP36 transistors were not used in games with MRB boards. These games instead used under-playfield-mounted relays instead of TIP36 transistors to power 50 volt coils.
SMIG Board.
There are several generations of sound boards used in DataEast/Sega games. As the games got more advanced, the sound storage requirements grew accordingly. These sound boards are NOT upward or downward compatible.
DataEast/Sega games Checkpoint and later with a dot matrix display have a dot matrix controller board. This board has separate CPU and EPROM chips which only handle the dot matrix score display animations. This CPU is in addition to the CPU board's 6808 (or 6802) CPU chip, which controls the lamps, solenoids, switches, games rules, etc. These boards are NOT upward or downward compatible.
Cabinet Changes. The backbox design changed with Guns N Roses too. The backbox door swings open from hinges on the right hand side (instead of the left). Also the swinging door is easily removable by just disconnecting the two wiring connectors, and pushing the door straight up off the hinge pivot points. Starting with Ninja Turtles, the playfield mounting was changed. Prior to Turtles, the playfields had a single pivot point which allowed the playfield to rotate up vertically. With Turtles and all later games, a playfield slide bracket was implemented. This allowed the entire playfield to be pulled forward about ten inches. This allowed for easy repair to the top portion of the playfield (where the pop bumpers reside, for example). After the playfield is pulled forward, it could then be tilted up vertically against the backbox.
Playfield Glass Sizes (and Wide Body Games).
1f. Getting Started: Game List Here is the list of games and their system generations. This is important to know before beginning troubleshooting and repair.
** This flipper board, if replaced, should be replaced with #520-5076-00. *** This flipper board, if replaced, should be replaced with #520-5080-00. 1g. Getting Started: The Circuit Boards and How they Work
Overview.
Alternating Power Coils/Flashlamps (Multiplexing) One thing DataEast/Sega did consistently was use brown wires for the "L" (or "A") side, and orange wires for the "R" (or "B") side (for power, from the PPB board to the device). Also the "L" side is always the same as the "A" side, and the "R" side is always the same as the "B" side. If the bank select relay is not energized, solenoid power V+ is connected to bank "L". Then only the selected devices can be driven by the driver transistors. There is no power available to bank "R" (usually flashlamps). The "L" bank is usually reserved for coils. When the bank select relay is energized via CPU transistor Q29, solenoid power V+ is connected to bank "R". Then only the selected devices can be driven by the driver transistors. There is no power available to bank "L" (solenoids). The "R" bank is usually reserved for flashlamps.
When the PPB board was implemented on DataEast's third game (Torpedo Alley and later), TIP36c transistors were used to control the high voltage (50 volt) coils. These transistors are usually used in conjuction with the multiplexed TIP122 transistors at Q39 to Q46; the TIP122 transistor acts as a "pre-driver" for the TIP36c transistor (there is even a pre-driver for the TIP122 too). This is done to isolate the CPU logic circuit from the high voltage device. So the TIP36c controls the highest voltage, which is pre-driven by a smaller TIP122, which in turn is pre-driven by an even smaller 2N4401 transistor. Every TIP36c must use a TIP122/TIP102 pre-driver.
Constant Power Coils.
The Six Special Coils (Switched Solenoids). The down side to this was when a pop bumper switch was stuck on, the coil would stay locked on (or "machine gun") and eventually either burn the coil or blow a fuse. This special coil system also required a redundant switch. This switch was part of the switch matrix, and only controlled the scoring for this device.
Fuses for the Special Coils. Eventually DataEast changed their mind on these "special coils", and made them CPU controlled. DataEast referred to the CPU control of these coils as "non-reflexive" circuitry. This means, regardless of how long a solenoid's switch was closed, the solenoid would be energized only once by the CPU, and for a pre-determined time. With this design, when a switch got stuck closed, the coil would not lock on or "machine gun" and burn (or blow a fuse). DataEast implemented this "non-reflexive" circuit with Version 3 of their CPU board (Back to the Future).
Reversal of the L & R Relay Sides. The other problem with this design presents itself when a TIP122 transistor fails (shorts). If any of the related TIP122 transistors short to ground (leaving a permanent ground path for the related device), that "L" side device will lock on (as soon as power is turned on to the game). In the "normal" design, this meant a coil would lock on. This was good; it would be obvious to the operator, and the coil would draw enough power to blow its associated fuse. However with games Time Machine to Simpsons, the "L" side device was as flashlamp. This would lock on the flashlamp, which did not draw enough power to blow its associated fuse. Worse, these flashlamps would get so hot they could melt playfield plastics! DataEast realized the error they made, and corrected the design so the "L" side connected to coils (as done previously), and not flashlamps.
More L/R Relay Problems. This is an incredibly common problem, and is very confusing. This problem is nearly always cold solder joints on the "L/R" relay, on the PPB board. Because this relay (when not energized) defaults to activating the solenoids, any attempt by the game to light a flash lamp (for example, when a game is started), will instead activate the associated solenoid. The flasher paired with the ball popper is supposed to light, but instead another ball gets placed in the shooter lane. DataEast's auto-ball-fire games all have a 'lightning ball' feature which automatically launches a ball in the shooter lane onto the playfield. This gives the instant multi-ball. To fix this, check the L/R relay on the PPB board, and resolder the relay's solder joints.
DataEast's MRB/PPB Playfield Power Boards. There is really no solution for the heat problems either, other than just being aware of the problem and what it causes (potential cold solder joints).
Starting with Playboy, DataEast changed from a traditional two winding flipper coil to a single winding flipper coil. This new "Deger design" flipper coil had only two solder lugs, instead of three. The (normally closed) EOS switch now varied the voltage (from 50 volts to 9 volts) going to the flipper coil, instead of changing the overall resistance of the flipper coil (and using a single high voltage). This made the flipper coil design a bit simpler. DataEast did this in preparation for a solid state flipper design.
The DataEast/Sega Solid State Flipper Board. DataEast/Sega used several different versions of their solid state flipper board. The first version supported just two flippers, and did not use an EOS switch on the flipper coils. Later versions supported two or three flippers and used an EOS switch on the flipper coils. The advantages of this solid state flipper system were many:
Solid State Flipper Board Problems on JP, LAH, TftC.
Easy Damage to the Solid State Flipper board. The best way to avoid damage is to just be careful! When raising the playfield, don't let the playfield get tilted or angled. Also try not to use the playfield prop rod. If it is used, make sure the playfield is straight on the slide rails, and won't fall inside the cabinet.
1h. Getting Started: Using the Internal Adjustments, Audits & Diagnostics
Easy A-Just Diagnostics.
On games before Frankenstein, once in diagnostics, the position of the up/down green button does not matter. The menu items will be stepped through from first to last in sequential order (this was changed for Frankenstein). The position of the green button determines the menu direction the black momentary "step" button will take, either forward or backwards through the menu items. Pressing the black momentary "step" button will move forward through the menu items. If a value is to be changed, press the game's start button. When the desired change is indicated, press the black momentary button to accept the change. To exit the system, hold the black momentary button down. This will quickly scroll past all the other options. When the end is reached, the game will re-boot.
If audits/adjustments is desired, put the green button in the "up" position, and press the black momentary button. Entering changes is the same as described above.
Portals Service Menu.
To modify the green up/down switch into a momentary switch needed for the portals is simple. Just remove the portals switch bracket from the coin door by removing the two phillips head screws that secure it. On the green button will be a silver "C" shaped wire form. Removing this "C" shaped wire form will convert the switch to a momentary style switch. Use the black momentary switch as a reference, as this switch will not have this "C" shaped wire form. This was mentioned in Sega's service bulletin number 74, and can be viewed here and here.
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2a. Before Turning the Game On: Check the Coil Resistance.
Any coil that has locked on (usually due to a short CPU board transistor) will heat up and have a lower total resistance. This happens because the painted enamel insulation on the coil's wire burns, causing the windings to short against each other. This will lower the coil's resistance, causing the coil to get even hotter. Within a minute or so the coil becomes a dead short (less than 2 ohms), and usually blows a fuse. If the CPU board transistor is repaired, and the game is powered on with a dead-shorted coil, this will blow the same driver transistor(s) again when the coil is fired by the game for the first time! There is no sense making more work for yourself. So take 60 seconds and check all the coils' resistance BEFORE powering the game on for the first time. In order to check coil resistance, put your DMM on its lowest resistance setting. Then put the DMM's red and black leads on each coil's lugs. A resistance of 2.5 ohms or greater should be seen. Anything less than 2.5 ohms, and the coil and/or driving transistor may be bad. Now remove the wire from one of the lugs of the coil, and test the coil again. If the resistance is still the same (low), the coil or diode is bad (and also perhaps the driving transistor). If the resistance is higher than 2.5 ohms, the coil is good but the solenoid driver board transistor is shorted and will need to be replaced. Lastly, the coil's 1N4004 diode could be shorted too, giving a false low coil resistance. Cut one diode leg from a coil lug and retest the coil's ohms. Remember when reconnecting the wires to the coil that the power wire (usually two wires or thicker wires) goes to the coil's lug with the BANDED side of the diode attached. The thinner wire is the coil's return path to ground via the driver transistor and attaches to the coil lug with the non-banded side of the diode attached. If a low resistance coil is found, also suspect the associated CPU board transistor as bad. A low resistance coil is a red flag, a warning, that there may be problems on the CPU board. Actually with System11 games, if a low resistance coil is found, I can pretty much guarantee that you will need to (should) replace of course the coil, but also all the silicon devices in its ground path (TIP driver transistor and probably the pre-driver transistor).
2b. Before Turning the Game On: Check the Fuses, Fuse Clips
Most of the fuses for these games are located in the backbox. There can be fuses elsewhere however. For example, on games with solidstate flippers, the flipper power fuses are on the solidstate flipper board, mounted under the playfield on the left side of the cabinet.
Although this does not apply to every DataEast/Sega game, here is a run-down of fuses in many late model games.
Power Supply Board (in backbox). Playfield Power Board (aka PPB, in backbox). Flipper Fuses on the Solid State Flipper Board (aka SSFB, mounted on side of cabinet, under the playfield). Main Cabinet Power Fuses (near the coin door).
DataEast used a less expensive form of fuse holders on their boards. Instead of an actual fuse holder (like Williams used), the fuses are held in place with two metal clips that are soldered to the circuit board. These fuse clips can easily fatique and break. This can cause no connection to the fuse, or intermittent connection. Before ever powering a DataEast/Sega game on, check all the fuse clips. On solid state flipper games (Robocop and later), don't forget to check the flipper board fuse clips too. These use these same cheap fuse clips. The only way to fix the fuse clips is to replace them. Do not try other "hack" type repairs (usually involving soldering the fuse to the broken fuse clip). Just buy new fuse clips and install them, replacing every questionable fuse holder.
Testing Fuses: the Right Way. (Side Note: a "buzz" on the meter means zero resistance. If the DMM doesn't "buzz", either the circuit is OPEN, or the resistance is 100 ohms or greater. If the meter doesn't have a continuity function, just use the lowest resistance setting. A good fuse will measure zero ohms.)
More Reasons to Pull a Fuse from its Holder to Test.
Proper Fuse Clip Tension.
A Failed Backbox Lamp Matrix Fuse Makes DMD Games Look Very Broken. 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.
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 were 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 remains unaffected.
2c. Before Turning the Game On: Burnt Connectors (Power & G.I.)
Square Plug Power Supply Connectors. 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.
Burnt GI Connectors. The GI connectors can get hot and fail. This happens because the molex connectors don't always have enough surface area to handle the GI power requirements. The heat from the connector will cause the solder joints to fatigue which causes resistance (and more heat). The connector pins get so hot they soften the solder. All this causes more resistance, which causes more heat. It doesn't end until the board burns, the fuse heat fatigues and fails, or the connectors pins fall out (or burn!), and open the circuit.
The Flow of the GI Power (GI Failure). Notice all the molex plugs in the above power flow! Each molex plug is a potential problem in the GI power flow, and can (and does) easily burn. Add to this cold solder joints on the GI relay, and bad/cracked fuse holders on the PPB board (see the section above about fatiqued fuse holders), and that is a formula for general illumination failure.
Burnt Transformer Plug.
Fixing a Burnt Connector.
Insulation displacement connector (IDC) plugs are very convenient for an assembly line or automated procedure to install. No wire stripping is needed, the wire is just pushed onto the "V" in the pin, which cuts (displaces) the insulation to make contact with the wire. But they aren't very good in the long run. Many problems with games are attributed to these IDC plugs. A far better connector uses the crimp-on style of pin. A special tool is needed to crimp them, but the reliability will be much higher. Only use crimp-on pin connectors when replacing burnt ones. Help with crimping connectors and lots of other connector info can be found at marvin3m.com/connect. Hand crimping tools include Molex WHT-1921 (part# 11-01-0015), Molex part# 63811-1000, Amp 725, or Radio Shack #64-410 (Radio Shack version is not recommended).
Connector Pins (Trifurcon type). Note Molex sells these pins in "strips" or on a "reel". Do NOT buy connector pins this way! Always buy them in "bags" (separated). It's just too difficult to cut them when they are in strips (sharp scissors do work pretty good for cutting them though). If a good job cutting them is not done, the pins will not insert into their plastic housing correctly. Also always get the tin plated version, NOT the gold plated pins.
Board Mounted Header Pins.
Connector Housings.
Polarized Pegs.
Round Molex Pins.
Burnt GI on Time Machine and Before: Service Bullentin.
GI Over Voltage on Newer DE/Sega/Stern Games. If the GI circuit is run at a lower voltage (like 5.5 to 6.0 volts AC), bulb life goes up dramatically (as much as 10x). To increase bulb life (and decrease heat), the GI voltage from the transformer needs to be reduce. An old trick that Gottlieb did during the 1970s was to use a second GI transformer tap, supplying 5.5 volts AC to the coin door lights only (the rest of the GI for the game got 6.4 volts AC). This ensured that the coin door lights lasted nearly forever. In order to decrease the transformer GI voltage, a bridge rectifier can be used to lower the voltage. This is an old trick that Williams used, and it works really well to lower the voltage by about 1/2 volt. Basically one side of the GI circuit (either the feed or the return) is tied to a bridge rectifier's "+" and "AC" lugs. Then the "+" lug is tied to the "-" lug, and the two "AC" bridge lugs are tied together. This does not rectifier the AC voltage, but does decrease voltage by about 1/2 volt. A heat sink should be used on the bridge too because the bridge can get warm. No additional fuses are required. If the bridge does short internally, the only effect is there's no effect (the AC voltage is no longer decreased by a 1/2 volt).
2d. Before Turning the Game On: Quick and Easy Transistor Testing.
There are a number of TIP122/102 transistors on the DataEast/Sega CPU board: Replace the bad TIP122 transistor(s) with a more robust TIP102 immediately before turning the game on. Replace the associated pre-driver 2N4401 transistor too. 2e. Before Turning the Game On: Relays and Playfield Device Driver Board Problems (Cold/Fatiqued Solder Joints).
Relays. Backbox circuit board relays and their functions:
Replace Relays with the RIGHT Relay!
Wrong PPB Relay installed on some TftC Games.
Playfield Device Driver Boards.
FET Playfield Driver Boards. There were some problems with these FET under-the-playfield boards. On Guns N Roses (the first FET application for DataEast), the game used three playfield magnets to alter the trajectory of the steel pinball. The three magnets were activated by an under-the-playfield board with three FET driver transistors. The FETs had large heatsinks, and were mounted upside down (under the playfield). Often the solder joints on the FETs would crack, causing the magnets to fail or lock-on. Resoldering the fatiqued solder joints fixes this problem. There was another problem with the first generation of FET boards. Instead of the FET driver board being in the backbox close to the CPU board, long wires connecting the CPU data lines to the under-the-playfield FET board were used. This meant any extraneous playfield noise (from the playfield lamps, for example) could cause "interference" on the data lines going to the FET board. On Guns N Roses, this could cause the playfield magnets to lock on, for no apparent reason. There are two solutions to this problem. First, the under-the-playfield FET driver board can be moved to the backbox, and the wires going from the FET board to the CPU board shortened. Then the wires going from the FET board to the playfield device lengthened. This solves the CPU data line noise problem by making the data wires much shorter. The second solution is to use .1 mfd capacitors between the FET board's pull-up resistors and ground to "de-spike" the interference. This solution does not remove the data line noise, but just supresses it at the under-the-playfield FET board. This solution is easier to implement, but it may not totally cure the problem.
2f. Before Turning the Game On: Power Supply Problems (no or low +5 volts).
The +5 volt power supply section is not complicated. Most of the time it's bad (.156" molex) connectors on the power supply board. Aside from that, remember +12 volts D.C. comes from the back box mounted bridge rectifier. Remember this bridge can go open or short, causing low +5 volts or a blown fuse, respectively. If good +12 volts is coming from the backbox mounted bridge rectifier, next check the 2N6057 transistor (replace with a 2N6059). If this does fail or leak, a low +5 volts will be seen. Past that there is a MC1723CP voltage regulator chip too, but this rarely fails. If all these things check out Ok, now check the electrolytic capacitors on the power supply board. These can leak, and corrode the traces on the power supply board underneath them. This is a more common problem then it may seem!
Low-Power Solenoid Voltage Varistor Z1. 2g. Before Turning the Game On: Should the Game be left Powered On?
Although commercial pinball machines can handle being powered on continually, Do not leave homes games turned on when not in use. Here are several reasons:
Leaving a pinball on all the time can cost much more than any potential damage that could be done turning it off and on as needed.
End of DataEast Repair document Part One. * Go to DE/Sega Repair Part Two * Go to DE/Sega Repair Part Three * Go to the Pin Fix-It Index at http://marvin3m.com/fix.htm * Go to Marvin's Marvelous Mechanical Museum at http://marvin3m.com |