Williams System 9 - 11

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1 Introduction

Williams System 9 Board Set

File:System 11 Backbox Boards.JPG

System 11b Board Set in an Earthshaker. The CPU board pictured is upside-down

The Williams system 7 boardset was replaced in 1984 with the system 9 boardset, and then again in 1985 with the system 11 boardset. Combining the driver board, sound board, and cpu directly onto one board eliminated several design deficiencies of the earlier 3-7 boardsets; mainly the 40 pin interconnector, and extra wiring harness interboard connectors. Larger roms could be fitted directly onto the boards allowing for more complex rulesets and sounds.

2 Games

2.1 System 9

Title	Date of Release	Model #	Sound	Other Boards	Notes
Space Shuttle	12-1984	653	C-10716 (Speech only)
Sorcerer	03-1985	532	C-10716 (Speech only)
Comet	06-1985	540	C-10716 (Speech only)

2.2 System 11

Title	Date of Release	Model #	Sound	Other Boards	Notes
High Speed	01-1986	541	C-11030 (Background sound only)
Grand Lizard	04-1986	523	C-11030 (Background sound only)
Road Kings	07-1986	542	D-11197-542 (Background music only)

2.3 System 11a

Title	Date of Release	Model #	Sound	Other Boards	Notes
Pinbot	10-1986	549	D-11297-549 (Background Speech & Sound)
Millionaire	01-1987	555	D-11298-555 (Background Speech & Sound)
F-14 Tomcat	03-1987	554	D-11298-554 (Used on 1st 5,000 games - Background Speech & Sound) / D-11581-554
Fire!	08-1987	556	D-11581-556
Fire! Champagne Edition	09-1987	556	D-11581-556

2.4 System 11b

Title	Date of Release	Model #	Sound	Other Boards	Notes
Big Guns	10-1987	557	D-11581-557
Space Station	12-1987	552	D-11298-552
Cyclone	02-1988	564	D-11581-564
Banzai Run	05-1988	566	D-11581-566
Swords of Fury	06-1988	559	D-11581-559
Taxi	08-1988	553	D-11581-553
Jokerz!	12-1988	567	D-12338-567
Earthshaker	02-1989	568	D-11581-568
Black Knight 2000	04-1989	563	D-11581-585
Transporter the Rescue	04-1989	2008	D-11581-2008
Police Force	08-1989	573	D-11581-573
Elvira and the Party Monsters	10-1989	2011	D-11581-2011
Bad Cats	11-1989	575	D-11581-575
Mousin' Around!	12-1989	2009	D-11581-2009
Whirlwind	01-1990	574	D-11581-574		Uses a C-13287 Sound Overlay Solenoid Board to control 5 extra devices

2.5 System 11c

Title	Date of Release	Model #	Sound	Other Boards	Notes
The Bally Game Show	04-1990	2003	D-11581-2003		Uses a C-13286 Sound Overlay Lamp Board
Pool Sharks	06-1990	2014	D-11581-2014
Rollergames	06-1990	576	D-11581-576
Diner	09-1990	571	D-11581-571
Radical!	09-1990	2015	D-11581-2015
Dr. Dude	11-1990	2016	D-11581-2016
Riverboat Gambler	11-1990	50007	D-11581-50007
Bugs Bunny's Birthday Ball	01-1991	20009	D-11581-20009

Game date of release and model numbers provided by the Internet Pinball Database - http://www.ipdb.org

3 Technical Info

System 9 eliminated a huge issue with the earlier system 3 through 7 boardsets - the 40 pin interconnector used between the MPU and Driver boards. Now, all the circuitry of the mpu, driver, and sound boards was contained on one board. Helper boards were still used for displays, speech, special purposes, and solenoid expansion. Starting with Banzai Run, Williams re-introduced a weak link into their system: the interconnect board, itself designed to eliminate many under playfield flasher driver boards, which had proven themselves problematic.

One of the largest advantages of the system 11 board set is its ability to switch one set of coil driver transistors between 2 sets of coils/flashers. It does this via a relay on a separate board called the A/C relay. The theory is that coils that are seldom fired will be on the A side of the relay, and that flashers will be on the C side of the relay. Most of the time during gameplay, the C side is active, letting the flashers be driven. If the driver transistor for the A/C relay itself is bad, the relay defaults to the coil side, allowing the game continue to operate in a semi-normal fashion (usually the A side coils are the ball shooter lane, drop target resets, VUK - basically coils that don't need to be able to operate 100% of the time like a sling coil or pop bumper coil. (Data East's boardset was essentially a copy of the system 11 boardset - but they programmed it the opposite way, so that the flasher side of the A/C relay is active by default. So on a Data East game when the A/C relay doesn't operate, the game just sits there and flashes lamps instead of playing.)

System 9 and early system 11 games do share a disadvantage with the earlier 3-7 boardsets - they still utilize special solenoid circuitry. The pops and slings on system 9/11 games do not activate a switch which is seen by the mpu's program which fires the coil - instead, the switches directly fire their associated coils via some logic gates on the main board. The main disadvantage with this system is that the solenoids fire continuously as long as their activation switch is closed; a locked on sling or pop will burn out components quickly. It is recommended to add a 1, 1.5, or 2 amp inline fuse to each coil on a directly fired system 11 game. (Usually just the pops and slings are direct fired coils).

3.1 CPU Driver Boards

System 9 CPU

System 11 CPU

Placeholder for System 11A CPU

System 11B CPU

Placeholder for System 11C CPU

3.2 Sound Boards

System 9 Speech Board (from Space Shuttle)

System 9 Speech Board (from Comet)

The speech board used in the first two System 9 games, Space Shuttle and Sorcerer is essentially the same as the speech board used in System 6/7 games. However, the speech board used in Comet has one slight difference. Four jumpers were added to the Comet speech board so either 2532 or 2732 PROMs could be used. Both Space Shuttle and Sorcerer use 2532 PROMs from the factory, while Comet uses 2732 PROMs. The Comet speech board is backward compatible. If using a Comet speech board, either 2532s or 2732s can be used for the first two System 9 games (or System 6/7 games), provided that the jumpers as set for the appropriate EPROM.

In addition to the speech board generating speech sounds, it mixes the sound and speech signals via the potentiometer on the speech board.

Background Sound board as found in High Speed

Background Sound board as found in Pinbot

D-11581 Sound Board, not Completely Populated

File:WilliamsD-11581SoundBoardNotCompletelyPopulated.jpg

D-11581 Sound Board, not Completely Populated

D-11581 Sound Board, Completely Populated

3.3 Power Supply

Pre-Big Guns Power/Regulator Board. This power supply has had the header pins replaced and the 5V filter cap at C10 replaced.

<Note, the description of this PS is not quite correct and needs more research ... Chris>

This power supply uses obsolete parts at Q1 (SDS-201) and Q3 (SDS-202). The PCB print was used through Swords of Fury, with slight modifications. Up until and including Fire! Champagne Edition, Q1 and Q3 were the obsolete SDS-201 and SDS-202. Big Guns was the next game after Fire! Champagne Edition. Big guns and beyond used an MJE15030 at Q1 and an MJE15031 at Q3.

The schematics for this power supply also list part numbers MPSD52 and MPSD02. The equivalent part number for an MPSD52 is a 2N5401. The equivalent part number for an MPSD02 is a 2N5551.

Part numbers printed on an SDS-201 at Q1 may be "6557" or "9057S". Part numbers printed on an SDS-202 at Q3 may be "MDS60" or "9058S"

Big Guns and After Power/Regulator Board

This power supply was used from Taxi thru the remainder of the System 11 board set.

3.4 Auxiliary Power Driver Board

Auxiliary Power Board

3.5 Interconnect Boards

Backbox Interconnect Board

Although the first four System 11B games, which include Big Guns, Space Station, Cyclone, and Banzai Run, use some form of an interconnect board, it wasn't until Swords of Fury when this interconnect board was used as a standard for the remaining System 11 games. The interconnect board used in Swords of Fury does use a different part number, D-12185-559, compared to later System 11 games, D-12313-x (x denotes the game's model number), but it is nearly the same in design.

The interconnect board is located in the backbox, just below the CPU board. The board has the following circuits passing through the board:

• the lamp general illumination circuits
• flipper power and ground
• lamp columns and rows
• switch columns and rows
• flash lamp power

What differentiates the board from game to game are the resistor and fuse values used for the flash lamp power circuits.

3.6 Other Boards

3.6.1 Sound Overlay Board (C-13287)

Williams "C-13287 Sound Overlay Solenoid Board" as found in WhirlWind

This relatively simple board was used on Whirlwind only to accommodate 5 additional solenoids (flashers or motors). The board logically sits between the System 11 MPU and the sound board, intercepting data normally sent directly to the sound board, and acting on that data only when specific codes are commanded. The board also relays data not specifically intended for it, on to the sound board.

3.6.2 High Current Driver Boards

Williams C-12493 High Current Driver Board from Earthshaker

The high current driver board was used on Earthshaker to drive the shaker motor. It was used on several other Williams / Bally WPC under multiple part numbers.

3.6.3 A/C Relay

Placeholder for A/C relay board (early design ie. F-14, Pinbot)

Placeholder for A/C relay board (later design)

Starting with Road Kings, System 11 games make use of what is referred to as an A/C relay. The purpose of the A/C relay was to drive twice the amount of coils and flashers by using half the amount of drive transistors. This process is commonly referred to as "multiplexing". Typically, if the A/C relay was at rest, the "A side" flashers would engage. When the A/C relay was powered, the "C side" solenoids would engage.

For example, High Speed, which does not use an A/C relay, uses 8 discrete drive transistors to drive solenoids / flashers 1-8. Pinbot, which does use an A/C relay, uses the same 8 discrete transistors to drive solenoids / flashers. However, a total of 16 solenoids and flashers (A side and C side) are driven. By employing the use of an A/C relay, the System 11 MPU / driver board could be used for many more years without a "drastic" redesign.

Initially, the A/C relay was located on a small circuit board under the playfield for System 11/11A games. Likewise, this A/C relay board did not have Molex header connections. Wires were directly soldered to the circuit board. Once the Auxiliary Power Driver Board was introduced with the System 11B platform (starting with Big Guns), the A/C relay was moved to this board for all subsequent System 11B/11C games.

3.7 Flipper Coils

System 11 games (starting with F-14 Tomcat) use different flipper coils dependent on flipper placement and application. Below is a chart of the flipper coils used, their wrapper color, and strength.

System 11 Flipper Coils
Part #	Color	Strength	Notes
FL-11753	Yellow	Weakest
FL-11722	Green	Weaker
FL-11630	Red	Standard
FL-11629	Blue	Strongest

4 Problems and Solutions

4.1 Power Problems

Replacement power supply If using the Rottendog WDP011A power supply for Williams Cyclone or Big Guns, you may have to move the +12v jumper from the bottom jump to the top. If your machine has GI but doesn't boot (only the 5v light on the CPU is lit) and is one of these two games, that is the most likely reason.

Bridge Rectifier Fuses A design flaw carried over from the earlier systems was the lack of fuses on the two bridge rectifiers used for the solenoid and lamp power. In theory, if either of these bridges short, the main power fuse in the game will blow, but that's not always the case. On games before Fire, interrupt one of the AC input lines and install a fuse holder with an 8 amp fuse installed. Games made after Fire already have a factory installed fuse holder and fuse on these bridges.

4.2 MPU boot issues

4.2.1 Normal Game Boot Behavior

The 7-Segment diagnostic display on a System 11(nothing) MPU.

Normal MPU boot behavior for games with a 7-segment display on the MPU is to show a "0" in the display. The "0" does not go away. The "0" will continue to be displayed under normal boot conditions.

+5 VDC, Diagnostics, and Blanking LEDs as found on a System 11A, 11B, and 11C MPUs.

Normal MPU boot behavior for games with 3 LEDs instead of the 7-segment display on the MPU is for the "+5 VDC" LED to light first and stay on, then a split second later, the blanking LED will light and stay on. At the same time that the blanking LED lights, the diagnostic LED will begin to blink at a fairly rapid pace with a 50% duty cycle (equal durations of the LED being on then off).

+5 VDC, Diagnostics, and Blanking LEDs driven by game software expecting a 7-segment display as in High Speed.

If a System 11 MPU with 3 LEDs is installed in a game whose original board contained the 7-segment LED diagnostic display first introduced with the System 7 board set, the status of the 3 LEDs won't help much. The game software is attempting to display a "0" (assuming your game boots correctly) on a 7-segment display. Since the board contains just the three LEDs, the MPU circuitry merely lights all three LEDs as shown in the picture at left.

4.2.2 MPU Boot Error Codes

MPUs used in System 11(nothing) games display a code on a 7-segment display if an error is detected during boot. MPUs used in System 11A, 11B, and 11C games use the Diagnostic LED to blink a "codes".

4.2.2.1 System 11(nothing) games

The following table lists the error codes displayed on the System 11(nothing) MPU 7-segment display.

Code	Description
0	Normal game boot with no problems detected. The game should be in attract mode.
1	CPU board locked up. Possible cause is memory protect circuit and U25 CMOS RAM "stuck bits".  That is, an actual failure of the CMOS RAM chip or the 6802 processors ability to communicate error free with the RAM.
2	U27 Game ROM checksum failure
3	U26 Game ROM checksum failure
4	not used
5	Blanking signal "stuck", or the coin door is closed, or the memory protect circuit is faulty, or the CMOS RAM at U25 has failed.
Other or no indication	General system failure. Check the 5VDC power supply as well as the integrity of game ROM 2 at U26.

A zero displayed during Memory Chip Test (using the CPU board switch SW2) indicates that the blanking circuit is NOT functioning properly.

An eight displayed during memory chip test (using the CPU board switch SW2) indicates that the blanking circuit is functioning properly.

4.2.2.2 System 11A, 11B, 11C games

The following table lists the number of blinks, the error message that might be displayed, and the explanation (Source: Williams System 11A game manual. with embellishment).

Code	Description
0	no message	Normal game boot with no problems detected. The game should be in attract mode.
1	U25 RAM FAILURE	The RAM at U25 could not be used properly. This means that the RAM failed a read/write test at power up.  The game will remain in the current state and no other tests are performed until the game is turned off, then back on.
2	MEM. PROT. FAILURE	This message means that either:    a) the Coin Door may be shot,    b) the Memory Protect Switch may be stuck in the ON position,    c) the memory protect logic is protecting the memory, or    d) a U25 RAM failure is occurring.
3	U51 PIA FAILURE	The PIA at U51 has failed.
4	U38 PIA FAILURE	The PIA at U38 has failed.
5	U41 PIA FAILURE	The PIA at U41 has failed.
6	U42 PIA FAILURE	The PIA at U42 has failed.
7	U54 PIA FAILURE	The PIA at U54 has failed.
8	U10 PIA FAILURE	The PIA at U10 has failed.
9	IRQ FAILURE	The interrupt request line is not working normally. It may be missing, stuck, too fast, or too slow.
10	U27 ROM FAILURE	U27 failed checksum (test 11 is skipped).
11	U26 ROM FAILURE	U26 failed checksum.

All of the above failures (except #9) may mean that the device has failed but it may also mean that the 6802 microprocessor is unable to communicate adequately or properly with the device. For example, if the CPU is attempting to checksum the game ROM at U27, but one of the 8 data lines leading to U27 has been severed, the wrong data will be received by the microprocessor and the checksum test will fail even though the ROM is perfectly fine.

4.2.2.3 Five "Knocks"

Sometimes when turning a system 11 game on, the knocker will fire 5 times, causing most folks to wonder, "what the hey"?. All that knocking is designed to call the operators attention to a potential switch issue. Like the "credit dot" in WPC games, these 5 knocks mean that the game hasn't detected the closure of a particular switch (or switches) in a certain number of games. A message will be displayed indicating which switch or switches to examine.

Usually, this is an indication of a failed switch. Most switches get closed during the normal course of game play, long before the game's software counts up to the limit of "games played without closing each switch" and issues this indication.

To address this issue, use the coin door diagnostic panel buttons to enter switch edge test. Manually close the switch. If a switch closure is indicated, either normal game play failed to close the switch (you're not a very good player), or the switch is dirty. Closing a switch with your finger is different than closing a switch with a ball. Your finger generally pushes more firmly on the switch contacts. Clean the switch by dragging an old business card or piece of paper between the switch contacts while pinching the switch blades together with your fingers.

Caution: do not attempt to adjust switches with anything metal while the game is turned on. You will eventually short coil or lamp power to the switch matrix, damaging the MPUs switch matrix circuitry.

If closing the switch manually doesn't register in switch edge test, see the "switch problems" section of this Wiki.

4.2.2.4 System 11 "Adjust Failure" and "Factory Setting"

The typical "Adjust Failure" message on a System 11 game, coin door closed.

The "Adjust Failure" message seen in the picture at left occurs when the game software can't make sense of the information contained in the battery backed RAM at U25. This could be because the RAM has failed, but this is unlikely. The vastly more common reason is that battery backup power has been interrupted to the games battery backed RAM because either the batteries are not installed, dead, or dieing. Hopefully, they haven't made a mess of the board by leaking alkaline. See below. "Adjust Failure" is displayed under these conditions when the coin door is closed.

The typical "Factory Setting" message on a System 11 game, coin door open.

If the coin door is open under these conditions, the message "Factory Setting" is displayed.

4.2.3 Relocating the battery from the System 9 MPU board

Leaking Battery

Relocating the 3xAA batteries off the MPU board is always a good idea. Leaky alkaline batteries are the #1 killer of pinball boards. Sometimes the battery terminals don't look corroded, but the metal rivet which contacts the battery are actually missing.

If "04 00" in the credit/match display is seen when the game is turned on, the game is in audit mode versus attract mode. Below are several reasons why the game has defaulted to audit mode.

• The batteries have failed and need replacing.
• The battery voltage is not reaching the U18 (5517-2) RAM. Check pin 24 of U18 for approximately 4.3v with the power on and 3.9v with the power off. Lack of battery backup power could also be due to an open D3 (1N4148) blocking diode. This diode is used to keep the CPU's logic power from charging the batteries.
• Blocking diode D2 (1N5817) has shorted, and the batteries are trying to run the MPU board when the game is off.
• There are other problems, such as a faulty 5517-2 RAM.

Simply removing the batteries will not allow a game to boot directly into "attract mode" when switched on. It also will not retain the settings such as the number of balls per game, the free play setting (obtained by setting maximum credits to 0), or high scores. However, a System 9 game will boot, and is still playable with the lack of batteries. To complete the boot sequence into attract mode, open the coin door, switch the game off, and then quickly back on. The game should leave audit mode, and go into attract mode. Credits would need to be added from the coin door, and if necessary, settings would need to be changed before starting a game.

The best option is to remotely locate the battery holder somewhere below all the other boards. This ensures that even if the remotely located batteries leak, they won't leak onto (or even drip onto) components of the MPU board. Use good quality alkaline batteries, mark the date of replacement with a Sharpie, and replace the batteries annually.

Adding a connector between the battery pack and the MPU board is a good idea. You can easily remove the battery pack from the board. Plus, if the batteries are forgotten, and do leak, the MPU board will not have to be removed to add another battery pack. A 3 x AA battery holder is the typical recommended replacement. If only a 4 x AA battery holder is available, a jumper can be soldered in the first battery position. Likewise, a diode can be placed in this position instead. This will prevent the batteries from being charged and 'cooked' by the game if blocking diode D3 on the MPU board fails. Keep in mind that adding a secondary diode to this circuit will decrease the voltage passing to the RAM memory by .5 to .7 volts (the typical voltage drop across a diode) if D3 is still good. Install a 1n4001 or 1N4004 diode in the position closest to the last + terminal (where the Red Wire exits). The banded side of the diode must be pointing in the direction of current flow, which is towards the (+) terminal marking on the MPU board, and away from the battery pack.

Williams System 9 MPU Board

On the System 9 MPU, solder the battery cables: Ground (Black Wire) to the Bottom Left pad and Positive (Red Wire) to the Top Right.

After adding a remote battery pack, and while the board is still out of the game, it is a good practice to measure the battery pack's voltage at the (+) and (-) pads of the MPU board. All battery packs are pretty cheaply made, and failures "out of the box" are somewhat common. Checking to make certain the battery pack is functioning before reinstalling the MPU board in the game will save you some headaches.

D2 and D3 Diodes Highlighted on a Williams System 9 MPU Board

Since the MPU board is already out, another good practice is to check the D3 blocking diode. An open blocking diode will not allow the battery pack voltage to pass through to the non-volatile memory, and the newly installed battery pack will be ineffective. Conversely, a shorted blocking diode will allow the board's +5vdc logic power bus to pass through to the battery pack. This in turn, will charge the batteries, while the game is turned on. Alkaline batteries do not like being charged. They will heat up, and fail prematurely, (rather quickly). In worse cases, the new batteries can even leak or explode if charged. Testing the D3 diode is quick and easy, and worth the trouble checking it out. When in doubt, replace the D3 diode with a 1N4148, or add a secondary 1N4004 to the battery pack. Once again, if a secondary diode is added, it will decrease the voltage passing to the 5517-2 RAM memory, if D3 is still good.

4.2.4 Relocating the battery from the System 11 MPU board

A remote battery holder installed on a System 11 MPU. The purple wire is positive.

4.2.5 Installing NVRAM instead of batteries

Like most other pinball mpu boards, you can replace the battery-backed ram with a non-volatile memory ram. Unlike most other systems, you have to jumper around a diode so the game will boot. D1, a 1n5817 diode, has a very low forward voltage drop (about 0.2 volts) vs. the normal 0.4-0.6 volts most other diodes have. If you replace U25 with the memory ram, most memory ram will not unlock and allow writes until the voltage is 4.8 volts or so. The 1n5817 D1 diode is just enough to prevent most memory rams from allowing writes. To solve this, solder a jumper wire around the D1 terminals, or remove D1 entirely and replace with a jumper. Make sure you do not have batteries installed if you do this as they will simply short to ground, get hot, and leak. It's recommended to remove D2 and the battery holder entirely if you do this so this will never be a possibility, and write with a sharpie where the battery holder was "upgraded to NVRAM".

You need a replacement ram that can replace a 6116 or a 6264. These are becoming scarce, but there are other solutions available that use surface mount equivalents on a small circuit board that plugs into the RAM's socket. Unfortunately, U25 is soldered in on most system 11 boards and would need to be removed to replace with an NVRAM.

4.2.6 Installing a memory capacitor instead of batteries

A 5.5 volt 1.5 farad capacitor can be installed in place of batteries. To do so, remove the battery holder and install the + lead of the memory capacitor bent into a dogleg shape in the + hole that feeds diode D2. (The memory cap should be mounted slightly off the board. This is the purpose of the dogleg bend, but if you have a mica insulator that will work also.) Fold the - lead on the capacitor flat and solder a small jumper wire to it that goes to the main negative terminal where the battery holder was; this is diagonally opposite the + lead in most cases, but double check with a meter. Make sure you heat shrink this connection so it doesn't short out against any traces or pads in the area.

To allow the capacitor to charge, you need to jumper around diode D2, or remove it entirely and replace with a jumper wire. A full charge may take 8-12 hours, but once the memory capacitor is charged, turning the machine on for about 30 minutes a month is enough to keep the capacitor charged up.

4.2.7 Repairing Alkaline Corrosion

Remove the battery holder entirely from the MPU board and wash the board's affected areas with a 50/50 mix of vinegar and water. Scrub the corrosion with a soft toothbrush, rinse with water, then rinse with 91% or 99% isopropyl alcohol to displace the water. Unfortunately on system 11 boards often the corrosion will eat into traces that are beneath PIA chips (U41/U42) requiring desoldering of those chips to remove the corrosion and repair traces.

4.2.9 Using a PC Power Supply For Bench Testing

System 9 CPU connected to a PC power supply

4.3 Game resets

System 9/11 games are far more tolerant of low line conditions vs. the newer WPC games. Some things to check if the game is resetting are the usual culprits for this type of thing: connectors, filter capacitors, slam switches, bad chip sockets, etc. It is good preventative maintenance to replace the +5 volt filter capacitor on the power supply with a new one; most of these are between 20-26 years old and might be getting to the point of wearing out. Certainly replace them if you are getting resetting on your system 11 game.

Most system 11 games give an indication that they've been slam tilted; if you're getting a "game reset" but you get a noise and/or a message on the displays beforehand, it is probably a slam switch issue vs. a true reset issue. Check all the slam switches in the game (usually the coin door is the main one, and also the ball roll tilt if present).

4.4 Solenoid problems

this is a stub

4.4.1 A/C solenoid/flasher problems

There are a couple ways for the A/C circuit to fail. If the driving transistor (Q8) for the relay shorts, for the most part flashers will fire instead of coils. If the driving transistor never fires, coils will dominate instead of flashers. Testing this behavior is easy. Use the diagnostic buttons to select solenoid test mode, and watch carefully to see what fires. The display will show the coil/flasher under test. If the A/C select circuit is not working, any A/C selected transistor will fire the same item twice in a row.

The A/C relay is solenoid 12 in the tests - during this test selecting 'repeat' for the solenoid test should result in hearing the A/C relay click on and off repeatedly.

If all of 'one side' of the A/C is not working, suspect either the fuse supplying the voltage to that side of being blown or the relay terminals needing resoldering. The relay is relatively heavy and its weight puts stress on its soldered connection to the auxiliary power board.

It is rare to have the A/C relay itself go bad. Possible failure points on the relay itself are the miniature contacts on the relay wipers; these are high power, high current contacts that can be cleaned (filed) with a small points file to restore proper current carrying capacity. Under no circumstances use contact cleaner on these contacts, as they are high voltage and could cause a spark/fire to occur. Do not mangle the contact wipers in an attempt to adjust them; use great care if you decide to adjust these. It is not needed in 99% of the time to adjust them.

Another failure point are the connectors and headers connecting the aux driver board to the main cpu/driver board. Any cracked header can affect the proper operation of the relay. It is good practice to replace or at minimum resolder header pins, and to replace connector pins in their housings with new pins. System 11 machines use 0.156 sized connectors in most locations.

4.4.2 Special solenoid problems

Special solenoids on system 11 games are similar to the earlier variants used on all previous Williams' baordsets. During gameplay/test modes the primary switches on the special solenoids (usually the pops and slings) are active, allowing actuation of those switches to fire the solenoids. This is done by grounding an input to a 7402 logic chip which in turn pre-drives a 2n4401 pre-driver transistor which drives a TIP122 darlington transistor to fire the solenoid.

During solenoid test mode only, the secondary path to the 7402 is utilized instead to fire the solenoids. Since there are 2 paths to fire the solenoids, it is possible for a special solenoid to work in game/test mode, but fail the solenoid test due to a failed PIA or 7402 chip, and vice-versa.

If a special solenoid actuation switch locks on, the solenoid itself will lock on as well, (hopefully) blowing the associated fuse before blowing the Tip122/2n4401/7402 grounding chain. An inline fuse holder can be added to all special solenoids with a 1 amp fuse installed to help prevent this situation.

There is a 22uF non-polarized capacitor and a 100 ohm resistor mounted across the special solenoid switches. The use of the capacitor and resistor creates what is called an RC circuit. The RC circuit is used to filter noise from the switch signal. Should a special solenoid lock on, and the switch leaves are properly gapped, the issue may be a shorted switch capacitor or resistor.

Later system 11 games do not use the special solenoids in the same way. They were changed to a cpu polled switch instead, keeping all the solenoid pulses under cpu control. You can easily tell if your game has the cpu controlled type by inspecting the activation switches on the pops and slings; if there are a primary and secondary switch installed, it is a direct-fire special solenoid setup. (Note that secondary switch in the case of slingshots does not mean the normal 2nd switch all slings shots employ; rather, it refers to a switch that only activates when the sling activates. It is installed near the pivot point of the sling arm underneath the playfield.)

4.5 Lamp problems

4.5.1 Lamp Matrix Row and Column Testing

The CPU logic for the lamp matrix can be tested by connecting a spare lamp using a jumper wire. The following sections show the separate procedures for testing the switch matrix columns and rows. The example is on a Sys11A PinBot, but applies to all Sys11 CPU boards.

Testing the lamp matrix columns:

Jumper connection for testing lamp matrix columns.

Use the following procedure to test the TIP42 transistors that drive the lamp matrix columns. Note that a diode is not needed for these tests since it's function is to prevent interaction between the lamps in the matrix. In this test we are only connecting a single lamp at a time.

1. Remove the backglass and open the insert to get access to CPU board connectors 1J6 (row) and 1J7 (column).
2. Unplug connectors 1J6 and 1J7 (lower right corner of CPU board)
3. Turn the game on and go to the "All Lamps" test in the Test/Diagnostic Menu. This is done by opening the coin door an pressing: MANUAL-DOWN, ADVANCE, AUTO-UP, ADVANCE x 2
4. Clip one end of the test jumper to 1J6 pin 1, the rightmost pin on the connector
5. Touch the other end of the jumper to 1J7 pin 1, the rightmost pin on the connector
6. The test lamp should flash to indicate that the column driver is working.
7. Repeat the test for the pins 2 through 9 on 1J7. There is no pin 5 as it is the key.

If a column doesn't light or is stuck on, reference the lamp matrix table in the manual to identify the transistor to test.

The following table shows the lamp number and driving transistor for each of the column pins.

Pin	Wire Colors	Lamp number	Transistor number
1J7-1	Yel-Brn	1	Q66
1J7-2	Yel-Red	9	Q64
1J7-3	Yel-Orn	17	Q62
1J7-4	Yel-Blk	25	Q60
1J7-6	Yel-Brn	33	Q58
1J7-7	Yel-Blu	41	Q56
1J7-8	Yel-Vio	49	Q54
1J7-9	Yel-Gry	57	Q52

Testing the lamp matrix rows:

Jumper connection for testing lamp matrix rows.

Use the following procedure to test the TIP102/122 transistors that drive the lamp matrix rows.

1. Remove the backglass and open the insert to get access to CPU board connectors 1J6 (row) and 1J7 (column).
2. Unplug connectors 1J6 and 1J7 (lower right corner of CPU board)
3. Turn the game on and go to the "All Lamps" test in the Test/Diagnostic Menu. This is done by opening the coin door an pressing: MANUAL-DOWN, ADVANCE, AUTO-UP, ADVANCE x 2
4. Clip one end of the test jumper to 1J7 pin 1, the rightmost pin on the connector
5. Touch the other end of the jumper to 1J6 pin 1, the rightmost pin on the connector
6. The test lamp should flash to indicate that the column driver is working.
7. Repeat the test for the pins 2 through 9 on 1J6. There is no pin 4 as it is the key.

If a row doesn't light or is stuck on, reference the lamp matrix table in the manual to identify the transistor to test.� The following table shows the lamp number and driving transistor for each of the row pins.

Pin	Wire Colors	Lamp number	Transistor number
1J6-1	Red-Brn	1	Q80
1J6-2	Red-Blk	2	Q81
1J6-3	Red-Orn	3	Q82
1J6-5	Red-Yel	4	Q83
1J6-6	Red-Grn	5	Q84
1J6-7	Red-Blu	6	Q85
1J6-8	Red-Vio	7	Q86
1J6-9	Red-Gry	8	Q87

4.6 Switch problems

4.6.1 Switch Matrix Row and Column Testing

The CPU logic for the switch matrix can be tested by simulating switch closures using a jumper wire. The following sections show the separate procedures for testing the switch matrix columns and rows. The example is on a Sys11A PinBot, but applies to all Sys11 CPU boards.

Testing the switch matrix columns:

Jumper connection for testing switch matrix columns. This picture shows a diode which is not necessary for this test.

1. Remove the backglass and open the insert to get access to CPU board connectors 1J8 (column) and 1J10 (row).
2. Turn the game on and go to the "Switch Edges" test in the Test/Diagnostic Menu. This is done by opening the coin door an pressing: MANUAL-DOWN, ADVANCE, AUTO-UP, ADVANCE x 6
3. Unplug connectors 1J8 and 1J10
4. Clip one end of the test jumper to 1J10 pin 9, the leftmost pin on the connector
5. Touch the other end of the jumper to 1J8 pin 1, the rightmost pin on the connector
6. The display should report that switch 1 was actuated. The test may report the switch name, refer to the switch matrix table in the manual to correlate the name to the switch number.
7. Move the jumper to 1J8 pin 2 and check the reported switch by comparing to row 1 in the switch matrix table
8. Continue to test the rest of the pins on 1J8. There is no pin 6 as it is the key.

The following table shows the switch number that should be reported for each of the column pins.

Pin	Wire Colors	Switch number
1J8-1	Grn-Brn	1
1J8-2	Grn-Red	9
1J8-3	Grn-Orn	17
1J8-4	Grn-Yel	25
1J8-5	Grn-Blk	33
1J8-7	Grn-Blu	41
1J8-8	Grn-Vio	49
1J8-9	Grn-Gry	57

Testing the switch matrix rows:

Jumper connection for testing switch matrix rows. This picture shows a diode which is not necessary for this test.

1. Remove the backglass and open the insert to get access to CPU board connectors 1J8 (column) and 1J10 (row).
2. Turn the game on and go to the "Switch Edges" test in the Test/Diagnostic Menu. This is done by opening the coin door an pressing: MANUAL-DOWN, ADVANCE, AUTO-UP, ADVANCE x 6
3. Unplug connectors 1J8 and 1J10
4. Clip one end of the test jumper to 1J8 pin 1, the rightmost pin on the connector
5. Touch the other end of the jumper to 1J10 pin 1, the rightmost pin on the connector
6. The display should report that switch 1 was actuated
7. Move the jumper to 1J10 pin 2 and check the reported switch by comparing to column 1 in the switch matrix table
8. Continue to test the rest of the pins on 1J10. There is no pin 4 as it is the key.

The following table shows the switch number that should be reported for each of the row pins.

Pin	Wire Colors	Switch number
1J10-9	Wht-Brn	1
1J10-8	Wht-Red	2
1J10-7	Wht-Orn	3
1J10-6	Wht-Yel	4
1J10-5	Wht-Blk	5
1J10-3	Wht-Blu	6
1J10-2	Wht-Vio	7
1J10-1	Wht-Gry	8

4.7 Display problems

System 9/11 High Voltage Section Repair

WARNING: This circuit uses high voltages. Don't continue, unless you are confident in your diagnostic abilities.

Check Voltages

If all displays are blank, your high voltage (HV) section may not be working. On the Power Supply Board, use a DMM set to DC volts with the - lead grounded, probe the following connector pins to determine if the HV section needs repair. If the display fuse, F1 is blowing, you should remove the applicable display connector (with power off) before testing the voltages.

If you have Power Supply D-11883 or D-12246:

3J2 pin 1 = -100 volts DC
3J2 pin 3 = +100 volts DC

If you have Power Supply D-8345-xxx:

3J5 pin 3 = -100 volts DC
3J5 pin 4 = +100 volts DC

If the test points are more than about 5 volts out of spec, then your HV section may be malfunctioning (if you or a previous owner replaced Z2/Z4 with 1N4763A diodes to purposely reduce the display voltage, test readings in the 90's range would be normal).

Check the table below for a solution.

Troubleshooting table

Symptom	Possible Cause	Replacement
0V ON BOTH +100/-100 lines	Check F1	1/4 Amp SB
0V on +100V line	Open Diode D3	1N4004
	Open Q2	2N5401
	Shorted Zeners ZR1, ZR2	1N4730A and 1N4763A
	Open Q1	MJE340
	Open R1	39k ohm, at least 1 watt
0V on -100V line	Open Diode D4	1N4004
	Open Q4	2N5551
	Shorted Zeners ZR3, ZR4	1N4730A and 1N4763A
	Open Q3	MJE350
	Open R4	39k ohm, at least 1 watt
F1 1/4 Amp Fuse Blows	Bad Capacitor at C1 and C3	100uF,150V
	Shorted Display	Display Glass*
	Shorted UDN7180	UDN7180*
	Shorted UDN6118	UDN6118*
+118V on +100V line	Shorted Q1	MJE340
-118V on -100V line	Shorted Q2	MJE350
* located on display board

Display Fuse F1 Blows

Testing the UDN Chips

If the display fuse is blowing, you should check the display board for shorts before connecting a new or rebuilt power supply to the display board, as a shorted display or chip can damage a good power supply. Remove the display board from the system. The display characters are driven by the two types of UDN chips, the UDN7180 & UDN6118 (or UDN6184). Locate these chips (there are several) on the board and test them with your DMM set to diode check. Clip your + (RED) lead to the ground trace of the board. Probe the UDN chips as shown in the diagram. If any shorts are read in the tested pins, the display should not be connected to the power supply until the shorts are corrected.

Shorts Are Found in UDN Chip Test
If a short reading is found in the tested pins (don't test the pins labeled 'dont care'), the UDN chip should carefully be desoldered and removed from the board. Take care to preserve this chip, as they are nearly impossible to find and expensive to replace. Now install an IC socket in its place. Repeat the test with no chip installed. If the short is gone, then the UDN chip needs to be replaced. If the short remains, then the display glass needs to be replaced.

Displays Test With no Shorts
Once the displays are tested and shorts are eliminated, we can proceed with the HV section repair.

Replacing the components in the HV Section
Since there are not that many components, if you are having problems isolating the fault, a quick solution is to replace all the components in the HV section. If only one side (+ or -) is failing, it is possible to rebuild only the failing side. Check the parts section of the wiki to find suppliers, and get the replacement parts for one or both failing sides:

Part	+Side Part	-Side Part	+,-Location
Transistor	MJE340 (or MJE15030)	MJE350 (or MJE15031)	Q1,Q3
Transistor	2N5401	2N5551	Q2,Q4
Zener diode	1N4730A	1N4730A	Z1,Z3
Zener diode	1N4763A**	1N4763A**	Z2,Z4
Resistor	39k Ohm,1W	39k Ohm,1W	R1,R4
Resistor	680 Ohm,1/4W	680 Ohm,1/4W	R2,R5
Resistor	330k Ohm,1/2W	330k Ohm,1/2W	R3,R6
Capacitor	0.1uF,250V metal polyester	0.1uF,250V metal polyester	C2,C4
Capacitor	100uF,150V	100uF,150V	C1,C3
**This is a 91V Zener to reduce the voltage to prolong display life

Remove and replace HV components

• Clip the old components from the board (make sure you have new ones first).
• Use one of the desoldering methods to remove solder from the holes.
• Stuff board with new components.
• Check for correct orientation on transistors, diodes and the large capacitor if you replace it.
• Leave a little space under components for air flow.
• Bend leads on components so they won't fall out when board is inverted for soldering.
• Double check that all the correct parts are in the correct places and properly oriented.
• Solder the parts to the board
• Clip excess off leads

NOTE ON INSTALLATION OF THE MJE340/MJE350 TRANSISTOR
The MJE340/MJE350 is the heat-sinked transistor. On most Williams boards, this transistor pin configuration is not the same as the original part. It will need to be installed vertically with heat sink attached to the transistor only. The transistor will sit at about a 45 degree angle so the legs can be lined up to fit in the correct holes.

Check your board and insure correct orientation before soldering in place. Late versions of the System 11 series boards were designed to use the pin configuration of the MJE340/MJE350 transistors.

Do not mount vertically if the power supply is designed to use the pin configurations of the newer transistors!

NOTE: The MJE15030/MJE15031 are rated for higher power and can be used instead of the MJE340/MJE350, but the MJE340/MJE350 are well within design specifications and are suitable replacements at 1/3 the cost of the MJE15030/MJE15031.

Ready to test

To test the rebuilt power supply, return to the "Check Voltages" section of this guide.

Other Resources
The System 9-11 HV section of the PSU is very similar in design to the earlier System 3-7. So it will be worth reading through the Sys 3-7 PSU Problems section entitled +/-100v Display HV Section of PSU, for some more detail. It also provides links to source complete HV rebuild kits which will normally cost under $10 shipped.

4.7.1 Replacing Display Glass

Replacement glass installed with glass nipple in proper location

Replacement glass installed after circuit board was drilled to allow for glass nipple in different location

All plasma displays have a finite life expectancy. Display glass replacements were and are offered in several configurations. The differences in these configurations are mainly the placement or lack of a display "nipple" on the back of the glass. The glass nipple is what can pose as somewhat of a problem, when replacing a display glass. Williams did place a rather large hole in the display circuit board. However, the placement of the glass nipple has changed. To overcome this issue, a hole can carefully be drilled through the circuit board to allow for the glass nipple. When drilling, drill successive holes, starting with a small drill bit first, rather than drilling one large hole. This will reduce the chances of the circuit board "splintering".

4.8 Sound problems

4.8.1 System 9

4.8.1.1 Jumper Settings for a Comet System 9 Speech Board

Jumpers Circled on a Comet System 9 Speech Board

As mentioned above, the System 9 speech board is essentially the same as the System 6/7 speech board. However, the Comet speech board has jumpers added to increase the flexibility of PROMs used. Either 2532 or 2732 EPROMs can be used. If using 2532 PROMs, install jumpers W2 and W4, and remove jumpers W1 and W3. If using 2732 EPROMs, install jumpers W1 and W3, and remove jumpers W2 and W4.

4.8.1.2 Missing Sound or Speech Calls

To start a sound test, simply press the SW2 momentary switch at the bottom of the CPU board located between connections 1J16 and 1J17. Once SW2 is pressed, the CPU will cycle through all of the sound / speech calls continuously. Each System 9 game has a chart located in the manual, which lists the speech and sound calls made during test. The benefit of the chart in the manual is that it lists the ROM where a particular call originates. If a particular sound / speech call is not heard, the associated ROM listed for that call may be bad.

4.8.1.3 Isolating the CPU Sound from the Speech Board

Some of the sound / speech calls originate from the CPU board, while the remaining calls originate from the speech board. If after running a game through sound test by pressing SW2, and some sounds are missing or very low in volume, a good idea is to isolate the CPU board from the speech board. All of the sounds originated on the CPU board, leave the board via the 40 pin ribbon cable, and go to the speech board for mixing. Once mixed, all of the sounds and speech are then returned to the CPU board, amplified, and sent out to the speakers.

Much like the System 6/7 sound and speech boards, the sound can be isolated from the speech board for testing purposes. The System 6/7 Type 2 sound board uses a jumper at position W1. When jumper W1 is installed, the sound board can be diagnosed without the speech board installed. The equivalent with the System 9 CPU board is jumper W10. This jumper is typically not connected. However, when it is connected, the sounds originating from the CPU board can be heard.

Locate jumper W10 on the CPU board. W10 is located to the right of SW2 on the board. There should be two very small wires clipped on either side of W10, as if W10 was installed and removed. With a alligator test lead, connect each alligator clip to the short leads of W10. If the short leads are not present, a short light gauge wire or wire wrap can be tack soldered to the solder pads of W10. With a jumper installed at W10, some sounds should be heard when SW2 is pressed. If no sounds are heard, further troubleshooting must be performed.

• Jumpering W10 on a System 9 CPU Board
• 

  Locating jumper W10
• 

  Temporarily jumpering W10

4.8.2 System 11

System 11 games are known to have some amount of hum present in the sound. To minimize this interference, make sure all boards are secured tightly with all screws installed. This will insure the boards have a proper ground.

Another cause of hum could be an inconsistent +5 volts from the power driver board. An indicator of this being the cause of your hum would be the game occasionally resetting as well. Replacing caps C8 and C10 on the power board may fix this issue.

A special case of interference is present on the Jokerz game, which uses a unique stereo sound board. A deficiency in its design prevents all of the noise from being eliminated from the board. Details are available on the original service bulletin here: Jokerz service bulletin at IPDB.org

5 Repair Logs and Game Specific Problems and Fixes

Did you do a repair? Log it here as a possible solution for others.

5.1 System 9

Comet Pinball Repair Log

• Battery corrosion -- but no leaks.
• Display Power Supply voltage problem.
• All displays are dead.
• All ramps are damaged to some degree. The middle ramp is warped.

5.2 System 11

Space Station Pinball Repair Log

• Display Power Supply voltage problem (+/- 100v = 120v/-130v).
• Player 3 Display is out.
• Left Dock Kicker (does not kick).
• Shooter Lane: 2 balls at same time.
• Top Pop Bumper (does not bump).
• Flipper Rebuild:
  • Right Flipper is sloppy.
• Right Dock: ball cannot escape.
• Stuck switches (x 5).
• Rubbers need replacing.
• Shooter power barely/not always enough to get ball to top of playfield.
• General Illumination (G.I.): Left side is completely out.

5.3 Using a System 6/7 Speech Board in a Comet

A Modified System 6/7 Speech Board Functioning with a System 9 CPU

Should the need arise, a System 6/7 speech board can be modified to use 2732 EPROMs for a Comet.