Williams System 9 - 11

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1 Introduction

Williams System 9 Board Set

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).

File:System 11 Backbox Boards.JPG

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

3.1 CPU Driver Boards

System 9 CPU

System 11 CPU

System 11A CPU

System 11B CPU

System 11C CPU

3.2 Sound Boards

System 9 Speech Board (from Comet)

The speech board used in System 9 games is essentially the same as the speech board used in System 6/7 games. However, there is one slight difference. Four jumpers were added to the board so either 2532 or 2732 PROMs could be used. Both Space Shuttle and Sorcerer use 2532 PROMs from the factory, while Comet used 2732 PROMs. Either 2532s or 2732s can be used for any of the games.

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

Power/Regulator Board

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 fuse values used for the flash lamp power circuits.

3.6 Other Boards

3.6.1 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.

3.7 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

4.2.2 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 coming out 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.

4.2.3 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.

4.2.4 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) and you might have to desolder the chips to remove the corrosion and repair traces.

4.2.6 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

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4.4.1 A/C solenoid/flasher problems

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4.4.2 Special solenoid problems

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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.

4.8 Sound problems

4.8.1 System 9

4.8.1.1 Jumper Settings for System 9 Speech Board

Jumpers Circled on a System 9 Speech Board

As mentioned above, the System 9 speech board is essentially the same as the System 6/7 speech board with one exception. The System 9 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 Using a System 6/7 Speech Board in a System 9

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.

4.8.1.3 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.

4.8.1.4 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

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.