Sound Board Repair
 Williams Sound & Speech Boards 
Firepower and others.

System 6-9 Sound / Speech Boards

Sounds and speech are one of the most important parts of a pinball game for me.  Few things are more depressing for me than the sound of a pinball rolling around the wood with no background noises and without sounds of points being scored.
This tech note deals mainly with the square sound board Type 2 (with or without the speech "daughter card"). Williams part number is 1C-2001-146-x, although much of the same information applies to the Type 1 boards.

If you have a Type 1 board to fix, head over to the WarpZoneArcade for an excellent article by Lindsey Rupertus.

I asked a question on his arcade blog site about running the Type 1 Proms / Eproms in a Type 2 board. Which in my opinion are more reliable and sound better (less fuzzy and less hum). He has come up with a solution. If you have a Type 2 square board need to to "make a rectangle out of a square" board to run your original Sound ROM chip (or a copy of ROM 1 on an Eprom)... look here.

Looks like there is a Hardware OR a Software solution to this problem

Hardware Solution with the Original WMS ROM The hardware changes on the link above from WarpZoneArcade mean you can still run an existing sound ROM / Eprom, but it does involve a hardware hack to the square board. If you have a socketed PIA and can solder, then there is a way to bend out legs and you won't have to cut board traces. Again, get in touch with me on email and I can help documnet this for you, if you feel you need to go down that route. After all, not everyone like running modified ROMs or has access to a ROM burner to program a 2716 Eprom.

Software Solution with a new ROM There may be a simple software solution is to use in a working Type 2 board, use a modified "Sound ROM 1".

This ROM can run Sound ROM 1 on a Type 2 (square board), with no hardware modifications. You would need to be able to burn a 2716 Eprom and be willing to try it out. Set up the board for a 2716 Eprom in IC12 and no speech: Jumpers W1,W2,W5,W7,W9,W10,W15 connected (only). DS1 (DIP switches both OFF). Install "SOUND1RA ROM" and that's it.

Some other useful Sound Board Links:

Leon's excellent site has a good starting guide for Williams Sound board repair.  A test chip you can download and burn to a Sound EPROM which will "pulse" the PIA and also test memory.  Harder to do advanced fault repair without this.

A clear diagram of jumper settings for most games on Williams Type 2 boards can be found at !

See this link for a quick and dirty sound board switch and connector diagram. It also shows the solenoid sound select numbers on the Inputs at 10J3 for a system6 (or system7) game. Here is a diagram on placement of the Speech ICs, which isn't very logical.

Note: This diagram works for any of this type of Speech Daughter board. Replace your game number nnn in ST-nnn-ROM# format. See examples for Firepower (497), Alien Poker (501) and Black Knight (500), which are my favourites. Although I provide this information for clarity, I still recommend you replace Original Speech Mask Roms with newer 2532 Eproms.


Speech ROM IC socket locations

Before you start to repair your Williams sound card... are you sure you have a sound board problem?

Do the sounds work correctly from the sound board "self test"?  Have you followed the diagnostic procedures in the game manual and checked the "Solid State Flipper Maintenance Manual" or equivalent for your game? For Firepower and later, download the PDF of FlipperManual

OK.  It works on the sound board self test, but you still get missing or incorrect game sounds... what now?

On all models of sound card you can ground the input pins and that should gives an indication that the sound board is working.   For Type 2 boards (square ones) that's 10J3 pins #2-4 and 7  I believe it's the same on the Type 1 boards (Flash, etc). 

By System 7, Williams had stopped using solenoids to fire sounds and had added a dedicated Sound/Comma PIA on the CPU board to talk to the sound board.  Yes! More playfield coils and flashlamps were now possible.

So, on a Black Knight and later System 7 games, the fault might be on the CPU board. Perhaps PIA 5 - IC36 (a 6821 PIA) is a suspect as this drives the sound board.  The outputs of the IC36 PIA at PA0-PA6 connect to 1J8 starting at pin 12 (1J8 P12) and run backwards numbered as the Sound Selects in the table below.

In theory Williams provided Sound Selects 0-6,and could have programmed 127 sound & speech calls.  But the sound boards at the time never used that many, to my knowledge. So you only need to worry about those shown below unless you add your own sounds and programming!

Also do first check the output pins at 1J8 on the CPU Board for cold solder joints, before replacing a PIA.

SYS 7  1J8  Sound & Comma Outputs
Pin Function Wire Colour
1J8 P1 Comma 3 & 4 Brown/White
1J8 P2 Comma 1 & 2 Violet
1J8 P3 Key (*) N/C
1J8 P4-7 No Connection White
1J8 P8 Sound Select 4 Yellow
1J8 P9 Sound Select 3 Green
1J8 P10 Sound Select 2 Blue
1J8 P11 Sound Select 1 Red
1J8 P12 Sound Select 0 Red / Yellow

On System 6 (and earlier), you may have a fault on the DRIVER BOARD and specifically one of the solenoids in the range #9-13.    So the Solenoid diagnostic test will help you figure it out for System 6 (and perhaps for System 7 too). Although remember the calls are made differently.  

Getting Started.  If diagnostics don't work as you expect, you can ground the metal tabs of the TIP120 or TIP102 transistors (briefly - they may be real coils or flash lamps!) on the bottom 2 rows of the driver board.  This is what the logic does, and you should hear 5 different sounds.  The first 3 are at the bottom left of driver board, and then the first two the next row up are the sounds #9-13 as shown on the chart below.

Driver Board Positions
2J9 10 9 6 7 8
2J9 11 12 13 14 15

* Blue shows 5 Sound Transistors on System 6 / 6a

The "grounding test" is a quick check for continuity from TIP120 transistor centre tab out to the sound board.  You can of course also turn off the game and measure it with the Ohm meter between the centre tab and the input pins on the sound card.  If you get high readings, check for cold solder joints on the input pins of the sound board at 10J3.  Also then check the output pins on the Driver board at 2J9.  Reflow the solder on these pins.  Replace the connectors.  It's always the IDC connectors that go wrong on these games!

Another tip is that you should see the centre tab of the Blue "sound transistors" running at about +5v DC on the driver board when not grounded.  Other TIP120's (or TIP102's) could be at the coil potential so have your DMM set on +50v or so for this test.

If you get this far and can get 5 distinct sounds, then the problem is not the sound board, nor the connection to the driver board (or the sys7 cpu board).  Still talking about system 6, it could be: the power transistor TIP120 (or TIP102), the 2n4401 pre-driver, the 7408 IC or finally the 6821 PIA at IC5.  Follow a driver board repair guide to get further. 

Complete list of Driverboard 2J9 pins and the associated transistors (for Sys3-6) are:
SYS 6 Driver Board 2J9 Sound Outputs
Pin Sol. Function Transistors Wire Colour
2J9 P9 # 9 Sound Select 0 Q31 / Q30 Brown / Black
2J9 P8  (*) Key   N/C
2J9 P7 #10 Sound Select 1 Q33 / Q32 Brown / Red
2J9 P6 #16 Coin Lockout* Q45 / Q44 Brown / Grey
2J9 P5 #15 Flash Lamps* Q43 / Q42 Brown / Violet
2J9 P4 #14 Credit Knock* Q41 / Q40 Brown / Blue
2J9 P3 #13 Sound Select 4 Q39 / Q38 Brown / Green
2J9 P2 #12 Sound Select 3 Q37 / Q36 Brown / Yellow
2J9 P1 #11 Sound Select 2 Q35 / Q34 Brown / Orange

List of J3 sound select pins on the System 6 or 7 sound board are:
SYS 6/7 Sound Board Inputs
10J3 Pin Sol. Function Wire Colour
J3 P3 # 9 Sound Select 0 Brown / Black
J3 P2 #10 Sound Select 1 Brown / Red
J3 P5 #11 Sound Select 2 Brown / Orange
J3 P4 #12 Sound Select 3 Brown / Yellow
J3 P7 #13 Sound Select 4 Brown / Green
J3 P1  (*) Key N/C

On System 6, using only 5 solenoids for sound limits the number sound and speech calls.  I make it 25 = 32 so only 31 usable combinations, a call of all 0's being null. But (using Firepower as an example) you then can have all the combinations of maybe 20 sounds plus the 11 speech phrases it "knows". So it's enough given the small amount of sound and speech memory they had to work with at the time. In fact it's amazing! For more background, see: An interview with Eugene Jarvis, the sound engineer and programmer for Williams at the time.

Changing the sound board won't cure the problem of a missing solenoid signal, and a major clue is that the sound board tests good, and is also good when grounding the 5 input pins at (Board #10) J3 on the sound board.  While the "in game" sounds or game diagnostics will play incorrectly or have missing sounds. For example someone wrote to me saying their Firepower game could say "Power" but not "Fire" it turned out transistor Q35 (a TIP120 or TIP102) was missing from the Driver board. That's 2J9 pin1 solenoid #11 (and fires sound select #2)according to the above sys 6 table. Without that sound select being triggered, I figure only half the game sounds would be produced (24-1> = 15)!

If a transistor gets shorted on (or a 7408) and one of the sound selects is constantly grounded the from the Driver Board, you will certanly get fewer (and usually the wrong) sounds played. You can chase this kind of problem around for hours, if you don't work logically through the problem!  See Problem #6 at  Pinball Restorations for a decent approach. It's about a sound fault on an Alien Poker, but it had exactly the same driver board and sound/speech boards as Firepower (and other Williams games from that era).  BTW - Alien Poker was the last System 6(a) game, but had 7 digit scoring displays! Algar was also a Sys 6a with 7 digit displays.

Advanced Repair.   OK, so you actually have a sound board fault.  You need to get it on the workbench to test any further.  You don't need to use an AC supply!  A PC AT power supply has the +12v and -12v DC you need on the mother board connectors, my experience is that the older the PC the better.  Search for "AT Power supply" on the web for the connector locations or measure for them with the DMM.  The wires on mine were coloured Yellow and Blue.  Ground was black as usual.  I slid them out of the motherboard connector and they fit right in a .156" socket to connect to the sound card.  Took 5 minutes.  Also see Leon's excellent site.  You will probably need his sound test ROM.

The very first thing is to make sure you have the correct jumper settings and ROM types.  You can NOT "mix and match" sound and speech ROMs as you like.  From my experience, which is on Williams System 6/7 pinball the Sound ROMs are 2716 Eproms and the Speech are always 2532 Eproms.  The exceptions are video games (and a few pinballs), such as Defender,Sinistar, Robotron and Joust which use a 2532 on the sound board ROM and each has special jumper settings.

Also you need the correct Sound ROM type for your game's Speech ROMs.  Firepower AND Alien Poker both use "WMS Sound ROM 3" no matter WHAT the Alien Poker manuals (or ROM downloads) say!  This is the only way I ever got speech to work on Alien Poker.   If you have Blackout, you will need a 2716 Sound ROM 2 to go with the Blackout 2532 Speech ROMs

This is mainly a warning if you will be plugging together different boards on a workbench, don't trust that all Sound ROMS will work with all speech boards.

Link here to my mad experiment to fit 4 x 2532 speech ROMs on a 27128 Eprom and get it working for a game.

Also distrust both the switch settings AND that you could have a faulty switch on the Type 2 board. I have seen this! Test by removing the 2-way switch, or jumpering across the back of the switch.

If DS1-2 is not connecting, you will hear sounds-but NO speech.
The clue here is that if you press the sound board diagnostic switch, you hear BOTH sounds and speech - that's what mine does.

Other problems that could cause sounds but missing speech include:
W1 is jumpered,
W9 is NOT jumpered (W4 is probably in place),
IC7 (inverter) faulty,
IC10 (6821 PIA) is faulty (use Leon's test chip -see below)
Faulty speech board (no speech),
Gaps in speech usually point to a faulty Speech ROM, look in the manuals for which ROMs hold the missing words.

Switch 2 MUST be ON for speech.  OFF for no speech.
Switch 1 selects Tones or Synth Sounds.  ON for musical tones (more like bings and bongs), OFF for Synthesized Sounds.


     DS1:  Set correctly for Sounds and Speech.



     DS1: Set for Sounds only.  You will also have to jumper W1 if this is not in place.


Using the Sound Board Test Chip. Leon's test chip and instructions will be very useful.  Search on his page (linked above) for "Repair method sound boards"  Note: The the test chip will not start on a Type 2 board with jumper W1 missing, unless the speech card is also connected.  Mine didn't start "pulsing" without the speech card.  You also need to put the Test code on a 2716 eprom.

Here's the best solution:
Jumper W1, and set DS1: SW1 and SW2 to OFF and run without a speech board until the sound is working 100%.

This may not be obvious at first, but you must get back to a basic setup and work forward from there.

The following is my attempt to list notable Williams games that used these boards. I'm interested in System 6/7 pinball games, and even so some are left out. If your favourite game isn't here, I'm sorry! Life is tough.
I have conflicting lists, Hyperball could be a 2532 ROM #8.  the file hypsnd12.532 has a checksum of 0x25A8 - which doesn't match other sound ROM images I have seen. So the list is not perfect, I have made some corrections as of Feb 2011 after more research. If you have updates or can confirm Williams sound ROM numbers (and even betgter provide checksums or the source files) please email me.  I'm fairly happy the games with speech in the first table are right, less so with the Video games and Hyperball.  e m a i l :  richard (a_) firepowerpinball (do_) com. _ = missing t's.

Williams Pinball Games needing Type 2 Sound Board and a Speech Board:

Blackout 6 495 Sound ROM 2 
Gorgar 6 496 Sound ROM 2
Firepower (r) 6 497 Sound ROM 3
Black Knight(r) 7 500 Sound ROM 5
Alien Poker 6a 501 Sound ROM 3 confirmed
Jungle Lord 7 503 Sound ROM 3
Pharoah 7 504 Sound ROM 6







(r) Steve Ritchie Game Design

Video Game with Sound and Speech Board:
Sinistar (cockpit front) & Upright, Type 2, VIDEO ROM 9

Pinball Games with Sound Boards Only:

Flash (r) 4 486 Type 1 Board, ROM 1*
Time Warp 6 489 Type 1 Board, ROM 1
Stellar Wars (r) 4 490 Type 1 Board, ROM 1
Laser Ball 6 493 Type 1 Board, ROM 2
Scorpion 6 494 Type 1 Board, ROM 1
Algar 6a 499 Type 1 Board, ROM 4
Cosmic Gunfight 7 502 Type 2 Board, ROM 12
Solar Fire 7 507 Type 2 Board, ROM 7
Hyperball (n) 7 509 Type 2 Board, SPECIAL ROM 8 ??
Barracora 7 510 Type 2 Board, ROM 4
Time Fantasy 7 515 Type 2 Board, ROM 13
Warlock (pin) 7 516 Type 2 Board, ROM 14
Defender (pin) 7 517 Type 2 Board, ROM 15
Joust (2 player pin) 7 519 Type 2 Board, SPECIAL Snd_IC12.532 ROM
Laser Que 7 520 Type 2 Board, ROM 3
Firepower II (m) 7 521 Type 2 Board, ROM 13
Star Light ** 7 530 Type 2 Board, ROM 4 confirmed on my game!















(r) Steve Ritchie Game Design    (m)  Mark Ritchie Game Design     (n)  Not a Pinball, more like a gun game that shoots tiny pinballs.
* Sound ROM 1 was used from World Cup #481 to Scorpion #494, but not Laser Ball from my notes.
** Quite a rare and beautiful pinball, which I own.  Only 100 were produced, the last Williams System 7. You don't see them often.
     Played a nicely restored example of this game at Pinball Expo in Wheeling, IL (near Chicago, the home of pinball).

An annoying fact is that  from around system 7 most WMS sound ROM files are all named something like SND_IC12.716

There is some useful pinball sound file checksum information here (Tom Callahan's

Bubbles Type 2 Board, VIDEO ROM 5
Defender (Video) Type 2 Board, VIDEO ROM 1
Joust (Video) Type 2 Board, "VIDEO" ROM 4
(Checksum matches ROM 4 from Algar, Barracora and Star Light)
Robotron 2048 Type 2 Board, VIDEO ROM 3
Sinistar (cockpit rear) Type 2 Board, VIDEO ROM 10






Note: VIDEO ROMS and those for Joust (a 2 player head to head pin) and Hyperball are 2532 Eproms

Why?  You might not have an 8088 CPU, and if you upgrade to a 6802 there is one less IC (the 6810 RAM) to go wrong.

You can get the Type 2 board to run on a 6802 CPU, by cutting a track called W14.  It isn't a 0 ohm resistor, it's a track under R30, the 3rd resistor in from Left on the Bottom Left of the board. W14 grounds pin 36 of the processor for a 6808 CPU. 

If you want to use a 6802, cut the track W14. 

Pin 36 will go high through the 4.7K "pull up" resistor at R30.  You can then remove the 6810 RAM as the 6802 has internal RAM.  Very careful if you remove the 6810 RAM at IC11.  My advice is to just LEAVE IT (or the socket) in place if the card functions with it there. That way it can be reverted back to 6808 operation in future.

Good instructions found  here at : Robotron-2048 again.   Useful site and Dave has a nice Defender pinball as well.

WILLIAMS SOUND BOARD  (e.g. 1C-2001-145-x any square "type 2" board)

Warning: Again if you remove the socket for the 6810 RAM at IC11 be very careful as the traces (Address/Data Lines) connect onwards to the 6808 CPU at IC9.  I got in a whole world of pain and so document the following.

Pin Mapping of IC12 (Sound ROM) to IC9 (6800 /6802 CPU) and IC11 (6810 RAM)

Sound ROM   CPU 6808/02   6810 RAM Function
IC12 P 1 -> IC9 P16 -> none (A7)
IC12 P 2 -> IC9 P15 -> IC11 P17 (A6)
IC12 P 3 -> IC9 P14 -> IC11 P18 (A5)
IC12 P 4 -> IC9 P13 -> IC11 P19 (A4)
IC12 P 5 -> IC9 P12 -> IC11 P20 (A3)
IC12 P 6 -> IC9 P11 -> IC11 P21 (A2)
IC12 P 7 -> IC9 P10 -> IC11 P22 (A1)
IC12 P 8 -> IC9 P 9 -> IC11 P23 (A0)









Sound ROM   CPU 6808/02   6810 RAM Function
IC12 P 9 -> IC9 P33 -> IC11 P 2 (D0)
IC12 P10 -> IC9 P32 -> IC11 P 3 (D1)
IC12 P11 -> IC9 P31 -> IC11 P 4 (D2)
IC12 P12 -> IC9 P1, P21 -> IC11 P 1 (GND)
IC12 P13 -> IC9 P30 -> IC11 P 5 (D3)
IC12 P14 -> IC9 P29 -> IC11 P 6 (D4)
IC12 P15 -> IC9 P28 -> IC11 P 7 (D5)

IC12 P16

-> IC9 P27 -> IC11 P 8 (D6)
IC12 P17 -> IC9 P26 -> IC11 P 9 (D7)










Sound ROM       6810 RAM Function


IC12 P18



if W2 closed,

IC7 P8







IC12 P18



if W3 closed,

IC7 P9, IC9 P20




IC11 P12



IC12 P19-> IC9 P19 -> IC11 P15 (A10)
IC12 P20 -> IC2 P9 (7442) ->   (CS1)


IC12 P21



if W10 closed,

IC11 P13 and IC3 P8






IC12 P21 ->

if W11 closed,

IC3 P6, P9 and P10






IC12 P22 -> IC9 P18 -> IC11 P14 (A9)

IC12 P23

-> IC9 P17 -> IC11 P10 (A8) ***
IC12 P24 -> IC9 P 8, P35 -> IC11 P24 (VCC) +5v













  *** This is tricky.  It is conected to IC11 via IC7 (hex inverter) P12/P13 so 

IC9 P17 and IC12 P23 (A8) -> IC7 P13, (inverts signal) then IC7 P12 -> IC11 P10 (CS0) 

The Sound board has its own PSU  (Power Supply Unit)


[Type 2 Sound Board AC][Type 2 Sound Board AC]
Sound Board Fuses and BR Diagram (with a simplified animation of the +12v output at #1).
The other output at #4 "sees" only the negative half of the sine waves.

As you can see, it takes a dual 18.7v AC inputs from the Transformer and fuses then rectifies it.  A similar design to the Solenoid and Lamp circuits on the main PSU in the cabinet.  I have also seen Sound Boards where the BR1 was missing and replaced by 4 x diodes, which also works.  Two were mounted on the front and two on the back wired as shown, the bands on the diodes would all point in the direction of TP1 (+12v).  I would start at 1N5401, rated 100v @ 3A

Why did they have a different PSU for the Sound card?
Perhaps the isolation was to provide a "cleaner" sound, by avoiding interference from other components.
Early Williams System 6/7 and "cleaner sound" were used in the same sentence.  Ha!  I like it.

 If you have updates (or comments) please  e m a i l :  richard (a_) firepowerpinball (do_) com. _ = missing t's.