Rochester, NY
Does the test button on the sound board do anything? The sounds during gameplay are triggered via solenoid transistors so if there was a driver board issue that would explain both.
Checked voltage at the coils?
(Topic ID: 225145)
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Phoenix
Williams, 1978
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Quoted from MaxAsh:As for the test switch, not sure, I'll check that and report back. I didn't even notice it was there, but just looked up a pic and I see it's located at the top right corner of the sound board.
It should play through a variety of sounds on repeat if you click it
Quoted from MaxAsh:Yep, just like the Gorgar you helped me fix recently
You need to get yourself an avatar!
Quoted from MaxAsh:I expected it to be where the red toggle switch is for the tone/sound change option. Definitely going to try it asap. If it ends up producing sound, I'll know that almost all my problems are relative to that Driver board.
Besides from the layout, this sound board is thankfully quite similar to the gorgar one, plus it has (iirc) metal jumpers below the sound data connector that you can ground for testing, instead of needing to track down resistors 
Quoted from MaxAsh:Thanks zacaj
Regarding the PIA/CPU comment, do you mean on the MPU, or the sound board itself? The CPU IC1 on the main board is a 6800 and socketed. The only PIA I see on that main board is one labeled PIA Display Output and it's not socketed.
Looking at the Sound Board, I see IC3 (MC6820 PIA), so I wasn't sure which you were referring to.
Should I check for voltages and such on the sound board first? I haven't worked on a completely dead sound issue before on this era Williams.
All referring to sound board. It should be able to enter the test mode completely independently of the rest of the game. Has its own rom, cpu, pia. Basically a simplified mpu, and can be troubleshot the same way.
Iirc 6820 and 6821 are compatible? I've never paid attention to the difference.
Check for activity on the data lines of the rom. Even if the pia is still bad if the cpu is good you should see data.
C27, 28 should have 5v, as well as pin 24 of IC2, among others. If not could be your 5v regulator is just dead.
Quoted from MaxAsh:zacaj Okay, I received my Cap Kit and new sockets to replace the SCANBE ones. I have two questions before I get started:
1) So the kit I ordered was for Sound Board Type 1 based on my research. It came with (6) caps. My question is related to capacitor C27... it's joined with C28 in the diagram and on my board. The cap kit doesn't include a replacement for C28. Do I re-use that? Or does the new cap I received for C27 remove the need for C28 altogether?
2) There appears to be jumper wires running on the back of the board between certain EPROM positions. I see a tag inside the cabinet that talks about EPROM jumpers being required for this game, so I'm assuming they're factory. Please correct me if I'm wrong.
I can post some pics if it's helpful. Please let me know!
Probably normal. Pic of front and back to be sure.
Quoted from MaxAsh:1) So the kit I ordered was for Sound Board Type 1 based on my research. It came with (6) caps. My question is related to capacitor C27... it's joined with C28 in the diagram and on my board. The cap kit doesn't include a replacement for C28. Do I re-use that? Or does the new cap I received for C27 remove the need for C28 altogether?
C28 is a small ceramic capacitor. C27 is a larger electrolytic capacitor. Electrolytics dry out with age and thats why they need recapping. Ceramics generally are fine and can just be ignored.
I've had those red wires on the backs of all my williams sound boards. Seemed to be a factory 'hack' because they couldn't route a trace or something.
Quoted from MaxAsh:zacaj When you say the ceramic C28 can be ignored, do you mean I don't need it anymore, or just that I can re-use it when I replace C27 and solder it similar to how it is currently done? I'm assuming re-use, but want to make certain!
ignored as in don't replace it, just leave it
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