Hey guys, I'm hoping someone could help me with a sound issue - namely there is no sound.

Based on feedback, I completely assumed that continuity / the cabinet speaker was the issue. I tested with 2 known working speakers and it did not restore the sound. Does the "sub" need to be specific Ohms or whatever to still produce any sound from the machine? I tested continuity at various points along the speaker wire chain and even from one connector on the sound board to the other connector on the sound board. It tested positive continuity all around.

I can't see how it's a bad chip since I have tried 2 entirely different sound boards.

In total, I have swapped the sound board, cpu board, and ribbon cable between them - and confirmed continuity along the speaker/sub wiring. I even swapped in a spare speaker panel assembly, just because. Nothing.

I'm at a complete loss.

Anyone have any other thoughts?

Thanks guys!

Based on these comments, I connected some old headphones to the 2 pins and did not get any sound. As I mentioned in my original question post, among the things I tried was swapping the sound board, cpu board, and associated ribbon cable from another game. None of this made a difference, which is why I was thinking it was in the wiring somewhere.

I assume that any set of old 2-wire headphones would work here?

Assuming that's the case, any suggestions on where to look next?

I'm connecting the wires from an old pair of headphones to the pins with the black and black/yellow wire connect (504 & 505?). No sound. I swapped sound boards, still no sound. I'm either doing something dumb (completely possible) or there is some issue upstream. Any thoughts of where to go from here?

OK, I'm going to be a dolt here...where do I check voltage on the sound board? Across the two pins we're discussing that lead to the speakers? Should it be 5v?

So, I get 5V coming from the CPU board. I do not appear to be getting 5V or 12V at the other connector coming from the transformer. This would explain why swapping sounds boards, cpu boards and ground straps didn't change anything.

However, I guess I don't know how to test voltage from the transformer? I'm not reading power on the green/gray wire coming from the transformer, but I tried testing the same thing in another of the same machine (that works), and I didn't get any power reading there either.

Is there something special about catching these readings? Multimeter on DC, one lead on the gray/green pin at the 15-pin molex, the other to ground strap. Same way I tested voltage from the CPU board. What am I missing?

OK, I'm an idiot. I was measuring for DC, but it should have been AC from the transformer. At connector 501 I am getting 20VAC, and I'm getting 5VDC from the CPU. Fuses test fine, and I do not have a sound overlay board.

Sorry to be such a pain with this, but if my speaker circuit tests fine, and the sound board is getting proper power, it would seem the issue is somewhere on the sound board. But it seems unlikely I would have the same issue on 2 sound boards, one was confirmed good when it was removed a while back.

Yes. I don't hear the bong or the coindoor button noises, but then I go into one of the music tests and still get nothing.

Thanks for all this! This progression of things to check is really helpful.

In terms of swapping boards, the only game I have of *almost* this era is TZ. I know it has several additional boards, but of the sound/cpu/power driver, which of these are the same to where I could swap boards into TZ and boot it up to test them?