Quoted from JKaiser123:
Just quickly wanted to conduct your test of unplugging 10J3. Unplugged and turned the game on. No sounds or speech at all now. So what you are suggesting based on this is that the issue is not with the sound card? Like I said I have speech and other in game sounds. Just no background sound in play and then there is that repeating tone in attract mode.
OK good.. the wires on 10J3 are used to instruct the sound card to play a sound. With no signals getting to the card it does like it should and not play ANY sounds. The fact that when connected you have sound playing, albeit the WRONG sounds at the wrong time means the signals to the card are jumbled.
Each of those wires represent a binary digit (ground or no ground). To get the sound card to play a sound, the MPU board grounds a specific combination of those wires momentarily and then un-grounds them.
If you download the pincoder ROMS and look at the instructions for the sound test you'll have a better picture of how it works. Basically, I think one or more of those wires to the sound card are either stuck on ground, or are not grounding at all. This is what produces the incorrect sounds.
So, you just need to test each of those wires to see if they operate correctly. The pincoder sound ROM will help you troubleshoot that.
If you dont have a chip and programmer, you can start by testing each of those wires to see if they're stuck on ground. Turn the game on and go into audit mode (so you know that no sounds are supposed to be playing) and then check for ground on each of the wires. None of them should be grounded. That will at least give you half of the picture.
To reliably test the other half (whether they go to ground when they're supposed to) you will need to run the pincoder sound ROM. It is possible that you could also do this running the built-in solenoid diagnostic (you can on system 3-6a). I'm just not sure the solenoid test on a system 7 can activate sounds or not.. (I no longer have my black knight).