Gorf

Sounds are generated on the board the manual calls the "game board". It's the board with the two connectors on top. The audio signals exit this board and then go through a small amp board. This board is mounnted behind the coin bucket area. This board also contains the volume pot. I find this board more prone to issues than the "game board".

Edward
 
If you have no sound at all its probably one or both of the transistors on the amp board. TIP31C if I remember correctly. There are also a couple resistors on the board that are usually burnt. Replace them with a 1w instead of 1/4w. Even when burnt they are usually still intolerance but I have had a few that were off spec and even completely open.
Before doing anything verify you have power to the amp board. If one transistor went out it can take out a fuse in the bottom of the cab. If you find the fuse is bad its a good bet you have a shorted transistor. I usually just replace the pair while I have it out.
 
Thanks for all the advice and the pic. I replaced the smallest socketed chip on the board that Boardjunki showed the picture of and the sound was back to normal.

Thanks everyone
 
Thats the speech chip, should only cause the speech not to work. You didnt say if it was just a speech problem or all sounds.
 
Thier was no sound at all. Replaced that chip with an extra that I had and all of the sounds came back. What do you think could have caused this? Im interested to make sure thier no other problems.

Thanks
 
That's very strange.. like riptor said, that chip only controls the speech. Somebody more knowledgeable than me will have to let us know if it's possible... that the chip was shorted or something, and therefore pulling down the audio out or whatever, but I dont' think that's possible because as I remember it, the three signals for the sound get sent to the amplifier on three seperate lines, that's why you can adjust them seperately. Even if the speech chip was all screwed up, it shouldn't be able to affect the other two lines.

Probably a coincidence, which is good because it means that 30 dollar chip you just replaced probably wasn't bad. It may have just been when you reseated the chip you reseated the entire board, which fixed the sound.
 
Probably a coincidence, which is good because it means that 30 dollar chip you just replaced probably wasn't bad. It may have just been when you reseated the chip you reseated the entire board, which fixed the sound.

I'm going with LyonsArcade. Replacing the chip probably wasn't the fix......removing the entire card (to get to the chip) and re-installing it was probably the fix.

Edward
 
I'm going with LyonsArcade. Replacing the chip probably wasn't the fix......removing the entire card (to get to the chip) and re-installing it was probably the fix.

Edward

+1

You might try the other chip again. It really sounds like a bad connection and not that chip.
 
Yep, either reseatting the card or one of the two customs were dropping a connection in their sockets. Im not sure if the customs handle sound or not, think they are I/O but probably sound too kinda like a pokey chip. Either way I would retest the old SC-01 chip. They are really hard to find so you dont want to possibly toss a good one.
 
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