Odd Centipede Sound problem?

Straker

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I had no sound on my centipede but I noticed when I press on the volume control it would give me sound and when I lifted the pressure it would go quiet again. So i replaced the sound pot with another one from my Crystal Castles machine. Now there is no sound at all.
Checked connetions and all seems good. finally I thought it would be interesting if I hooked a speaker directly to the board itself to see if I got any sound. I clipped a clip to a ground on the board and another clip to aud2 on the board and the other ends of the clips to a speaker. I got no sound out of the speaker attached to the board but the speaker in the machine started working like it should. When I disconnected either clip from the board the speaker in the machine would go silent.

Any idea what is going on here?
 
I had no sound on my centipede but I noticed when I press on the volume control it would give me sound and when I lifted the pressure it would go quiet again. So i replaced the sound pot with another one from my Crystal Castles machine. Now there is no sound at all.
Checked connetions and all seems good. finally I thought it would be interesting if I hooked a speaker directly to the board itself to see if I got any sound. I clipped a clip to a ground on the board and another clip to aud2 on the board and the other ends of the clips to a speaker. I got no sound out of the speaker attached to the board but the speaker in the machine started working like it should. When I disconnected either clip from the board the speaker in the machine would go silent.

Any idea what is going on here?
Dead LM324. VERY common failure on Centi.

By the way, the LM324 isn't supposed to drive a speaker directly, not powerful enough therefor the AR-2 does the end- amplification.

I had the same problem on my board and recently fixed another Centi board with also a bad LM324.

When I was "fingering" around the LM324 I suddenly started to hear sounds (although distorted).
 
I may have something similar of a problem but the sound on my centipede seems to have only 2 settings off and 11!!. The sound is so loud. Does the sound pot need replacing? Any ideas? I think it may just need a good cleaning maybe.
 
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I got no sound out of the speaker attached to the board but the speaker in the machine started working like it should

I'm curious what you mean by this. Do you hear a buzzing noise instead? Can you turn the POT and hear the buzzing noise get louder/softer? If so, then yeah probably a dead LM324. Easy enough to replace.
 
I'm looking to replace the Sound Pot. What is a good replacement for part #19-9032 or where can I find it? Radio Shack?

Thanks
 
Also, If you haven't done so yet...check your voltages. 12VDC and -5VDC feed off the A/R II board and go straight to the LM324.

Edward
 
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