Ms. Pacman sound problem - video linked

TDJ

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Hi. Looking for some advice on how to fix this sound problem:

http://www.youtube.com/watch?v=MVmSU93BegM

I am a pinball guy, but have a 4-1 Ms Pacman as you can see in video. Worked great for 2 years, but yesterday something seems to have failed. There is a hum when machine is turned on, and only sound is a click when dots are eaten. Would appreciate any ideas on the cause / what board components should be replaced. Thanks very much.

Chris
 
Well, I didn't hear a hum on the video, but I figure you have four possibilities:

1) The caps in the sound section need to be replaced.
2) The sound amplifier (under the big heat sink in the sound section) needs to be replaced.
3) Something is wrong with the 4-in-1 kit.
4) Something is wrong in the sound generation circuit leading up to the amp.

Does it do this for all 4 games, or only that one? Caps are easy to replace, and you could make an audio probe pretty easily to check to see if the sound going IN to the amplifier is good, when we know that the sound coming OUT isn't....
 
Hey thanks for getting back. It does this for all 4 games unfortunately.
 
Then start with the caps. They're cheap and easy. The sound amp can be a bitch to replace...
 
Cool. Thanks man. Will post back if its still messed up after replacing the caps. BTW, should I be replacing each capacitor, or is there one specific to the sound section? Thanks again for your help.
 
Clean and check the fuse holders first. That is something you can easily do before recapping the board.

Just make sure it's unplugged first. ;) hehehehe
 
mine did the SAME EXACT thing.. now im not saying this will fix yours. but i went by the lownmowermans guide, and replaced:

Clicky Sound

Replace 74LS174 @ 1L




checkout the whole thing, definately worth the read...

http://lawnmowerman.rotheblog.com/

and thank you jeff rothe for hosting this and not letting it die.


i should add that i di dhave a NASTY hum after a couple months and i did have to recap the board. but as far as this clicky clicky only sound, mine did the same thing and it was that one chip. I robbed one from a donor board and fixed it right up.
 
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Thanks dude. Really appreciate it. I ordered a bunch of ic's last night so that one will hopefully be the solution.
 
OOPS. I missed the sound issue and was just focusing on the hum...
 
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