Sound/Audio Issue - 1991 Williams

Kryzsky

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Less than a week after I completed work on my T2 and was issue free, another problem appears.

Started noticing a slight electronic burning smell, very distinct if you are familiar with it. Shut off the machine and started to inspect and basically sniff around, could not pinpoint where it was coming from.

Two days later while playing the audio freezes up, stays like this until the ball drains. Later on while testing this happens again and I shut off the machine, inspect the audio board but nothing is obvious. Continue testing and this time the sound drops out completely and the electronic burning smell returns.

Gameplay and all lights are fine, the only issue is the sound.


Which components should I be focusing on and inspecting closer? Is all sound data on RAM chips, if they are toast how do I find replacements? How likely is it that my entire audio board needs replacing?


Thank you
 
I would first check the transistors with the big heatsink (bottom right, normally there's a cardboard protection over them) as these can run very hot..
Also check out the capacitors (and maybe replace them) - you can't test these with a dmm I think, just check voltages on the board.

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Last edited:
Took the board off and did a close inspection of every component. All transistors, resistors, etc seems fine.

Of the 3 plugin ICs in the top right corner, one of them seemed to not be seated properly. It's possible that pin #1 was not making proper contact. Not sure how it came loose since I have never even touched this board before. Game has been on for the past 40 mins with no issues, sound is on and not freezing, no sign of the electronic buring smell either. We'll see if that did it.
 
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