Tech Fix: Robotron Sound

atariscott

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I had a Robotron with random noises and fluctuations in volume while playing. It sounded like static that came and went at random. It could go for hours, or it would start as soon as I fired up the game.

I recapped the sound board, figuring that leaking caps may be creating noise. That did not work. Tested all IC's and they were fine. Finally replaced the TDA2002 sound amp, and that solved the problem.
 
Yep. The three most common problems with the sound cards:
- old caps
- bad sound ROM
- bad amp

ken

EDIT: I forgot the number one problem: abuse. I find a lot of the problems stem from the transistors getting mashed and shoting the legs together. Or the legs of the amp getting broken off because something bent the heatsink back. And last but not least, traces getting cut by being scratched.
 
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Williams sound boards are crap -- that's why I made repros ;)

But seriously... caps and bad connectors going to the volume part ad the biggest problems.

I never understood why wms didn't mod the boards to be DC only for vids instead of leaving all the AC-DC conversion/regulation circuity from pin land on the board.
 
I never understood why wms didn't mod the boards to be DC only for vids instead of leaving all the AC-DC conversion/regulation circuity from pin land on the board.

Because distributors and operators only wanted to stock one board for all their Williams games, pins vids and if they could have made it work jukeboxes too.

ken
 
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