WPC Sound Board A-12738 Repair

These little sound boards in WPC era Bally/Williams games can be difficult to track down issues on and there are no inexpensive reproduction replacements, so the boards themselves are quite expensive if they need to be replaced.

A client brought this board to me. It wasn’t getting the usual start-up bong or any sounds on his game. The game would stay in test mode for about 8-10 seconds, boot up, but no sound whatsoever.

After making sure the ribbon cable wasn’t the problem or the already socketed chips on the board, I did a little sleuthing and with fairly high certainty determined the U9 RAM to be the culprit. I socketed and replaced the 28-pin 6264 RAM chip, plugged the board back in my test machine and viola, working A-12738 sound board.

I’ve ran into this failed RAM issue twice now on WPC sound boards. Sometimes similar issues can happen with bad I/O buffer chips, but it seems this 6264 RAM is failing with a little higher rate as these boards get older.

Socketed and Replaced U9 RAM chip

Socketed and Replaced U9 RAM chip


About Matthew Mandarano

Matthew is a cinematographer and video specialist by day and pinball fanatic at night. Somewhere in between he also finds time to play the guitar, collect vinyl records and watch a good deal of movies and TV shows.
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