2 May 2018

Cal.50 - SETA 1989 (repair log)

An other greasy board covered by CRC. I first cleaned it after removing all the socketed chips and the battery (used for high scores saving).

Once the board was completely dry I tested it: game was dead, sync signal wasn't valid.
Probing the main CPU (68k) I found reset signal was held low. There's a reset button on this board so I had a look at it: I tested continuity and it turned out it was stuck depressed. I replaced it but saw no improvement. Next to it was a voltage control chip named "RE5VA45AC". It was dead too, possibly because the button has been kept depressed for a long time when it's supposed to be just an impulsion. I couldn't find a replacement part for it so I simply removed it and bridged pins 1 & 2 which was enough to repair the game:

Game fixed.

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