I was changing a light bulb the other day and grounded out on accident. It blew U20 in the MPU, as well as F115 and F112, so I've fixed the fuses and swapped out the MPU for another WPC89 from a different machine. All was working fine for the rest of the day. Today, the machine has spontaneously restarted several times both in game play and sitting in attract mode... sometimes it doesn't recover until I power cycle (e.g. hangs). I tried putting in one of Kahr's daughter boards and that did not help, so I am thinking it's nothing to do with the watchdog circuit.
All connections are tight, the game plays fine otherwise. Any ideas?
Milwaukee, WI
