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In the process of troubleshooting a set of Capcom 1943 (US version) boards, Pin 16 (Interrupt) is being held low - which I assume will also keep the CPU from executing any instructions. While attempting to trace back the signals responsible for Pin 16 being held low, found that two legs on device 11J (demultiplexer) are shorted together (Pins 11 and 12). Thought for sure this was the culprit, but then after examination under a microscope it appears that Leg 11 was purposefully cut, bent over, and soldered to Leg 12.


By chance has anyone seen or heard of this being a factory-delivered configuration? By the way, there is nothing on the schematic to indicate that this is the as-built configuration.


Please refer to the image below (Location 11J):




Thank you.