Captain America and the Avengers by Data East, this came in for repair as it was completely dead. While probing around it briefly displayed an error message but then went back to a black screen. This gave me some hope because at least the custom cpu wasn't dead but there are a lot of custom chips.
After heating up it seemed to show a bit more life than it would from cold, cranking the 5V also helped and going high enough it would actually boot. Then as it heated up I was able to lower the voltage a bit but never lower than 5.3V which is still too high for continuous use.
I decided to let it cool down and then run it at 5v while heating small areas of the board with my hot air station (low heat) until it spring to life, to narrow down the area and eventually the chip. I got to the custom chip '75', which is used for I/O (controls) and security and it fired right up.
Usually the repair attempt would end here but thanks to a kind member of the community that had a scrap Fighter's History board I was able to try the '75' chip off their board. At least according to mame source it is 75 but the markings have been sanded off. Also looking at other Fighter's History board pictures online it's possible it could be a 104 chip instead.
