SF2:CE board, pic acting up

[Eddierang]

I have my Boardmaster Supergun connected with JP21 to my NEC monitor and when I play SF2 CE and hit strong punch the picture seems to lose sync. Not touching any buttons or using composite video plays the game fine. I did try my Tekken Tag board and my SSF2 board and it seems fine. That leads me to think that maybe it’s a voltage issue? What do you think is the cause, because this has me frustrated.

[NoAffinity]

Have you measured voltage on the board yet? Measure at the C board, one of the chips toward the center of the board (like a mask or program rom). You should be at 5.0V.

It could be something shorting to/from that input line. Follow it from the JAMMA connector to where it goes on the board, and see if you find anything suspicious.