mecha
Well-known member
I built a supergun into a HotRod SE controller, the MAME kind. I stripped the keyboard encoder board out and replaced it with a JAMMA harness that I got from an NBA Jam cabinet. I don't know if this makes any difference, but the video connector on an NBA Jam JAMMA harness has the sync pin going to the negative Vertical sync pin instead of the composite positive. it works this way, for whatever reason, probably because they shipped with K7000s but whatever.
I also installed a JROK TV encoder and the sync cleaner (it fixes the 53Hz issue with Midway boards I think) and I made my own harness going from the JROK TV board to some extra .156 headers I had laying around where I just soldered the JROK wires to the bottom. if I want to use the TV encoder in this case, I just plug the JAMMA video connector in.
well, I'm getting a scrambled mess from the TV board, I ran continuity checks on all the wires and they seem fine, and I've used this TV encoder before and know it works.
my question is am I looking at some kind of video ground issue somewhere? could I theoretically splice out the JAMMA video to two separate headers, but make it where the ground is switchable without losing any video quality?
I also installed a JROK TV encoder and the sync cleaner (it fixes the 53Hz issue with Midway boards I think) and I made my own harness going from the JROK TV board to some extra .156 headers I had laying around where I just soldered the JROK wires to the bottom. if I want to use the TV encoder in this case, I just plug the JAMMA video connector in.
well, I'm getting a scrambled mess from the TV board, I ran continuity checks on all the wires and they seem fine, and I've used this TV encoder before and know it works.
my question is am I looking at some kind of video ground issue somewhere? could I theoretically splice out the JAMMA video to two separate headers, but make it where the ground is switchable without losing any video quality?