I'm trying to help a co-worker with his Ms. Pac board. The gameplay is fine, sound is fine, but the graphics (maze, dots, text and characters) seem to be 'chopped up' or repeated in places. I've attached some pics to show the problem. It doesn't quite seem to match with any of the pics or descriptions on the various troubleshooting pages on the 'net.
I put the PCB in my known-good Pac-Man cabinet, and the problem persists, so I know it's a PCB issue rather than a monitor issue. I unplugged the ribbon cable to the daughter board and installed Z80 on the main board to make it play as regular Pac-Man, but the graphics still show the same problem. I swapped in the sync bus controller and VRAM addresser from my working Pac-Man PCB but it didn't help either.
I'm looking for some ideas for what to try next. Any suggestions would be appreciated.
I put the PCB in my known-good Pac-Man cabinet, and the problem persists, so I know it's a PCB issue rather than a monitor issue. I unplugged the ribbon cable to the daughter board and installed Z80 on the main board to make it play as regular Pac-Man, but the graphics still show the same problem. I swapped in the sync bus controller and VRAM addresser from my working Pac-Man PCB but it didn't help either.
I'm looking for some ideas for what to try next. Any suggestions would be appreciated.


