Moon Patrol graphics issue repair.
The game was giving me graphics issues and depending how the edge connector was touched it would change. Re-seating the edge connector did not do anything, it may have even made it worse. Looking at the PCB, someone had soldered the edge connector. The solder was really thick so I thought maybe it was not making good contact with the harness all the way across. I removed the thick solder and brought it back down to a pretty normal level. Upon testing, I still had the issue. Testing the PCB in another cabinet, it worked fine. So now I was back to thinking the harness edge connector. Moving the wires of the connector 1 at a time produced little result with changes in graphics. Grabbing the whole bundle made more of a difference. I noticed the bundle led to the power supply PCB on the bottom of the cabinet. Moving or pushing on the connector there had a consistent result in the graphics coming in and out. I removed the board and found previous bad soldering of the headers and cold solder joints. After desoldering and resoldering the headers I retested the game and it now works again. Attached are images of the board edge connector after I had removed half of the solder, the headers of the power supply pcb and what the graphics were looking like before the repair.