I have never seen this issue. The information for the credit display shows in the player 1 and credit display. The problem persists with the original MPU and an Altek. I've also changed the driver from original to altek; problem still there. I've even moved displays around. Nothing that I know of has changed in the wiring harness. I really don't know how to even approach this diagnosis. Any ideas or anyone ever seen this. I thought I had seen everything with a early Bally, evidently not.

KISS (resized).JPG

Bump! Is this really a unique problem.

I've owned this game for three years. I'm going to repin the connector J1 today. Since the problem is there with multiple MPUs it has to be in the connector. It had pinscore led displays and they went completely crazy, I replaced them with original displays and got the result in the picture. It's a Bally so I'll start with the connectors. Knowing how the display signals leave the MPU its hard to understand how this is even possible.

^^^^^ Genius! This is one for the repair manuals. Unplugged the coin door and everything was normal. Plugged it back in, same problem. Inspected the start button only to find the stack was loose; the insulator had moved to the side and the switch was shorted. straightened the stack and tightened it up and it's back to normal. There are still tricks to the trade to be learned.