Game King with Scrambled Screen

[FORDSBS]

Hang in there. Maybe someone will come on here that had that problem.
I'd start by checking ALL wires to make sure they are not shorting out.

[Billythekid]

I think I'm in the market for a 3802 back plane board, complete wiring harness and the distribution board that sits about main game board.

[Yoeddy1]

Have the software chips been completely ruled out?  Since funky EPROMs can cause similar behavior, and I have had personal experience with this, I would absolutely try a different software set before tearing into wiring, etc, or selling the machine for parts.

Jason

[FORDSBS]

Billythekid, Jason's a Game King guy. he should be able to help you.

[Billythekid]

Have the software chips been completely ruled out?  Since funky EPROMs can cause similar behavior, and I have had personal experience with this, I would absolutely try a different software set before tearing into wiring, etc, or selling the machine for parts.

Jason

Yes Yoddy  they have, if you look up in the thread the whole story is there. Short answer is I have two different game boards and sets of game software neither work in this cabinet but they do in a different cabinet.

[Yoeddy1]

10-4.  I would agree then that it might be down to wiring. 

Jason

[Billythekid]

I just realized that I never closed out this topic.  I ended up replacing the primary power switch. I realized that if I kept turning the machine on and off it would eventually power up properly. This lead me to explore the main power lines before they reach the power supply. As I said before, the new replacement power supply was reading low voltage. Bad power in, equals bad power out. So I replaced the main power switch and it fired up. I suppose after all those years the contacts inside the switch were making a bad connection. This was a very tricky problem to solve since the input power problem was intermittent.