Tech: Ms Pacman Trouble shooting



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I have a Ms Pacman that seems to exhibit some problems shown here:

specifically these 2 problems: (images)
2 Screens, characters move quickly.

2S p12,13,14 low
3N p 9 low
2R p 12,13,14 high


Score & Credit also displayed vertically on left and right side of the

5M p5 high.

Anyway, How do I fix this sort of problem? The visual troubleshooting
only tells what causes the screen to appear that way, but not how to
fix it. I don't have a manual, is there test points on the board I can
check for voltages? It has the original power supply but I'm unsure how
to test it. Any advice would be appreciated.

wiggling the daughter board on the main PCB next to the SCSI cable
seems to make other images flash on the screen. For a second it
appeared normal, then back to the split screens.

I bought a 96-in-1 and put it in just to see what it would do, on the
off chance one of the chips i removed was the problem. The problem
persisted. Then the screen whent black except for a few red boxes. I'm
assuming that the problem didn't get worse, just presented differently.
Stupid me for messing around with it without a working board, but I was
determined to see if it would remedy my problem. I hope I didn't damage
either board. Dumb move..I know. Flame away....




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OMG, I actually fixed it! I love this hobby!

My first board repair! Now I have a fully functional MS PacMan. Just
replaced the 5M chip with a socket and new IC chip. I can't believe I
actually fixed it! I was shocked when my 96-in-1 came right up. I
already had visions of sending the board out for repair.

If I can do it, anyone can do it. Look at the stupid questions I ask
all the time. :grin:

Thanks everyone for your help!


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Congrats! We all remember our first time :)

Honestly, there is a great feeling when you track down that one chip
that's causing problems and plug that board in and it works perfectly.

Mike Doyle


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Thanks Mike!

I really love teh 96-in-1! great product!