Tech: Ms Pacman Trouble shooting

Archived from groups: rec.games.video.arcade.collecting (More info?)

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

http://www.arcadegameover.com/trou [...] uble1.html

specifically these 2 problems: (images)

http://www.arcadegameover.com/trou [...] age100.jpg
2 Screens, characters move quickly.

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


and


http://www.arcadegameover.com/trou [...] age102.jpg

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

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....

TIA

-CF

Archived from groups: rec.games.video.arcade.collecting (More info?)

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