Ms Pacman PCB not working

2PacMan

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Wondering if someone could help me take a stab at this. Guy i bought it from said it was working but now when i plug it in i get a garbled screen like this. I don't see any screenshots like this on the usual sites that talk about graphics glitches. This must have been one of those ms pac boards that works without the daughter card because the guy said it worked fine before and it has the z80 chip in the spot the daughter card ribbon should go. I've reseated the boards, cleaned edge connectors and reseated roms so far with no change. Thank you in advance for any help you can provide.
 

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If you did not see it working before, it was not working when you bought it.

That said - I would burn a set of stock PAC-MAN roms and see if that works. Then go from there. If it works, get a multi kit and call it a day.
 
Thank you both for the suggestions. I swapped out the roms and the two ram chips with no change.
 
And I would also check the RAM on it as well...... Brywalkerx idea is a good one to go with too....

Could be a ram issue. Could be sync bus. But returning to stock PAC board with no mods (Ms. included) would be step 1 for sure.

Also check power - I had an issue with a PAC board looking something like that - was only seeing about 3.5v on the roms.
 
Yeah, from all the experience I have with Ms Pac, ram is the likeliest culprit for that issue.

As mentioned, turn this into a Pac-Man board and double check there....if that has the same error, then go further with the RAM and check for other warm/hot chips.

The other probable failure is a ROM chip.

The non-game ROMS may have one bad one needing replacement.

And power....keep checking voltages.....


So all ROMS, all RAM, power, and does it work as a Pac-Man game?
 
Thanks for all the advice guys. I will see what i can do with this new info. Appreciate it. Is there a place i can buy new roms and ram? I don't have a burner myself.
 
What is the part number on those roms in row 5, I don't see how that could ever have worked as those look like 2532s and don't know how you could play Mspac without adding sockets and more 2532s or upgrading to 2764s or higher. I could be wrong but I don't think so in this case
 
your CPU will be hosed if the ribbon cable is bad. I have a working machine at work that did the same thing and I had to press down on the ribbon housings on either side and it came back. so it could additionally be the sockets the ribbon plugs into. carefully remove them and make sure no pins got bent.
 
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