ms. pacman help

Joshuart311

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Hello all! Noob here needing a little help. I've spent some time now searching the forum and other sites for this problem. Any help would be greatly appreciated.
 

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did you try reseating the roms? did you disconnect the board and then try connecting back?
-Mike
 
Do you have the smaler daughter board connected by a ribbon cable to the larger board?

Might take a pic of your boards to show us.

Also, have you seen this site for trouble shooting?

http://www.arcadegameover.com/pactrouble.html

When you put it in test mode, using the switch on the inside of the coin door, what happens?
 
I do have the daughterboard connected. I will post a pic soon. I have seen that site and cant relate my screen to any of the trouble screens on the site. Also, lol my machine is missing its coin door. so i have no way to test unless i can jump out two wires in the harness where the coin door should be and send it into test mode?
 
Ok, humm... So it was fine up until now then?

Not sure what else to recommend myself. Riptor on this site fixes them and he's done work for me on mine. If all else fails, send the boards to him.

He may even reply to your posts here soon...
 
I apologize for not giving any background on this. I bought this ms pac cab years ago for $5 at an auction. Got it home and played with it and got it to do this. I never had the time to try and fix it. Then about a year ago I posted that I was looking for ms. pacman parts on a local site. recieved and email from a guy who gave me two ms. pacman cocktail machines. one working and one in terrible shape with two boards laying in it. I have tried the working board i have and it works great in the stand up cab. So anyways i have three dead boards and id like to atleast get one going for the stand up pac. Im also thinking about restoring the other ms pac cocktail table but that will be a whole other thread lol. thanks for the quick responses and im confident i will be able to get this pac playable.
 
One more, what's the board edge connector look like? Condition I mean, is it hacked up or original looking?
 
The first thing when troubleshooting a Ms Pac is to take the CPU off the daughter board and plug it into the socket on the main board where the ribbon cable plugged in.

This will isolate the problem a bit. If the board works fine like this, it'll look like a Pac Man that is walking on its lips because of the Ms Pac character ROMs and you'll need to check the ribbon cable, sockets, and ROMs on the daughter board.

Next, check the 2 modules (VRAM Addresser and Z80 Sync Bus Controller) for bent pins.

RJ
 
Thanks RJ. I removed the z80 from the daughter board and replaced it where the ribbon cable was. No change. Checked sync bus and VRAM addresser pins. All look good. Any other suggestions?
 
If the ROMs on the board are the black epoxy mask ROMs and not EPROMs then you'll need to remove them and clean the tarnish & corrosion off the pins and reinsert them.
 
No change. I'm wondering if my sync bus controller or VRAM addresser is bad. I do not want to pull either loose from my working board because I fear when I put it back together my working board will be dead. I've read to many posts on people messing with a working board. I think my best bet would be to get those and try them. In the meantime I'm starting to read the schematic and ohm between the traces on the board to see if I have a broken trace. I will update as I go. Any other suggestions would be great. Thanks guys.
 
Now you're getting down into the territory of bad chips or sockets. It's more advanced troubleshooting from here on out.
 
So I went through everything once again. I plugged the board in and turned it on and got these 2 screens and now its moving garbage. It will also go to a screen with all F's. I looked at the trouble screens and im thinking I may have a problem with the 4th row chips. Is there some place I can order these chips from or do I have to burn them myself?
 

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Ok so new question. I have been trying to check my roms in winromident. I read my EPROM and save the code to a file. Then I drag it into winromident and it says not found. It's doing this on known good EPROMs. Am I doing something wrong. Was I supposed to dl a db of Roms to test against? I'm clueless on why all my EPROMs are not found.
 
I can email you the rom images if you want to compare your roms against them. PM me your email address.

Thanks riptor! Got the files and also dl some new db files for romident and it worked. So now I'm going to check all my EPROMs and go from there. I'm sure I have more questions to come.
 
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