Pac-Man credit/ coin up PCB issue

LyonsArcade

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Hi guys!
I have a Pac-Man that i'm having a strange issue with. It's had some sort of hack or repair done to it, particularly on the character roms. Two traces have been cut, then jumpered tying the two chips together. This was a dedicated ms. pac conversion (on the pcb!) though, it's official so I don't know why they would have done work to those two character roms (5E and 5F). I found another place on the board where one chip's 'corner' pin had been tied to ground through a resistor. This appears to be in the sound section of the board.

I removed the daughter board and installed the Z80 in the socket, and also put two Pac character roms on the board. So now it's a Pac, with the few jumper wires I mentioned before.

Anyways, the game plays fine in free play, and plays fine out of free play if you use the credit switch. If however you coin the game up with the coin mechs, the pcb reboots.

Anybody ever had one do that? I looked at the schematics and it seems that the three chips (the two character roms and the other one) that have been 'repaired' don't have anything to do with the credit circuit.
 
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Have you checked the codes in the 4 (ep)roms? You may have a bad rom.

Bill
 
I had a board with a similar issue the other day. 2 player start was held high, problem was a bad .1 uf cap.
Not sure what kind of hack you have going on there. Mspac without aux board shouldnt have any hacks in row 5. Do you have 6 roms in row 6?
 
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