Atlanta, GA
I picked up a (thankfully) 100% functional Mr. and Mrs. Pac-Man pinball machine, and a troubled 1977 Bally Eight Ball.
The Eight Ball initially powered on but the MPU diagnostic LED did not illuminate at all. I checked the voltages and everything was spot-on on the test points. All the fuses also appear to be fine.
The MPU has been obviously and crudely repaired, I've attached a high-resolution photo. I believe the original brown chip sockets were replaced?
I took the MPU, gently removed the chips, and cleaned the tiny bit of corrosion I saw off and resoldered a few suspect points. When re-installing the chips, I noticed that socket U2 had a broken leg and I repaired as best as I could with a small copper wire. Chip U2 is actually sitting in a brand-new IC2 socket I just pushed down into the old socket; you can see the extra four leg sockets to the left, although they are NOT touching the board itself so shouldn't be causing a short.
After that little bit of work I was rewarded with a solid green LED (yay progress) with no blinking, and a still-non-functional game.
So, I'm left pondering a few things.
I don't know what else in the game may or may not be working; it's hard to justify dropping $200 on a new modern MPU without knowing the status of the other boards/solenoids/etc.
The problem could be chip U2; either it was damaged or I damaged it trying to fix the leg. Can replacements for those chips be sourced? A quick ebay search found a few "CPU chips" and whatnot but possibly I need to modify the MPU to support different chip types?
I don't know if the condition of the board is good enough to send off for repair. I've seen services offered from $60 to $160 for MPU refurbishing, and at $100+ I'd probably lean more towards the modern, new MPU that I could also use in the PacMan Pinball should I choose to.
Is the Mr. and Mrs. Pac-Man MPU board compatible? Could I do a simple board swap between the two to check the solenoids, LCD displays, kickbacks, targets, etc?
Thanks for your advice.
Sana'a
