Work continues on the Bally Mr. & Mrs Pac Man Pinball Game

In the continued saga of bringing this 1980s game back to life, I begin to go over the electronics and figure out why the game wouldn’t boot up.  Normally you fire up these Bally machines and count the number of times the LED on the MPU board blinks, but in this case, the game didn’t even get far enough to begin to start up the MPU.  Fuse F3 kept blowing and the game wouldn’t power up at all…

An examination of the schematics showed an area on the power rectifier board where it was likely some components were damaged and needed to be replace.  Luckily, these were not very obscure items so I could pick them up easily.

Stay tuned for the next installment where I go into addressing an issue with a broken plastic rail guide that probably can’t easily be replaced, so I have to fabricate my own!

 

Fixing a dead dot matrix display board

The other day the DMD just went “poof” on one of my machines.  After doing a little research, and checking connections and things, I realized the DMD board died.  In this installment, I walk through the process of rebuilding the power supply-portion of a Bally/Williams WPC DMD board.  In part 1 I describe what I’m doing and introduce you to the tools I’m using.

 

Next up, let’s talk about using a meter to check circuit board traces as we go along..

Desoldering and replacing components.

Now the moment of truth!  One thing I want to add is pay very close attention to each item you are replacing on these boards.  Two diodes, capacitors or transistors may look alike, but have slightly different values or part #s.  The three power transistors and the diodes are not all the same.  You may have to bust out a magnifying glass to note the different in the markings on each part.  This should also be cross-referenced with the schematics and/or parts list from the game manual.