Pacman arcade PCB repair
Pacman did not appear, and two of the ghosts did not appear. Additionally the text at the top of the screen (Hi Score) and the bottom (Credit) were corrupt. A tip on the KLOV forum suggested this was likely to be the VRAM addresser daughterboard. Nothing looked wrong with a logic probe so I decided to remove the LS157 and LS86 chips as I have a plentiful supply from a Dragonninja parts board.
As it turns out I didn’t even get to the LS86′s as one of the 157′s tested bad when removed, and replacing it solved the problem!