I have been sent a DE CPU from a Tommy, the owner had random sounds playing on his machine, changed the Sound board out to prove it wasn’t that. I’ve put my Star Wars game ROM in and put it in my Star Wars to test it. On game start it plays lots of different game music / sounds, none related to what you are doing in the game. It even sometimes fades and you can hear it very quiet and then it comes back to normal level of sound but Still playing random sounds. The Switch PIA has been replaced with a new socket previously and changing this PIA has no effect. In test no stuck switches or columns just the usual ball trough 1-3 and DE target up / Fire handle position.

Wondered whether there is any tests I can do with a logic probe or it’s time to swap out (install a socket) for the 2 PIA’s associated with the sound section.

Found the issue it was the sound PIA