Having a strange issue with Hoops. The game was working fine but there were some digits not displaying properly on the basket count (secondary) A23 display board... 0 was a 4, there was no 8, stuff like that. I unplugged and plugged back the connectors and now the game boots up, plays the let's shoot some hoops sound backwards (as though it were posessed by demons) and makes weird static-like noises. Also, all the segments on the A23 display are now lit all the time. I can start up and play a game fine but the sound is all wrong. If I unplug the A23 board, I get a completely normal boot, including sounds and gameplay, but of course I have no basket points display, only the main display. Looking at the CPU board, I've tried resoldering the connector pins but really, I could tell they were fine by looking at them. U4, the 6522 chip has been replaced. According to my schematic, U5 (also a 6522) is related to the display circuit for the A23. Any idea how to test this chip? Anyone seen something like this? So little info on these gottliebs available on pinwiki or even here.

Just updating that this problem has been solved. It was indeed a bad U5 6522 (or 65C22) PIA chip... in case someone is ever searching with a similar issue.