OK, I swapped the TIA from my parts board, and got no picture at all, so that TIA is bad. So I put the TIA from my system on my parts board. It works better-I get limited paddle movement, meaning that the character (buckets in Kaboom) will instantly move from one end of the screen to the other without fluid scrolling, and the buttons still respond. Could it still be the TIA? Or do both boards have something else wrong? I'm sorry; I'm very new to fixing these.
UPDATE: I pulled all 3 chips and sprayed the contacts with contact cleaner, and it went back to buttons only working, no movement at all, on both boards. I'll get a TIA from Best and update the results.