Finished "rebuilding" the joystick. It is WAY better than it was before. Still kind of a pile of junk when compared to my Gorf joystick, but at least the game can be played now.
Took apart the buttons and gave them a bath, now they actually look like they're white. Cleaned the CPO, side art, paint, t-molding, pretty much the whole exterior with some TASKI-Profi. Took years of dirt, grime, and soda gunk off the cab. The white parts of the side art had a brown tinge to them, but after the TASKI-Profi they're white again, and it didn't pull up any of the ink!
When I turned it back on the screen was scrambled pretty much exactly like my Arkanoid used to do, and the Arkanoid had a sync problem. Didn't matter what I did on the monitor chassis, nothing got better. Went down to the bottom end and touched the video connector on the filter board, and BAM! the monitor was fine again. Thought it must have been a loose wire...
Started to track down the player 1 start button not working. As I was tracing back, I came back to the filter board and when I move one of the connectors associated with player 1 start, it would work. Messed around with it for a bit trying to get it to a point where it would work consistantly and I lost the sound. But when I moved the harnesses on top of the filter board, it would come back, until I tried getting player 1 start to work again. Decided I better take the filter board out. Flipped it over and found quite a few cracked solder joints on the pin headers. Most likely the cause of all my problems. I'll be reflowing all the joints soon.
The wife flipped out when I brought this one home. Trying to get this machine up to snuff to resell it to get her off my back. Interesting game to play, but if I have to choose between this and Gorf, I'll be keeping my Gorf.