.... green screen on reboot usually means dodgy chip ram. but its only the diags, and it could have corrupted the chip registers in the crash. had the same sort of problems with my old A4000 desktop and heat/power problems. now there are no bits of wire snippings sorting the -5V line to one of the data lines? not good.
chip rams not running v.hot?
all the solder points on the joystick port are ok?
but i'd suggest what one of the other guys said, blame the joystick first!
other than that, dunno what really, but good luck sorting it out!
