The mention of "click click" when the game resets has me thinking "game over relay", but Chris is correct. First thing to do is get rid of the battery on the CPU board.
I have the last (2011) version of Clay Harrell's System 80 bulletproofing guide that I have cleaned up and converted to Word and PDF. If you would like a copy, send me a PM. It should be good reading for you and answer a lot of questions.
Greg