Hi Studley
I am relatively new to pinball problem solving and not familiar to your machine or the Bally's of this era. Last year I got a Creature (1992 Bally) and the flasher lamps never worked. The problem was thought to be with the mpu but ended up being the ball popper coil that snagged on the ball plunger when the playfield was removed. The wire was still connected to the coil but the connection a bit dodgy and the wire mounting bracket of the coil broken giving the wire a little slack and very close to the coil bracket in which I think it was shorting with. It took a little while to find and then replaced the coil and solved the lighting issue.
You never know it could be a left field issue or my suggestion is left field and I should not confuse the issue.
Good luck and I will watch to learn.
