Likewise I have gone and dumped the EPROM but have no way to verify it. I have access to the service documentation for the machine and the diagnostic ROM but I cannot find an image of the ROM to burn. The only thing I have not done so far is try it with a new battery installed.

Likewise if you press and hold the RESET button everything quiets down until you release it. With the CPU or the EPROM pulled nothing bangs off. Lights, bell, solenoids, relays, counters.everything that is controlled by the microcontroller loses its mind.

Omitting the one bad transistor (which I think is part of the seven segment display panel on the front), while I was told the machine 'used to work before the reels stopped latching' (and when I received it indeed the reels were spinning freely) when you power up the cabinet and logic all that happens is everything starts banging off at random. This board has been reassembled save for Q1 which was a bad MPS3646 (and if anyone knows a good modern substitute for it I would love to hear about it)and the DC supply has been gone over to check the capacitor ESR and will being up the DC GOOD light when turned on. As it stands right now the mechanical portion of the machine is cleaned and oiled.

Reset tilt on bally slot machine