Once you've had an "adjust failure" due to dead batteries, is there something you need to do to reset the board after fixing it? CPU seems completely unresponsive, single diagnostic LED indicator just holds solid and never flashes, the test switches on the board have no effect. When I power the game on a few GI lamps turn on and there is a soft "bung" noise about 5 seconds after. All fuses checked and replaced.

I just got this Big Guns out of a basement in amish country, Indiana, it was installed new in 87, played for 4 years and when it stopped working was never touched again. Its in amazing condition, its never been servicved. When powered on it showed the first half of "adjust failure" (2nd display not working so just "adjust"), the batteries were cooked but the damage had not spread.

Got it home, took out the cpu board and removed the batteries, cleaned off the acid with vinegar and soldered on a remote battery connection, easy peasy, and am completely expecting this to start right up. Reinstalled and turned it on, It clicked a couple times, but then just stopped responding. Powering on creates a hum from the speakers and a slight "bung" noise bout 5 seconds after but nothing else and nothing on the displays.

I have no doubt that no one has ever done any repairs to this machine, I've inspected every board and connection back and front and everything looks brand new. What is the low hanging fruit that I should be working through when trying to resurrect something like this after so long in storage?

Any ideas or help would be appreciated, I'm a bit stumped.

Thanks- Bax