First of all thank you in advance for any posts! Just recently got our twilight zone out of storage after 8 years. Replaced the original power board with the new aftermarket one and the game was working perfectly, then during game play the machine stopped working and a hard power cycle didn't reset it. On power up there is a distinct hum from the speakers and after about 15 seconds the machine 'jitters' the lights, flippers and such will momentarily activate all at once, randomly and a few dots are displayed randomly on the display. I'm unable to get any debug info from the cpu led's as it doesn't go though the startup cycle.
Any ideas on what it might be or how to start 'debugging' it. Thanks again!
Grants Pass, Oregon.