My original MPU finally bit the dust. It had acid damage, but worked fine for the past 5 years or so. Anyways, bought a Swemmer board to replace it, and am having a weird issue where as the game will only boot maybe 1 out of every 20 times I turn it on. If it doesn't boot, I get nothing on any displays, and just GI lights on the playfield. All voltages are fine, +5v is showing +5.06, although I did raise that to +5.10 without any effect. When the game does boot, it plays fine. I had it on this morning for over 3 hours, and played roughly 15 games or so. Turned it off, and back on, and nothing.

The pin has all ground mods done, and I have verified ground to the Swemmer board, and connectors are fine, as I repinned/replaced suspect ones years ago. Swemmer LEDs indicate all is well, including the +5v. I even tried unplugging everything from the board except the displays, and it did not help. Also, slam switch solder jumper is in place on the board, although this is not a slam switch issue (no rolling zeros).

I've been talking to Keith @ K's Arcade, and so far, we haven't pinned anything down. I supposed it could be a defective board, but I think that is highly unlikely. Having said that, I really have to clue what else to check here.