I recently reluctantly acquired a 1975 Jennings electronic slot. The build plate only shows "3 line" for the model number, which I've never seen on another Jennings. The logic board differs from others that I've seen. The common Jennings 400 board has edge connectors. This doesn't. This board has ERNIE micro inline connectors that plug into a backplane. This dang thing actually works, EXCEPT, there is never a payout on any of the bells. All other suits pay out accurately and consistently. All other functions on this thing actually work. I think it's a miracle. This logic board seems really primitive, and perhaps that's to my advantage. It has had TONS of rework done on it in the past. I have confirmed the connections from the board to the backplane are good ( continuity ) and I also checked the condition of the finger contact boards at the reels. They all look great. Board does not appear to have cracked solders, the battery looks to have been eliminated by someone a long time ago. Does anyone have leads on resources like schematics? Anything? Thank you.