Okay, I have an odd one with possibly an easy fix? I dunno. My 1985 Bally Cybernaut plays perfectly fine and no adjustments recently made to it when it started having a new issue where the left flippers will just stop working after a while of use, then after about 10-15 seconds of cool down (me pressing the button and getting no response and getting annoyed) and then, like magic it will work again for about 5-6 flips and then stops again, again acting as though something outside of the flipper itself is overheating... any ideas where I might look first? cold solder somewhere? Any ideas would be greatly appreciated.

awesome... that sounds like it makes sense... I'll give it a try!! Also it's more likely not a hairline break in the coil because the left flipper also activates an upper left flipper and they both work fine together/go dead together. Thanks again!!!

Ah! Okay, that makes sense as well. Just looking over the driver board... it is original, so I think I'll start there by reflowing solder on those connectors

That was exactly the issue! After warming up and removing the old brown bubbling solder and getting freshly flowed solder in both J2 and J3, the game works great again!!!! Thanks so much slochar and briancox!!!!