In my ‘59 Williams Pinch Hitter, there is a push button in the bottom of the cabinet that allows you to manually reset the high score back to 20 runs. I am not sure if this is what you are referring to or not.

The high score feature keeps track of the “all-time” highest score. It does not reset after each game.

If memory serves, I believe the high score reset switch was located inside the head of my 1956 4 Bagger when I had it.

You have to score past 20 to advance the high score reel. Is that not happening?

It seems like I had the same problem where it wouldn't advance past the standard high score. If I remember right I had something set up incorrectly with that stepper. Gear set 180º off or something. Anyway it's been so long and I don't have the game any longer. Sorry I can't be of more help.

Does the high score advance if you manually close the Hi Score Imp relay? If so you know the problem is getting the signal to that relay, and not in getting the signal from that relay to the High Score reels.

If the High Score Reel advances when you close the relay, it might be the Run Unit EOS switch (orange-black to white-blue wires) at the top of your schematic photo. If not we'd need to see the rest of the circuit for the High Score Imp relay.

/Mark