My Surf Champ is almost completely functioning! One last issue:
Only one of the top five rollovers is supposed to be lit at a time - the light is supposed to rotate in order after the spinner is hit. (Each flip of the spinner advances the light by one rollover - at least that's the way I think it is supposed to work.) But on mine, the top left rollover remains lit all the time - never advances.
I believe this movement is controlled by the KS relay ("Advance Unit Relay"). So I turned the game on with the playfield up and spun the spinner. The KS relay coil didn't energize. And the wiper didn't move at all. I looked at both sides of the relay and they looked the same, as if the metal leading the the wire had worn off over time. I figured this was likely the reason why it wasn't working.
But then I looked at the AS relay ("00-90 Unit Relay") in the backbox. It is just as worn and dirty. But when I fired up the game and turned the spinner, the AS relay energized and that wiper did move. So now I'm thinking it's not because the metal on the KS disc is worn.
Any suggestions on what I should check now?