I'm having some difficulty troubleshooting some issues with player 3 on my Williams Big Chief. I'd appreciate any help anyone can offer.

-When either adding coins or hitting the start button, it skips over from player 2 directly to player 4.
-If I start the game, player 1 scores normally and once the out hole is triggered, the score motor runs but won't advance to the next player . The ball is ejected into the shooter lane still on player 1 ball 1. Players 2 and 4 behave the same.

-If I manually advance players at the player unit SU, player 3 locks the coil on the match unit that rings the bell for scoring 10 points after a 10 point target is hit.

If I play on a 1 player game, the game scores normally, the ball advances through balls 1-5 and to game over without issue.

All the issues seem to be related to player 3 in some way.

Problem solved!

I cleaned the crap out of the score motor switches and the relay bank switches and solved most of my problems. Player 3 was no longer skipped when adding players. Players and balls now progress normally through games. I ended up using a Dremel with a wool buffing wheel to clean all the contacts and it worked fantastic for getting all the contacts shiny and bright again. (I got the idea from https://homepinballrepair.com/em-score-motor-adjusting-repair-pinball/)

The only issue I still had is the 3rd player locking the coil on the match unit. As I rooted around the schematics, I decided to try to clean the player unit, even though I cleaned it before taking apart the machine, just incase some dust or something got on there. That is when I found a broken solder joint. Two seconds of solder work and all is fixed!

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