Slowly but surely making progress with some start-up issues on my 4 player Bally Flip Flop. However, when I reset the game the Ball Count Unit does nothing. No Ball in Play light on the backglass. I can manually push plunger in solenoid but still does not produce and Ball in play.I f I play the game and let the ball drain, it will continue to play beyond the 5 balls which should end the game. I don't see any movement of switches or relays or anything on the Ball Count Unit during the initial startup. There are other things to fix in the startup that may be causing this. The Credit Button does not start the game, nor is a credit decremented from the credit wheel. I don't know if there's any relation to the Ball Count Unit problem. If Jumping wires within the circuit is an option, which switches/wires specifically would I connect my alligator clips to? I've read the Jumper page link but am still unsure how to go about it. Any direction would be appreciated.

The Ball Index relay IS energized. The Extra Ball relay is not. Nothing I do will get any of the Ball in Play lights (1-5) to come on in the backglass. I checked the bulbs and they are okay.

Yes, Credit relay does energize, and the other relays, Coin, Reset, Score Motor, are in motion. No movement anywhere on Ball Count Unit. Ball kicks out, but no Ball in Play indicated.

I just observed when I manually advance the Ball Count Unit the Player Reset relay energizes. It does not stay energized, but it does energizes each time I advance the BCU up to the next ball. Still, no Ball in Play lights.

Wow! Cleaning and adjusting that switch on the Game Over relay did the trick, Thanks! Ball Count Unit reset at game start and shot out ball 1 into shooter lane. I played thru 5 balls and all digits, 1,2,3,4,5 lit up on the backglass. Much progress! However, after ball 5 drained the game did not end, rather, another ball was ejected into the shooter lane and game was still on. Game is set for 5 balls per game. Wondering why it did not end?

After Ball 5 drains, the Ball in Play lights go off but the ball continues to eject into shooter lane and game is not over. All rivets and wiper blades appear fine.

That did it! Jumper wire between Ball Count unit on the 7th position wire lug (green/red wire) and the game over relay coil (green/red wire). After 5th ball drained, Game Over. Now what? Does that indicate a short somewhere? Thanks again!

They are right beside each other in the main cabinet. Should I look at all the Green/Red wires in the game? Including the Backbox and under Playfield? Or can I narrow it down to a specific circuit on the schematic?

The Green/Red wires are bundled tightly between the Ball Count Unit and Game Over relay. Nothing loose or damaged.