Hey guys!
I've very new to electro-mechanical machines and pinball maintenance in general. I started out as a vid guy, but after getting my first pin last year and watching the developments of Ben Heck's AMH I've found myself drifting over to the pinside.

The machine I picked up is a 1973 Williams Fun-Fest, while it has been running great it's suddenly having a issue with the end of ball bonus.

If the ball drains after hitting any target, pop bumper, switch, ect. that awards points the game will continually add 1000 points to the current player and not serve the next ball. I feel like the problem is in between the device that counts the bonus (I'm not sure what it's called or looks like) and the outhole relay, though I'm completely foreign to the world of EM and that's mostly a guess.

I can manually activate the outhole relay while it's looping and it will stop, serve the ball, and update the current ball count properly.

Any help hunting down this issue would be greatly appreciated! Thanks!

Did some more poking around inside the machine today. I found a relay labeled Bonus and if I manually trigger it the machine will stop looping, the relay locks on though and will only let go if I trigger the outhole relay.

I'm having some difficulties following the schematics, the color of the wires inside of the machine have faded pretty badly. Also who thought that orange with tiny red dots was a good idea, and why are they allow to live?

Got the issue fixed! (mostly)

There was some grim built up on the contacts of the score motor, and after scrubbing it clean with a toothbrush and paper towel the repeating bonus has stopped. I also adjusted the center switch of the bonus relay some, it appears to be the one that triggers the outhole relay, it wasn't making a very good connection.

The only remaining problem is after the 2nd ball drains and the machine serves the 3rd, it will get caught in a loop and keep trying to serve a ball even when there's not not in the trough. It will keep activating the serve solenoid until a target is hit.

I noticed the swing reel isn't counting down at the end of a ball, I have a feeling that might be related...