OK Daddios, I am reviving this old thread because I am dealing with the exact same issue right now. I have the schematic, and I have gone through everything above. When you press the credit button, the game resets everything as intended: all score reels at zero with switched open, bonus counts down if there is any, etc. But the score motor just keeps chugging. As with the OP, if I manually disengage the reset relay, you can play a normal game (I'm pretty sure - there might still be an issue with the ball count unit, but I manually made sure that was in game start position).

So. I have checked every switch that makes the score motor run (first pencil circle on schema). They all are gapped and open/close properly. I then tried turning on the game, but before starting a game, I manually tripped every relay that runs the score motor. Most ran it and then it stopped. However, when I trip the reset relay the endless motor running begins. Ok that makes sense. The same thing happens when I trip the coin unit. ruunrunrun. The start up sequence in the manual sez that the coin relay trips the reset relay, so that makes sense, so WTF?

I checked 8e on the score motor. Fine, I checked 1g on the score motor (connected to the coin relay). Fine.

As the OP said: This thing is killing me!!!!
Help!

PXL_20210708_195212443_2 (resized).jpg

One more bit of info (also for a bump): When I remove the middle Jones plug, it stops the score motor.

Yep. Did that. Cleaned that. Gapped that. All 18.

Every single one opens as intended. Next time I'm out there I can take video. I business carded all of them one by one too.

It does not. I have to push it manually to stop the score motor and start a game. I really have done every single thing you and the other helpful dudes have suggested. I also checked all the switches that run the score motor.

As the OP also said, this thing is killing me.

I do have a question regarding that part of the schematic. When I close the coin relay switch, the reset relay trips. That's what the manual says is the start up[ sequence. Could my issue be there?

Also, I know the bonus unit is supposed to increment from zero to one at the beginning of a ball. That is supposed to happen AFTER the reset sequence is through, right?

Thanks for your patience.

That's going to be one of my next plays when I go over there again on Tuesday. I was just hoping for a back up plan in case... trying not to make make too many separate trips. Thanks for sticking with me.

1. I card all 18 switches; score motor runs merrily on, reset relay still engaged.
2. I contemplate just taking this thing out behind the barn and shooting it...
3. I remove the middle jones plug from the head. Stops! Ok must be one of the score reel zero position switches... but they're all carded!
4. I take each score reel unit out and test continuity at the connection for each blade of that top switch...
5. On LITERALLY the 16th one, I find a hole worn in the bottom of the plastic insulator covering the solder joint on the upper blade. The lower blade doesn't have an insulator there because it looks like it's been resoldered. F'in A! Wrapped a bit of electrical tape around the uninsulated joint, and bingo! Winner winner, chicken dinner!
6. I thank Howard for sticking with me and being persistent about being right!
7. Now I gotta clean the sticky player and ball count units.