Hey neighbor- see this post as a possibility. There is also a rocker switch that rides the outside (top I believe) of the head assembly that might be the issue

https://pinside.com/pinball/forum/topic/bop-clubnon-20/page/5#post-2713196

Maybe Andrew and I can come look at it tomorrow - I have had mine apart right to the bones ...

Found this quote that I copied into Evernote during my restore

US Cincinnati, OH
3y  1,052  15  2/0
The small head motor relay board mounted near the head on the underside of the PF typically will have cracked /cold solder joints on the header pins. Re- flowing those pins usually solves a lot of head homing issues.

This thread shows "how" that switch I mentioned "knows" what position the head is in

https://pinside.com/pinball/forum/topic/bride-of-pinbot-head-turns-wrong-way

The image below is the switch at the top. this entire assembly does NOT move
The switch and this entire frame sits still
The square head/face assembly rotates AROUND this and that rocker switch rides on a flat portion with "notches" in it

rocker_(resized).PNG

This image is the face assembly that rotates around it - this is the piece that stationary rocker switch comes in contact with and "tells" the machine at what position the head it at. I assume that if this switch is bad, the machine can't know where and when to stop?
I've got a spare I can bring over if that is the issue

Head_(resized).PNG

Also check to see that you don't have any acid damage from the batteries. When I bought my BoP, the head would rotate more than it should, and I had to re-pin the connectors situated below the batteries that had been leaking.

Hey VolunteerPin....did you get this resolved? if so, what was it...