This has plagued me since I got this unit and continues to rear its ugly head. 74 Strato-Flite yet again. The bonus wheel steps up and adds bonus and when ball ends it counts back for score and then lastly... resets from 0 to 1000 (first step) to start a new ball. If it fails to move to the 1000 position to restart a new ball the score motor continues to turn and whole machine goes through multiple, sometimes endless, recycles until power is turned off. I have spent hours adjusting springs, taking mechanics apart and cleaning and adjusting everything. I was convinced it was a bad coil but it seems to pull hard enough most of the time.
What I do notice is that when it tries to step back up the coil only move a tiny bit, not enough to push the mechanics ahead. Usually after a couple of rounds of the score motor it will do its job. When I push a target to advance it, the coil is quite robust.. so I think the coil is OK.
It is a contact on the score motor which pulses the coil to step up.... Could this be weak or too fast????
Any thoughts would be great... Thanks