I doubt its in the stepper it basically cannot be, thats not how the jones plug switch could ever work to make rhat change. The stepper sends a signal through every contact at every rotation. Its whoch contact and which switch closure on another ray that determines this. You need to go find where in the schematic the jones plug program to advance one two or three is actually executed. You also need to look hard at the jones and make sure wires and contacts look good.

Always remember to interpret others advice through your own experience and the manual and schematic. I own and have extensively restored this game so I am posting because I think your looking up the wrong tree... but I did not go through schematic so i could be wrong. Just FYI.

Schematic and manual are both on IPDB. Also- manual is incredibly informative and very very packed with useful info. Not sure if your using them but you absolutely need to be doing so.

My point is that the advance every x switch is failing. It ALWAYS sees an advance every X and the fact that yours ADVANCES at the wrong interval DOES NOT mean there is any issue in wires from the spinner. Your wasting time. A switch or another component had failed to BREAK that connection. The fact it works on whatever number of spins it does now, indicates that somewhere there is a switcg stack or contact that should be rerouting the signal and ignoring the trigger your seeing it fire at. It failed to take the command from the jones plug change. Its not the spinner or highly unlikey to be so.

Maybe I am wrong. I will not post again so as to leave this alone. Maybe its late....