Thinking I might have this issue also. My buddy who reads schematics wat better then I is going to look today and see. I did have a pretty successful weekend though....took this $100 "close to parts" machine and got it working fine except for 2 issues. The bonus stepper and ball index relay not on the same page all the time and the Jokers don't register a "hit" on 10 points to light them up. I can manually trigger the coil on each and it does what it should, registers 1000 points and all 4 give an extra ball. So it's not the standups that are the problem.