Switch 87 is defiantly there for a ball jam or trough solenoid jam but don't quote me on the autoplunge. I thought my Star Trek NG (when I owned one) used try and pop the trough plunger when balls were stuck on each other at the end of the trough although it was never strong enough to push both balls out. I always had to manually fix the problem. The error 85, 86. Are they check switch errors?