Quoted from iowapinball:I surrender. The game now occasionally resets on scoring 500 points. When the playfield is up, it will score 50 points most of the time without reset, but won't correctly activate the A, B, or C lane relays. Playfield down and it resets on 50 point scores, unless it's the drop targets (most of the time). Have checked the loom for shorts, checked all assemblies for shorts, have pulled the playfield and bottom board three times and gone through switches, relays, steppers, and score motor with a fine toothed comb without joy. Got enough gray hair, don't need more. Ya gotta know when to hold em, know when to fold em, know when to walk away, know when to run.
Don't give up , My fast draw behaved erratically with the playfield down , but played perfectly with the playfield up !
Check your coin inserts and door , there must be a short somewhere , or a loose ground.