The AS stepper for the feature is the relay unit on underside of playfield that has its own jones plug so you can unplug it to adjust. There are hairpin clips on all relays to hold them on rail. Remove clip, unplug, adjust both switches on top and make sure stepper rotates every time you pulse coil with your finger. the 2 switches are the ones with leaves that make/break as the stepper rotates. If the stepper does not rotate there is a current thread on stepper rebuild.