Just wanted to bump this thread -- having the exact same problem as the OP but the crossbow goes about 1/2 of the way out before auto firing. It came this way out of the box and the v1.19 update didn't change anything. I've tried the above ideas -- button is working, switches are working, crossbow moves fine in crossbow test. Nothing yet.

Has anyone heard back or fixed the issue?

I'm consulting Stern and will report back if I hear anything on that side.

Thanks!

Oh man. Why is this bow so cross? I'll definitely report back my findings. The only other problem I've had is the "Check Switch 60" error v 1.19 was supposed to fix. Funny story: Switch 60 doesn't exist.

I believe I've repaired the crossbow! (Stern still hasn't gotten back to me). The crossbow switch #52 which tells the game the ball is loaded in the crossbow was the problem after all. The switch actuator was physically hitching up and not letting the ball activate the microswitch properly, thus not activating. That meant when I depressed the switch with anything but the ball it worked (like in the switch test, or during a game, with my finger).

It also meant that the ball search was actually what was causing the crossbow to swing out and fire.

It was a silly oversight. But it did take some serious switch actuator adjustment to get it to work just right.

And just in time for the lone opto board to give up the ghost. Argh! It' getting a TON of plays in the office so let the stress testing continue.