Just got a NIB ST Pro. It played great for about 50-75 games, but then stopped registering hits on the vengeance ship when the drop target is down. Drop target still works fine and the ship rocks as it should when the drop target is struck. When the lock is lit, the sensor registers the ball passing the drop target and locks it in there as it should.

When the drop target is down, hitting the white target behind it is a dead hit. No points or progress towards vengeance hurry-up, and the ball is not fired back at high speed as it did before.

I looked around for a disconnected wire, but I couldn't see anything obvious. Most of the mechanism is hard to see, as it is above the board and below the vengeance ship. I don't want to pull everything out of there if I don't have to...

So if anybody can give me some ideas of what might have gone wrong or what I should be looking for, it would help me a lot.

Thanks, Pinside!

On doing a bit more research I think it is my upper opto that has shaken loose. Will try to re-seat the connectors when I get home tonight.

Ok so I checked the connections for the opto and it looks fine, it is emitting a red light but not registering when a ball goes through.

To replace the left opto how much do I have to pull off the playfield? Just the left side ramps, just the vengeance ship or both?