I recently was tasked with fixing up a Stern World Poker Tour that had come off route. The game had a number of issues, the first of which was that certain targets would not reset. They would pop-up, but fall back down. Some research indicated this was a known issue that Stern released a service bulletin to address. But I soon found out my problem was deeper than that, and several things were wrong, including a broken bolt holding a coil stop, and the wrong plunger assembly used on one of the drop targets. In this video series, I outline how I identified and solved the problem. Here are some pictures of the work that was done to fix the broken bolt.
Fixing drop targets on Stern pinball games (World Poker Tour)