Tim, if you don’t already have one, get the schematic for the game. It will make the debug work much easier.

The first photo you posted is of the knocker. Next to it are the two bells which ding when you score points. What makes them ding is the metal plunger that is inside the coil. When a current is run through the coil, it becomes an electromagnet and it shoots the plunger into the knocker or the bell, making the sound.

This board is also a great source for debug help. Do get the schematic though.

Alberto