You are reading a single comment by @ObiWomKenobi and its replies.
Click here to read the full conversation.
ObiWomKenobi-
Maybe unscrew the black bell and have a look at the connections and the little hammer that strikes the bell. It's such a simple mechanism you should be able to identify which part is broken. My money is on the switch, maybe the contacts work hardening need bending back or it's more modern type with a little switch that has already given up the ghost.
Airhead
Most likely the switch failed or the bell hood has spun round. If you remove the cover of the switch and connect the contacts does it operate? If not then dismantle the whole thing and test it on a bench first because what you have there should last the half life of the universe.