I have a Westminster door chime. I need to replace the diode. What type of diode do I need.

I have a Westminster door chime. What type of diode do I need.

Where does this diode go?
How big is it?

Can you see any markings like 1N400x, where x is 1, 2 or 3 which would be my first guess. A 1n4001 would probably work. The x is related to breakdown voltage, so a 1N4001 is a 50 V breakdown. It's also a 1 amp diode. This is about 1/8" in diameter.

A 1n540x series is a 3 Amp diode and is about 1/4" in diameter.

Radio Shack should have them.