Part 1. Removing the Chime Cover. Buy a new doorbell chime. You should be able to find one at your local hardware store, or at any home supply store. Shut off power to the circuit that the doorbell is wired to. You'll need to find the circuit breaker box in your house or apartment. Remove the cover from the chime.
Because 16 volts is the standard for most doorbell circuits and components, you may be able to replace a defective chime box without replacing the transformer.
Exposed to the elements, doorbells rust and get dirty after time. Clean yours up before replacing the bell or chimes unless your heart is set on getting a nicer one
Unscrew the doorbell button to remove it from the wall. Loosen the screws on the back of the button and disconnect the wires. Then touch the two wires together. If the chime rings, the button is bad.