Doorbells are not particularly complex devices. They have a power source, a low voltage switch, and a chime. These are the only three places that problems can occur. So, repair of most doorbells consists of replacing the defective part or fixing a loose connection. Unless you have an expensive doorbell system, don’t try to repair anything because it’s just as cheap to replace it.
If your chime develops funny sounds or incomplete rings, you need to replace the chime. There will be a box hanging on a wall somewhere central to your house. This is your doorbell chime. Turn off the breaker that controls the device.
The plastic or metal cover should just snap off. There will be 4 or 6 screws holding it to the wall. Remove these. Before removing the wiring from the device, open the new one. Read through the directions completely to make sure that you understand where the wires that you are getting ready to remove from one unit fit onto the other one.
There should be 4 or more wires connected to the chime. Two thin ones are the leads to the button by the door. If you have two switches connected to one chime, you will have 4 of these wires. Each button is supposed to ring 1/2 of the system. That way you get two different rings to know which door to answer. Make sure that your new unit is designed to do this before you install it. If it should and doesn’t, then return it for one that does or vice versa.
Remove these low voltage wires and attach them to your new unit. You should also see 2 or 3 heavier wires. These are the power source for the chime. Disconnect these wires and reattach them to the new chime on the proper contacts. Fasten the new unit to the wall with two screws for now.
Go turn on the power. Push your doorbell button or buttons. Make sure that the device is chiming the way you want it to do. If you have reversed the wires for the two doors, just swap them and test again. If the device worked as desired, finish attaching the new unit to the wall and place the cover over the workings.
If your bell doesn’t make a sound when you push the button, it could be a switch. Test the other doorbell button if you have a second one. If it doesn’t work, make sure the breaker is engaged. If it is, remove the cover from the chime with the electric off and see if there are loose wires. After tightening the wires, repeat the test with the power back on. If both buttons still fail, it’s probably your chime. Replace it in the same way as above.
If you only have one switch and the bell doesn’t work, remove the switch by removing the two screws that attach it to your house. Remove the wires from the back of the switch and touch them together. They are low voltage. You don’t have to worry too much about getting shocked. If the bell rings, replace the switch. If it doesn’t ring, follow the above procedure. It will either be a loose connection or a bad chime.
Should you have a problem after you replace the chime with no sound, check to make sure that you have wired it correctly and that the breaker is working right. If they both seem to be fine, then call in a professional.