Troubleshooting Doorbell

Hello,

Let me first say that I am not very experienced with this. I am trying to fix my parent's doorbell since it stopped working about a month ago. What I first did was remove the doorbell button and test the wires with a multimeter, which was set to AC. There were two thin wires attached to the back of the doorbell. I had the black test probe on one wire and the red test probe on the other wire... Showed no voltage. I switched the probes around and still showed no voltage on the multimeter.

What I did next was look for the transformer, which took some time... Finally located it in the attic. Used the multimeter on the transformer's terminals and read about 18 volts coming out of them. Given this, I assume the transformer is good.

Then I went to the chime itself and tried to use the multimeter on it. The chime only had wires connected to the "Front" and "XFMR" terminals on the chime. With that, I assumed the only way to check them is to have one test probe on "Front" and the other on "XFMR". However, I read no voltage on the meter. I interchanged the test probes and still read no voltage...

Given what I have been able to do so far, is it safe to say that there is some type of break in the line between the XFMR and doorbell button? Is it also safe to say that there is a break in the line between the XFMR and the chime?

Thank you all in advance.

 

Break in the line..... maybe but doubtful.

You are dealing with a series loop. If the button is not pushed in there will not be any voltage at the chime.

Disconnect the two wires from the chime. Set your meter to ohms and check from front to xfrmr for any continuity. My guess is the chime unit is open/defective.



You could try moving the front wire to the rear and see if that works.

 

Before you buy a replacement chime, jump the two terminals on the push button with a piece of wire or a paper clip. You may find that the chime works fine and the problem is with the push button.

 

The wire is probably 18 gauge of smaller and solid. Solid can break and the insulation will conceal the break. Remove a wire, hold the cable, grab the copper portion with a pair of pliers and pull. Re-terminate and move to the next wire.
I saw it quite a few times, often on smaller conductors but often enough on 18.

 

Thanks all, I first checked the chime for continuity as PJmax recommended and found that there was none between the Front and XFMR terminals. Then I checked the continuity between the Rear and XFMR terminals and found the connection was still good. Given this, I moved the wire from Front to Rear. That solved the problem! Not as hard of a fix I originally thought it would be. Thanks again!

 

The only difference using the rear instead of the front is that the front is ding-dong and the rear is usually just a ding.

More than likely the front coil burned out because the pushbutton was shorted or stuck in.
Actually a pretty common problem.