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This is a conversation about how a doorbell system works, what can go wrong with it, and how a broken chime is replaced. Every home with a doorbell system has a transformer. That transformer is powered by 120 volts AC and converts it to 16 volts AC, which is what the chime needs to operate. One of the screw terminals sends power down a wire to the chime, and the other wire carries power to the location of the push button. On the back side of the chime, one wire ties into a screw terminal, and the other wire goes up to the transformer. When the button is pushed, the electricity goes up to the chime and makes it operate. There is a little plunger inside the chime. When the button is pressed, the plunger is pulled in magnetically, and when the button is released, the plunger strikes the chime and makes the noise.
Somewhere in this system there is a problem. It could be with the transformer, the chime, or the push button itself. Connecting everything together is wiring, which is really thin, so it could be broken somewhere along the line. The only way to know is to find out.
In the basement, the transformer is tested to see whether it outputs 16 volts. The probes are used to test the voltage, and the reading is 18 volts, which is considered perfect. Next, the chime is checked. The chime is painted over, and the plunger has fallen off. The contacts are frozen and not moving. To be sure, the voltage is tested again while the button at the front door is pressed and held. The reading shows 16 volts when the button is pressed, which means the transformer is good and the button is good. The chime is not so good, so it is going to be moved, and it will be replaced when it is moved.
The new chime has a classic look, but on the inside it is all electronic. It comes as a wireless and wired version, and the wired version is used here. The volume can be controlled because it has a speaker, and there are 16 different sounds to choose from, including birthday music, holiday music, and Fourth of July music. The new chime is mounted in the kitchen. When the old chime was removed, a splice was found where all the wires meet. The wire from the transformer downstairs, the wire from the front door, and a wire from the back door all come together there. Because this is all low-voltage wiring, a splice can be made right there. The new wire is attached, run through the wall into the stairwell, and across the top of the stairwell to the new chime. Holes are drilled, and the wire is pulled through. Because this is an electronic doorbell chime, diodes are required at the front and rear buttons. With all the work done, the new chime is tested by pressing the button, and it sounds really good.
Questions are then asked about the work. When the old chime is opened, the wires can be identified by the markings on the chime, which say front, transformer, and rear. A homeowner should put a piece of tape on each wire before removing it from the screw so they know where each one goes when the chime is put back. When testing the transformer, the optimal reading is 16 volts. A reading within about two volts lower or higher is acceptable, since digital multimeters are very sensitive and it is hard to get an exact reading. The diode is needed because with an old-style doorbell, electricity is sent to the chime only while the button is pressed. With electronic chimes, electricity must keep flowing to the chime even after the button is released so the whole tune can play, and the diode allows this. For personal preference, an old-school analog chime with a neat little sound is also liked a lot.