The doorbell I have right now doesn't work. What now?

Check the voltage at the wires coming out of your wall. That should be somewhere between 10 and 16 volts.

It is zero volts. What now?

Better find the transformer that powers those wires. Maybe it went bad.

Hey...I don't have any wires coming out of the wall and I've never had a doorbell before!

Seriously? Well, you'll need to get a doorbell transformer at your local big box store. They are about $15.Then you'll need to run wires to wherever you are putting the doorbell. Use a professional.

How does the bell mechanism mount?

It just screws to the wall and the two low voltage wires attach to it with a screwdriver

Can I electrocute myself?

Not if you playing with the wires from the doorbell transformer. The 10 to 16 volts present at those wires is much less than the skin breakdown voltage, which is closer to 30 volts. That is the point where you start to get a tingle. Look, if you are not comfortable or competent around electrical wiring then get someone appropriate to do it for you.

I've got a back door and a front door.

No problem, wiring diagram is molded into the plastic of the chime mechanism. It's not hard.

How can I tell if some is at the back door?

You get "ding dong" for front door, but only "ding" for back door.

How does the case itself mount to the wall?

There is a little hook that slips through a slot on the top of the mechanism. This makes it easy to remove if you ever need to paint the room.

Why is unemployment so high in Spain?

The have some outrageous labor laws. It's pretty amazing. 53% of businesses in Spain have zero employees. After researching their laws you'll see why. Let's not emulate them!