What's the difference between "It's broken" and "It broke"?

A reader asked this question:

I have a question about the usage of "break". What is the difference of "The TV set is broken." and "The TV set broke." I've been unclear on that for a long time.

"The TV set is broken" is a statement about the situation of the TV right now. It doesn't work.

"The TV set broke" is about something that happened in the past. It used to work, but the it "broke" and stopeed working.

There are many situations in which you can use either one. For example, if you have a TV that's broken now, you can tell someone "It's broken" or "It broke." 

But there are other situations in which you can only use one. For example: 

• if you buy a new TV and it doesn't work when you buy it, you can say "It's broken." But you don't know when it stopped working; maybe it never worked since it was made. So you wouldn't say "It broke."
• If your TV broke but then you fixed it, you can say "It broke" but not "It's broken."