In what way is it bust?

If it's just not lighting up, there's pretty good odds it's the DC input jack. Replace that and you might be on your way again. And have you tried it with a different DC wall-wart? Wires for these things are pretty fragile, or the wall-wart itself might have died.

Or if you're using batteries, the battery clip might be loose or broken, or one of the wires to the battery clip might have bust. Another common problem which can be fixed fairly easily.