well, to fix it yourself, if the light tube is burned out, you'd need another identical one. If its a loose wire... you could do it yourself with a screwdriver (probably). I've only been inside a laptop lcd, but from that experience, if you crack it open, be VERY careful with any boards that are attached directly to the screen itself.
The light tube itself should be easy to find, probably on the side of the screen. In the laptop I trashed, there were two wires going to it that were plugged into a circuitboard. if those are loose, that could be your problem. Hope that I helped somehow.
edit: if you have the money, take it to a repair shop, because if they screw up, they're liable. if you screw up, you're out $100.