How to troubleshoot a dim/dark LCD after being dropped?

MBP a1278

My MBP Pro was dropped and now the LCD screen will not light. I can tell that there is an image there, when I shine a light on the screen. I've done all of the elementary trouble shooting. I really think that it is a fuse, or the GPU, but how do I go about troubleshooting and replacing? Do I replace the whole logic board?

How can I find a diagram of my MBP a1287, to locate the componets?

I can't find any forums on how to proceed. I don't think it's necessary to replace the cable and LCD screen, as I've found on some other threads.