There are a few things to try.
First, connect an external monitor and see if the image comes up there without any video defects. If it does, the display or its cables are bad but the basic video hardware on the logic board is OK.
If you get no image on the external, the video hardware could be compromised.
We need to know the exact model MBP, as some models have a defective video chipset for which there is a free repair up to four years from date of purchase. As your computer wont' start, upend the computer and look for the model number (starts with "A") in the tiny print silkscreened text on the bottom near the edge with the display hinge
If the "A" number is A1226, A1229, A1260, or A1261, the computer has the potentially affected nVidea 8600M GT chipset. You'll need to take it to an Apple Store or AASP--they have a special gadget that verifies the failed part. It must show failed with that test to qualify for the free repair (a new logic board).
If the model number is worn off, I'd try the Apple Store anyway. Al they can do is say no. Print out this article on the repair and take it with you:
http://support.apple.com/kb/TS2377
Will the computer boot from the original system disk?
