just bought an hp pavilion laptop about six months ago... moved out of state- and something must have fallen on it- i'm not too sure. whenever i start it up, i get nothing but a black screen. all of the lights come on on the keyboard- and it sounds as if its booting up. i did buy a warranty- but i've got to take it into the store to get it looked at (which is a good 15 hour drive...) i'm hoping someone can help me- i'm not too computer savy- but i know the basics. any suggestions would be great... thanks

First, you need to know what actions would void your warranty. Actions like opening up a casing. Look around it and make sure there are no stickers on the casing side corners saying something like "if this label is damaged or removed the warranty will become void".

If you see no such stickers, I guess it is safe to open it and unplug and reinsert the graphic card.

Moving PC around can jerk loose the cards inside it. Believe me, I've seen graphic cards (although screwed to the casing) completely out of the slot, and hanging on the screw. This was caused by 20 min drive.
Doesn't have to be video card, Any card would do.
If you have on-board card, check the memory modules. Some OEM machines have "warranty void" stickers on the memory modules. In that case you'll have to press those modules in to seat them in. Be sure that you don't damage the stickers.