Macbook Display problem, why is screen completely white?

Okay, so here is my problem. I purchased a brand new i7 2620M Logic Board, that works!!!

Well atleast it did at one point. I turned it on, no problem.. I then decided to add in the new RAM that i bought (TWO 4x2) 8GB

Turned on, everything was fine.. I then wanted to add the 1 TB Samsung HD..new also..

When I placed it in, turned on the MBP i was hit with the white screen w/ the question mark..

Forgot to add the OS to the HD.. anyways.. i put back the old one, but then i accidently unplugged it while the MBP was on.

Quickly put it back in.. it froze for a lil, then turned off. I turned it back on & now there is nothing but a white screen.

I can hear everything boot up, chime, & I am even able to hear when it gets to the main log in screen..

so MBP still works internally.. My problem is that all i can see is a white screen..

Also there is a slight burn mark on the logic board where the display plugs in. But i assumed that the burn mark wasn't a big deal since the screen still lights up & turns on. I'm just not able to see what is going on.

PLEASE HELP. I spent almost 800 dollars on upgrades..hate to see it go to waste.