Hi everyone, I recently thought it would be a smart idea to volunteer to replace the failing HDD on my friends Macbook (white, late 07 model), since she could get a higher capacity than 120GB this way, as opposed to getting a replacement at the Genius Bar. I went on ifixit.com, since I was able to change a couple of components on my 1st generation Macbook Pro without much trouble, and followed the guide step by step. Now, I am no rookie with this stuff. I even used to work at an Apple store, but as a specialist, not a genius. However, when I did everything (and it would seem that the installation itself was done properly), the computer screen would remain off once I booted the computer. I tried changing it back to its original drive to see if I could at least get it to boot, but the same thing happened. Nothing on the display. I tried starting up while pressing C to run from the Snow Leopard disc, I tried starting up while pressing Option, I tried everything I can think of. I am running out of options and I have no clue what to do. Is there something I should have done before putting in the drive? Does anyone know what could be done, aside from taking it to the store and paying the $200 for an HDD replacement? (my former co-workers at the GB seem to be MIA for this ) Any help you guys can offer would be greatly appreciated. If I dont fix this, Im pretty sure my friend will murder me, or at least rub this in my face for a looooong time. Thanks!