Help! installed my new HD5770 Asus, but not getting any video feed.

So i followed the instruction as written in the guide book provided with the card:

• PC power off.
• took out my old GFX from my 1 pci-e*16 slot.
• put the new HD5770 in it well.
• screwed it as needed.
• hooked it's back power aux to power from the psu(original cable from PSU->MoBo, with extension that hooks up to the GFX cable which goes straight from there into the GFX card(it has another extension, i'm assuming to continue the power line, or should it be hooked up to electricy too?) *connected my screen to the DVI out put, and even my 2nd screen to the VGA output.
• power on.

The PC starts running, all the fans and stuff turn on, but i get no feed of image from the screens, and i think it doesn't do the regular sounds the it chuckles in there when i startup. nothing happens. i try to turn it off, i can't. not even with a long press. i have to turn it off from the back switch.

tried a few times stays the same.

what could it be? did i do something wrong? my PSU is 500W that should be enought i think. the GFXs' fan works.

EDIT: ok, i think it's not the GFX, but the F3 hard drive that's causeing the problem, so here's the full story of what happened: with the F3 connect, i get no bios at all. however, if i connect the previous Hard Drive (via the same connectors) bios does start up. (HD5770 + old hard drive = works) could i have broken the new f3 somehow? it worked at the beginning, before i put the HD5770, i replaced the old Hard Drive with the new F3, and installed windows. everything worked fine.then, when i went about replacing the GFX, i took the old one out, and attempted to put the 5770, but the position of the hard drive was awkward and blocked it a little(the 5770 is much bigger than the previous GFX i had) so i took the hard drive out and lowered it down a slot. i may have accidently grabbed it from it's bottom, perhaps touching the disk. then, when it was all set i tried to turn on the PC and got nothing. now if i put the HD5770 with the previous Hard Disk, the PC boots (doesn't go to windows because it's not configured good now, but boots and i can see it on the monitor via the new HD5770) if i messed it up can i still try to claim the warranty? could it just be defected and not my fault? how gentle are these things? why don't the come better protected?