Specs:

Sapphire 4870
Asus PQ5 PRO
Thermaltake toughpower 750w
Q9450
G-Skill 2x2gb DDR2 800
Vista Home Premium 64-bit

I have this build up and running with a Ati x600, because when I try it with the 4870 installed my mobo won't post. Every thing turns on and the 4870 fan sounds like it's running at 100% so I know its connected right. Also, there are 4 red lights on the card and the one farthest from the outside is on, which is labeled as D1603. I've read that this means (The External power connector B was removed). But I've tried connecting it with different cables from my PSU(with the same results), so I know thats not the problem. I"m planning on RMA the card, but I wanted see if there is a fix first. I haven't updated the bios yet, do you think that would fix it?

any suggestions are very appreciated.

You can try a BIOS flash, however that sounds like the card is bad. (also be sure to remove old drivers first)

Well I don't really want to flash the bios( mainly cause I don't know how, but I guess thats what google is for). So I think I'm going to RMA it.

P.S. I don't have drivers for it installed, since it won't even start up with it in. Do you think if I installed drivers for it with my x600 in and then started it up with the 4870 it would work?

Most likley not, but make sure to remove the X600 drivers first, before installing the new card. Also check that the power connectors are fully seated (and all appropriate ones are plugged in)(ie the 2x6 pin power leads are connected fully)

P.S. Asus should have a flash util on their site (need to drill down to your board).

Also be sure to turn off X-Fire (if there is an option for it in the BIOS)(I don't know much about Asus tho, I use Gigabyte)

However the GPU could have been DOA. It happens every now and then (ordered 50 cards for work, 5 DOA)

Removing the drivers for the X600 card probably won't help since most ATI drivers work for all of their current video cards. The least you should get is Windows going to the default video driver, but since it doesn't appear to have happened I'd guess that the video card is bad.

I actually never installed drivers for the x600, and I've checked that the 2x6pin power leads are connect fully, multiple times. But I'll check out the crossfire thing and the Asus flash util.

Thanks for the suggestions.

most companies have about a 5 % doa rating or w/e it is... some have lower and some have higher but that's about average... at least as far as i know if i'm wrong please correct

And I'm probally one of the 5%, lucky me