New computer won't go to bios when GFX card is in and powered

[ColdAsIce]

PC Spec:

Intel Core i5-3570K 3.40GHz (Ivybridge) Socket LGA1155 Processor (77W) - Retail £154.16
MSI HD 7850 Twin Frozr III OC 2048MB GDDR5 PCI-Express Graphics Cards
Samsung S24B300HL 23.6" Widescreen LED Monitor - Black
Gigabyte Z77-D3H Intel Z77 (Socket 1155) DDR3 Motherboard
OCZ ZT 550W '80 Plus Bronze' Modular Power Supply
Toshiba (7K1000.D) 500GB SATA 6GB/s 32MB Cache - OEM (DT01ACA050)
Xigmatek Pantheon Mid Tower Case - Black
GeIL Black Dragon 8GB (2x4GB) DDR3 PC3-12800C11 1600MHz Dual Channel Kit

When I power the PC it won't go to the bios if the GFX card is being powered. Doesn't matter if any monitor cables are connected or not. I have to remove the power cable from the GFX card before it will boot.

So I can get to the bios via the motherboard on-board GFX. I checked the settings and tried disabling on-board graphics, hoping this was overriding the GFX card but then I was unable to get to bios at all. Had to clear CMOS and then start again. I have tried both HDMI and DVI on the GFX port.

Currently installing Win 7 using the on-board graphics and then will try installing the graphics drivers once in. Worried though because obviously I cannot even get to a bios screen when the GFX card is powered currently.

Sorry for the rambling post been troubleshooting for ages

 

[ColdAsIce]

If its a new gfx card would you be able to try in another computer?
Did you build yourself?
Are all power cables inserted correctly for motherboard?
Does your mobo have another pci-e lane you can try it in?
Also have you removed card and reseated?

If you are able to try in another pc and it gives the same problem, you have your answer.

Tried GFX Card in old PC, works with no problems.

Tried disabling onboard Graphics on the new system and setting first load option to the PCI Express slot. Still nothing on boot. Won't even show bios. (Also tried the secondary PCIe slot.

Posting this message from the new PC, onboard graphics etc all working fine.