Gigabyte Radeon HD 7870 not detected by Windows 8 and/or Gigabyte Z77X-UD3H mobo

[decepticron]

I have loaded/updated my mobo and gpu drivers and bios, but have not been able to get a signal from my radeon hd 7870.

Things I've tried:

Using all available pci slots
Using every output (hdmi/vga/dvi)
Disabling integrated graphics in the mobo bios.
Rechecking all connections.

I'm pretty much at a loss. All of the fans are running (620w psu), but I've yet to see any output.

[deadman4168]

go to bios and Look for PCI ROM PRIORITY.....change it efi/legacy and try.

[decepticron]

I tried this with no luck .

This is my first build, so this is a bummer.

[deadman4168]

changed it to legacy still none ??

[decepticron]

Yep, the gpu is still not detected.

[choco_bn]

Update ur motherboard bios.

Test ur 7870 in another motherboard

reset cmos

switch dual bios on cm of 7870

switch pcie slot

test another gc on every slot pcie

[najiro]

I have loaded/updated my mobo and gpu drivers and bios, but have not been able to get a signal from my radeon hd 7870.

Things I've tried:

Using all available pci slots
Using every output (hdmi/vga/dvi)
Disabling integrated graphics in the mobo bios.
Rechecking all connections.

I'm pretty much at a loss. All of the fans are running (620w psu), but I've yet to see any output.

woah!! let me clarify something...
YOU UPDATED YOUR GPU'S BIOS??
you do know that it will kill your gpu when it fails right??
flashing gpu bios might look easy but it's not yet perfect like flashing a motherboard bios..
chances of killing the gpu is slim but the chance exist...
typical symptom is having a black screen while all indication of a running computer is seen like HDD reading/activity, no beeps and so on...