AMD Radeon 6950 graphics card not working on Gigabyte GA-Z77X-UD4H

[Ghost2609]

Hey so my friend gave me his old Gigabyte Z77 motherboard and I have a XFX Radeon 6950 graphics card and it doesn't want to work on this motherboard. It gives me a black screen. At first it gave me a A6 or Ab code but then when I tried another graphics card (my old nvidia 9500gt) it showed me AE on that but I think that's because of windows because it couldn't load probably because of the hardware changes but I got into the bios. Then when I plugged in the radeon again it gave me the same AE code but still a black screen. If I reset CMOS it goes back to A6/Ab. Also the integrated graphics also work. I got everything plugged in. This radeon gpu works on my old motherboard. So motherboard isn't the problem and neither is the graphics card kinda cuz they both work but don't like each other or something. I have an Antec 550W 80+ Gold I know this gpu needs quite a bit of power but I calculated everything that is essential and plugged in and it should at least go into the bios. Also tried setting PCI to priority in bios and disabling on-board graphics. Also tried booting it from a usb drive with the radeon still nothing. Any suggestions?

 

[cin19]

Recommend to check your MB BIOS version, if it does not have the F2f, update the BIOS. https://www.gigabyte.com/Motherboard/GA-Z77X-UD4H-rev-10#support-dl-bios

 

[Ghost2609]

Recommend to check your MB BIOS version, if it does not have the F2f, update the BIOS. https://www.gigabyte.com/Motherboard/GA-Z77X-UD4H-rev-10#support-dl-bios

Hey sorry for the late reply. So I tried to update the bios to F2f and then to F2h too but still a black screen. I also tried many different graphics cards from friends like GTX 960, 1050 ti, radeon 7770, 650 ti, radeon rx 570, gtx 550 ti. Everyone of them worked on the motherboard except 550 ti.

 

[Ghost2609]

I also tried my card on Asus P8Z77-V Pro because I thought it was a Z77 chipset thing with this card. But it worked there. Now I'm really curious why wouldn't my card work on the Gigabyte mobo.