My GPU doesn't display when its on PCIe x16 channels, even though they're working

[SenditMakine]

I recently bought a Huananzhi x99-F8 motherboard and when I first used my R9 280x TOXIC in this mobo I was only able to run it on the 3rd PCIe slot (x4), the first and second slot (both x16) simply gave no video and a long beep meaning it was not able to detect the video card (the cpu doesn't have a integrated graphics card, it even displays the debug code 9C) After messing arround with the BIOS I was able to make all slots work but only on x8, when I change it to x16 the same error happens. I already tested all the channels with a low budget GPU, all slots worked even at x16. I really have no clue on what's going on since i tested this GPU (R9 280x TOXIC) on another mobo on the PCIe x16 and it worked fine, any idea on what I should do? Thanks in advance!

 

[Rei]

Try borrowing another GPU from someone else (your friends, parents, children, neighbors, dog, cat, etc.) & try it on your mobo if it has the same result. If it does, then the issue could be with the mobo. Also try updating the firmware of your mobo too. Might as well update your GPU's driver to ensure compatibility with your mobo.

 

[95Viper]

Use your original thread, as, it is the same topic : My R9 280x TOXIC (2x8-pin) doesnt display when its on PCIe x16 channels