GPU doesnt work with my motherboard??

[j.burggraaff99]

I have a:
Palit 980 TI super jetstream
ASRock H77 Pro4-M
I5-2500K

My problem is that i cant get my GPU to work. If i have it as my main boot display output it doesnt display anything. But if i have my onboard GPU as my main boot display it then allows me to do anything i want. So i went into windows, looked in Device manager and it says that my GTX 980 TI has a yellow triangle on it, with code 43.

I used DDU, then installed nvidia software to install drivers. Did not work.
I used DDU, then manually installed the drivers. Did not work.
I used DDU, then looked for a older version of drivers did not work.
(Display Driver Uninstaller)

I have a AMD hd 5800 and that card works in my system.

So my question is:

Is my motherboard the fault?
Is my GTX 980 TI the fault?
Is my PSU(Seasonic 620 W) the fault?

I'm from the Netherlands so my english isnt the best.

 

[camieabz]

Is the BIOS set to allow the gfx card to be used (over the onboard gfx)?

 

[j.burggraaff99]

Is the BIOS set to allow the gfx card to be used (over the onboard gfx)?

I can set the bios to start from my pci Express, but if i do that my computer does not display anything.

Also i can choose my PCIE1 Link speed, from Auto, to gen1, gen2, gen3.