Black screen with XFX HD 6870 on Asus M3N78 PRO mobo

Jan Veenstra

Honorable
Aug 8, 2013
1
0
10,510
I recently bought an update to my 9600GT gpu.
When I installed the 6870, the pc starts up but there's only a black screen.
I hear windows starting up due to the windows sound playing.

My system is;
Asus M3N78 PRO
4 Gb Kingston
AMD X4 940
OCZ 600W Power Supply

So now I am wondering if it's the mobo or that the card is incompatible with my mobo so that it causes the black screen.
I've googled some and it says it can't be the PCI-e 2.0 caus that's backwards compatible.