Monitor no signal with graphics card


TS Rookie
Recently I built an all used pc. After hooking everything up I have found the my monitor detects no signal when I'm using my graphics card. But my graphics card fan spins and its light comes on. However it works fine if I boot my without my graphics card in it and use onboard graphics. I dont understand as my gpu fan still does spin.
My specs are
Motherboard: gigabyte ga b75m dh3
Cpu: i7 3770
Graphics card: xfx rx 560 2gb
Psu: 500w evga 80 plus
Ram: 16gb 4x4 vengeance lp

Cycloid Torus

Stone age computing - click on the rock below..
Review 'settings' / 'setup' in mother board manual which you can get from maker's website. Confirm it is set to something like PCIe for graphics if you are using a discrete card.

If that checks out confirm that 6-pin additional power is properly connected.

If that checks out, confirm your graphics card is compatible with this motherboard.