Why won't my Radeon HD 6950 connect to my monitor?

Recently, I have been putting a small system build together with a Radeon HD 6950 1GB, as the graphics card. When I tried to boot up with the integrated graphics, it was fine, but when I booted off the 6950, nothing. By the way, I have went into the BIOS and turned integrated graphics to off. I have checked my cables and the graphics card turns on, just does not connect. One thing is that when I go into BIOS and on the PCI-E slots, it says nothing… Also, the graphics card is clicked in.

My system:

Intel i5 3570K CPU

Intel copper core low profile heatsink fan

Intel DH77DF m-itx motherboard

Curcial 8GB (2x4GB) DDR3-1333 PC3-10600

Asus - Radeon HD 6950 1 GB

Mushkin 120GB MSata SSD (Boot drive)