Gigabyte HD 7950: No display

[Breakfast Cyborg]

So I just finished building my first pc, and everything works fine without the graphics card installed. However when I try to use the card I can't get a signal from it to the monitor despite the rest of the system seeming to boot up ok. I've tried just about everything I could think of to fix this, like using different outputs on the card; switching the initial display priority to PCI-e; disabling the internal graphics and using a different cable and monitor. Using the other PCI express slot on the motherboard also produces the same result. Is the card dead or am I doing something wrong?

Specs:
Motherboard: Gigabyte Z77X-D3H Rev 1.0 (f10 Bios)
CPU: Intel Core i5 3570K at stock
SSD: Kingston Hyperx 3K 120GB
HDD: WD Caviar Green 1TB
RAM: Corsair 8GB CL9 1600Mhz VENGEANCE LP
Graphics Card: Gigabyte 7950 3GB AMD Radeon
PSU: Corsair TX650M

Any help will be much appreciated!

[Chromoblaste]

have you thought to connect the power cables on the graphics card? It happens even to those who often ride pc;)

[Breakfast Cyborg]

Yep, everything seems to be connected up OK. All of the fans on the graphics card spin up etc.

[Breakfast Cyborg]

Well I managed to find a way to get the card to work - I set the PCI ROM priority to Legacy instead of EFI compatible ROM. Does this mean that the card is functioning properly / will work at full capacity?

[Chromoblaste]

Just do a 3Dmark bench for example and compare the results;)