I recently purchased an ASUS Matrix Platinum AMD 7970 from OCUK. I have finally got around to setting this up in my current PC. When I have tried to Boot into windows I am not able to see anything being displayed.....can not even get to the BIOS. I believe it is just hanging 
My current PC Specs are the following:
Corsair Hydro Series H100
Intel Core i5-3570K
Gigabyte GA-Z77X-D3H Socket 1155
Samsung 128GB SSD 830
Patriot Viper "Black Mamba" Generation 3 16GB (2x8GB)
Seasonic G series 550w '80 Plus Gold' Modular Power Supply
When everything is plugged in I can see a set of green LED lights on the graphics card.
I have tried all 3 PCI Express slots, no difference.
Removed all Hard drives / DVD drive, 1 stick of RAM, and any connected via USB, still no difference.
Is there anything else you guys think I should be trying? I know this graphics card requires more power than my current ATI 5850 but I am sure 500W is enough from the Seasonic PSU
I am back to using my old graphics card for the time being which is working fine.
Is it time to contact OCUK and get a replacement?

My current PC Specs are the following:
Corsair Hydro Series H100
Intel Core i5-3570K
Gigabyte GA-Z77X-D3H Socket 1155
Samsung 128GB SSD 830
Patriot Viper "Black Mamba" Generation 3 16GB (2x8GB)
Seasonic G series 550w '80 Plus Gold' Modular Power Supply
When everything is plugged in I can see a set of green LED lights on the graphics card.
I have tried all 3 PCI Express slots, no difference.
Removed all Hard drives / DVD drive, 1 stick of RAM, and any connected via USB, still no difference.
Is there anything else you guys think I should be trying? I know this graphics card requires more power than my current ATI 5850 but I am sure 500W is enough from the Seasonic PSU

I am back to using my old graphics card for the time being which is working fine.
Is it time to contact OCUK and get a replacement?