Graphics card problem - need help please

[havocas]

Dear All,

I have an old system I know it, but it does everything I need it to do nowadays.

Recently my graphics card has not been working. The graphics card is a Asus 6850 (an old one). A link to the details of the card can be found below:

https://www.asus.com/Graphics-Cards/EAH6850_DC2DIS1GD5/

The system boots up fine, begins to load Windows as we would expect to. However, ever since I installed the new AMD drivers, my screen just goes black at the "Windows Loading" screen. As I say it boots all fine then just when the desktop is about to show it goes black. Machine is still on, but I cannot do anything on screen.

My system is a AMD Phenom 2 X 4 and a Gigabyte motherboard that has served my very well over the years.

I have tried the following:

• Uninstalled the drivers using the windows driver - system works fine
  
• Used the on-board graphics card - system works fine
  
• Installed a Nvidia card in my computer using latest drivers from their website - systems works fine
  
• Re-installed above graphics card in my computer - black screen as above
  
• Used older AMD drivers from their website - black screen as above
  
• Used older ASUS drivers from their website - black screen as above
  
• Used HDMI, DVI and VGA connections - black screen as above
  
• Formatted my computer with a fresh Windows 7 installation - black screen as above

I am pretty sure I have isolated the problem to the AMD graphics card as the Nvidia card works fine in my setup with the latest drivers. The only other check I can perform is put my AMD card in another computer and check if it works there.

You're all very likely more knowledgeable then me in this so your thoughts are welcome.

Thanks very much