I just recieved my HD6970 to replace a HD4870. After installation and computer start up....no signal to the monitor. The fans on the card spin...green lights come on, but no signal to my monitor. The monitor light changes to blue... then back to orange and the message 'no signal'. I have both the 6pin and 8pin power connectors attached, I have used both of the DVI connectors on card, I have removed card and reinstalled, I have tried another monitor...and nothing works. I put my 4870 back in...all is perfect. My PSU is new..Antec 25 650w ATX12v V2.3 Bronze. Intel DX58SO and current bios. I7-960 processor. 8g Corsair XMS3. Windows 7 SP1 64bit. Gateway HD2401 24" monitor DVI. I tried a friends HD 6770 and it works fine. Anybody have any suggestions?