The card has been installed, with power to both power connectors; the fan runs but there is no video signal out detected from either of the DVI connectors (checked both digital and analogue on the DVI-I port), with various monitors. Checking the integrated graphics port showed that the 6850 card is not switching-out the integrated graphics during boot, but appears to be disabling it after the BIOS has handed over to the bootstrap ... the PC then reboots a few seconds later, before it has started the OS. This is not something found with any previous graphics card. We have checked the motherboard compatibility with the ASUS 6850 and as PCIe 2.0 x16 there should be no contention. The 6850 simply does not start and repeatedly trips the PC to reboot. As you stated the card to be used but functional, I am at a loss as to where to proceed next. "
BIOS flashed, there was a later version available. Still no video out on either DVI port on the 6850, but the PC no longer keeps rebooting, thank you for that! The integrated graphics port is now remaining in operation, but after the boot screen all three of my available analogue monitors (1024x768, 1280x1024 & 1920x1080) register "out of range", so I cannot see what is happening. From the beeps, I think the PC is booting-up, but this will be on a Linux partition (first in the boot list), not Windows. Returning to my previous PCIe 2.0 graphics card, everything is fine. Any other suggestions?