Hi, previously I had a 6950, but recently I have added a second 6950 (same exact card) for crossfire. But after I installed the additional video card and turned my computer on, nothing, no signal. I am sure that both cards work fine since I have tested them 1 by 1. So now I am puzzled on why this is happening.
OK you have the PCI-E power connects plugged into both cards correct? Is your monitor plugged into the top primary card? And what make/model PSU do you have? depending on the PSU it may not be able to drive 2 6950's.