Got the Q6600 and board from Fry's. Install everything, using stock fan. Plug it in and let 'er rip. Fan spins, drive opens and closes, LED's on the case glow, and on the monitor..... nothing. Just says "Invalid sync" like it used to when I turned it on with the computer off. D'oh!
Question 1: Does your motherboard have on-board video?
Question 2: Does your system have a stand-alone video card?
If the answer to question one is "Yes" and question 2 is "No", make sure your on-board video is enabled in the BIOS setup.
If the answer to question 1 is "Yes" and question 2 is also "Yes", then disable the on-board video in BIOS. (There are some situations where you would leave it enabled, however, but this is not one of them.)
If the answer to question 1 is "No" and question 2 is "Yes", then you might try reseating the video card. Whether it is in an AGP slot or a PCIe slot, they can sometimes be inserted a little off and not work. When that happens, it usually does not harm the video card. Just reseat it, being careful in how you put it in its slot, and try again.
If the answer to question 1 is "No" and question 2 is "Yes", and the steps in the above paragraph don't work, then you may have a toasted video card.