Guys I really need help here! I bought a Gigabyte radeon 5770 today and it doesn't display anything! My computer boots up, I hear everything powerup but there is no display. I tried plugging in my old (Gigabyte 7600gs) graphics card and it worked just fine. I'm using a GA965p-ds3 motherboard and have 500w of power. Can anyone please, please help me out here?

That sucks. Hope that helps.

This may be a stupid question, but did you make sure that all power supply to graphics card power connectors were connected? I know I've stupidly forgotten that step before while doing maintenance on my computer.

Yes, It's powered up since the fan spins on it. 

You're getting no display? You should still be able to get into POST and boot up into safe mode. Are you sure the monitor cable is securely attached to the 5770? 

What Brand and rating is the PSU? Rest of system specs?  Also clearing the CMOS may help since adding new hardware can always confuse certain motherboards.

That's really odd, i'm not sure what to say, you should at least get some sort of graphics going through there if you plugged it into the dvi slot to your monitor, even if the resolution isn't scaled properly yet until you changed it. You should at the very least see a picture, maybe try the other dvi slot.

I'd say check the power cables. When I was installing my 5850 I wasn't getting a display out of it and the fan was going but super loud. I plugged an additional power cable into the card and it started working.

Sorry I didn't update here, I just switched out my 450w power supply for a 550w and now it works perfectly.

have fun with your new card now that it works