I recently purchased an XFX Radeon 5770 1GB card. Once I put it in my system the video will not post on any screen through any port. I'm using an XFX nForce 680i LT SLI motherboard, my friend is using an e-VGA nForce 680i SLI motherboard. All other specs such as RAM, PSU, CPU, and even Heat sink are nearly identical.
The video card posts immediately in his system but doesn't post at all in my system. I tried a BIOS update, and even though it shows successful, after reboot it still says version 6 instead of the new version 8. My motherboard works with every other card I've tried in it. XFX tech support is painfully slow to respond and only gives me responses like: "Did you connect the 6-pin power adapter?" I'm not a total idiot so they aren't being helpful, plus in my question to them, I specifically told them I tried both 6-pins from my PSU as well as the provided 2 4-pin to 1 6-pin adapter that came with the card. This is driving me insane and it's no longer a viable option to replace my motherboard since the Core 2 quads are now out of date, DDR 2 is out of date, and most motherboards today don't support those components.
Does you XFX mobo have a on board graphics chip? My 5770 wouldn't boot for the first time with it in, i had to take it out and make my mobo use the onboard one. I put it back in once i got drivers for it
Sorry for the delay in responding to this on here, and thanks for all of the responses. I did contact XFX several times and got laughable responses back from the initial tech that was assisting me. Eventually they transferred me to someone who knew what they were talking about and apparently my BFG800w powersupply wasn't firing the 12v rail that powered the video card fast enough at system boot up to activate the card. He suggested restarting the system multiple times until it came on, and if it did eventually come on(which took about 30 tries btw) that it's most likely the power supply. I swapped to an Enermax Liberty 650w my friend had laying around, it worked immediately. Unfortunately XFX took so long getting back to me that prior to this I had already acquired another motherboard which didn't help. Luckily I exchanged it back for a working power supply.
On a side note, I ended up going into Best Buy to see if they had any compatible motherboards in stock. I ended up getting into a discussion with one of their "geek squad" techs. She adamantly insisted that any ATI card will not work on a motherboard that uses nVidia nForce lol. She also got frustrated speaking about it, cussed, and turned her back to me after saying I needed to buy an nVidia card or ATI motherboard LOL! They are never helpful, but always great for a good laugh.