So...I posted something similar to this earlier, and I posted about issues with my new radeon HD 5870 card as well...but figured I'd post this issue here as it relates to my motherboard. As I described in the radeon post I made...my new HD 5870 seemed to not be working. I tried different configurations with PCI-E cables and nothing would happen...the system would power on but there would be no picture. So the last configuration I tried was a PCI-E cable straight from the Power supply and a PCI-E to molex (that at the end had two molex adapters which I plugged in).
Anyway I hit the power...the fans spun for a half second and nothing happened. Put the old GPU back in and uh-oh, nothing happened then either! I tried the PSU with the motherboard from my old system (an Abit KN8) and...it worked. So it looks like this new motherboard, which is actually a replacement after a Radeon HD 5850 I tried fried it the first time (differen story)...is fried. Is there any way I can fix this? Is it really fried? I push the power button and absolutely NOTHING happens. Yes, the PSU -is- turned on.
The wierd thing is that this is different than what happened before...before the MB wouldn't work (it wouldn't post) - but the fans on everything WOULD be spinning. Now absolutely nothing happens.
Try the old ps with your 5850 on the newer board if you haven't already. Could be your ps isn't compatable with the video card, not the board. I would also try a low end pci-e card which doesn't need any ps connections on your board before sending the board in for warranty.
My asrock x58 extreme died on me after 4 days of use. I had it working with an xfx 5850, and it was awesome til the board died. The debug led no longer shows anything on boot, no picture, i tried clearing CMOS and the cmos jumper, and no luck. Its going out for RMA this week.