I've had this problem for a while now. But where to begin...
I removed my 5770 from a working case to change its cooler. When I put it back in, I got a black screen. Tried lots of things, concluded that it must have been dead from a static charge (did wear woolen slippers at the time lol, thanks Santa).
Bought a new gpu, xfx 6870. To my horror, the same problem occurred. Fan spinning, windows loading on the background and only way to get a picture was to plug the DVI to mobo (6870 was still slotted).
MEANWHILE, i received conformation that the previous card, 5770, was indeed dead.
So I decided to test the 6870 on a friends pc as well and it worked...Then i sent the motherboard to another friend, who tested it with his own gpu and psu, that also worked.
So I concluded that it must be my psu thats causing the problem. I have a modular 850W SilverStone Strider. Since it was powering my system successfully without the gpu, I figured maybe one of the 6pin sockets was damaged. I switched the cables around, tried molex to 6pin adapters and nothing. Took the gpu out for a while and in frustration tried again later. I dont quite remember what else I did exactly but IT ACTUALLY WORKED. Thats until I needed to restart, after which I got the black screen again.
A couple of million retries and messing around later, I got it working once more. Now I remember what i did prior to that (Im not sure though that it had anything to do with it starting properly). While to DVI was plugged to mobo, I ran the windows "Find and fix problems with devices" troubleshoot utility, it said "Hardware changes might not have been detected", "The troubleshooter made some changes to your system, try attempting the task you were trying to do before."
Ahaa, thats it I thought. So I plugged the Dvi from mobo to gpu but it still didnt give me picture. Powered down with the power button and turned it back on. Now thats the second time I got it working. Happily I thought the problem was gone for good. Until I needed to restart (the reason being that I used ASUS TurboEVO to apply auto overclock, again not sure if that even matters).
So whats causing this randomness, only 2 successful power ups out of ~50. Now the other things that I though of:
- Different pci slot
- While the dvi is in mobo but the card is still slotted, only the integrated intel 3000 graphic is turning up in device manager
- In bios under System Agent Configuration > Graphics configuration > Primary display is set to [Auto], can also set it to PCIe, but it switches back to Auto. That should work as well, shouldn't it?
When the dvi is plugged to the gpu, the monitor shows the "entering power save mode" icon for a sec and then powers down.
I hope this wasn't too long and confusing, any thoughts would be greatly appreciated.
Yes, uninstalled the old drivers. But the system should at least give me a picture, even if I didn't have the drivers for 6870 installed. Well anyway, Ive tried it with both, with them installed and without. No difference.