I have a PCI express video card, eVga 9800gt, recently it stopped displaying on my moniter. The fan on my graphics card is still running so I know its not completely dead, just no display. Yet if I plug my moniter into the onboard graphics, I don't have a problem at all. I have tried to disable my onboard graphics but thats not working either. I know very little about this, so I'm lost for whats going on. What could be going on here?
I actually had the same exact problem with my Sapphire Radeon 4870 512mb. At first I didn't know what was going on. I noticed there was alot of dust in my GPU (particularly near/on the fan). I got my duster and took out most of the dust in the heatsink and on the fan, and turned on my PC and it worked out perfectly. Try taking the dust out of your GPU, that might help. If that doesn't work make sure your power connectors are properly connected because sometimes that is the problem.