What I was getting at was that ~when you switched it on after the pc had booted ,then was it a blank screen or not? It could be a lack of power problem at start-up. Check monitor cable is pushed far in.
When you installed the new video drivers did you uninstall the old ones.Best to do this.Have you got an old PCI video card to compare progress. In the bios ~is the card set to 128? See what happens when you select Optimised Settings in Bios.