i got Visiontek hd6950 2gb and i tryed to flash it as everyone else did but unfortunatly i failed!! there was no erorrs while flashing just when i rebot pc there was no signal from gpu any more!! now i wanted to flash it back using integrated gpu on motherboard but when 6950 is in slot i dont get signal from integrated gpu either!! do i need to have pci-e card to flash it back or what??