1. When you first power up the machine, does it appear the display is "turned on" in any way? Meaning, if you power it up in a completely darkened room, do you see any light whatsoever from the display? If not, this may mean the display is dead.
2. Try selected DEFAULT video drivers at boot time. This has solved a number of video issues for me. If you then have video, then you know it is driver related.