On that post mentioning the PC that was doing the black screen,
it wasn't the monitor, wasn't the video card, but it turned out to be either increasing the AGP aperture size in the CMOS from 64 to 128 or reseating the RAM. More than likely I suspect it was the RAM.
I did these adjustments both at the same time and now the display has stopped blacking out so far.
Its such a good feeling when you get lucky fixing PC annoyances.
These machines are so amazing in what they can do, but so darn sensitive to just one little thing not being exactly right.
