I would look back on the thread, but it is a tad big
Have you had this problem from the off regards this PC ?
I had a new LDC on a new build PC, that somtimes fired up and somtimes didn't. I did not get BSOD, the PC did not crash, it just left you with a blank screen, I take it you have tried other LCD or even CRT monitors on the PC?
Brian is right, if all else has been tried, it is time for a reformat and reinstall. If only to eliminate any doubt that it is a PC problem, as against a monitor problem.