hhmm. Is it your video card thats failing i wonder or your monitor? When you say your monitor "shuts off" does it go into standby, does it turn off, or does it just go black.
Try booting up in safe mode. If it works you can isolate the problem as your video drivers. To get into safe mode, start pressing the F8 key after POST and the windows advanced menu should pop-up. If you start pressing it too soon a "keyboard error" will pop-up and youll have to reset and try again.
Tell us how you go