Toshiba laptop goes black after windows loads

Hi. My Toshiba satellite turns to a black screen directly after the windows load-up page finishes. The same thing happens if I try to start it in safe mode. It was just fine until I pressed and held the power button for a moment in an effort to force it to reboot in safe mode. But now there is no log in screen, just a curser (not blinking). the only way to shut it down is to hold down the power putton for a moment or take out the battery and power cord.

Any idea why the screen stays balck? I suspect it is not the screen as the windows boot up screen does it's colorfull window logo just fine...

PLZ help if you can.

THX,
Tony