I typically have the same issue. Mine is a Toshiba Satellite. I used to keep unhooking it and then rehooking the power cable, only for the screen to be black. For some reason, hitting the PLAY button (my laptop has the volume, play/pause, rewind, fast forward touch "buttons" right next to the power button) fixed it. It's almost like the screen is turning off and needs to be "played" when I start the laptop. It doesn't happen a lot, but it would happen every blue moon, so now on the rare occasion that it happens, I just hit the PLAY "button" and once that "button" (it's not really a button, but you know) lights up white, the screen comes on and the laptop boots normally.