Strange think happened last weekend. I have a 2 year old laptop, used mostly by my daughter, that went completely brain-dead. No power light (when power cord plugged-in) and the restart button did nothing. I took out the battery and put it back in - and it restarted!! I'm guessing there must be an internal circuit-breaker or surge-protector that tripped, and was reset by taking out the battery.
Anyway, it happened again a few hours later. My daughter said that both times she just moved the mouse (corded) and the screen went black. The mouse cord by the USB plug does appear to be 'pinched' a bit. I gave her a different mouse and the laptop has been fine ever since.
Has anyone heard of such a problem? I hope this helps if anyone else encounters this type of situation.