I have a Sager laptop that I've had for over 5 years. In the last week it has started turning itself off unexpectedly. You'll just be doing whatever and it suddenly turns off. Last night I started it in BIOS mode and just left it running, and 15 minutes later it turned itself off. I'm thinking something is wrong hardware wise, but I don't know what it is or how to go about finding out - or even if it's worth the effort. Is the thing dead?