I guess tightening a few screws didn't do much.  My laptop shuts itself down more than ever!  Sometimes it's constant - just as you start it back up, it shuts down again.  Other times, I might get to type a couple of lines, and then it "dies."  It always restarts - sometimes all on its own - but it is very annoying when it shuts down with no warning.  I'll have to catch time online when I can, and maybe clean the house (for a change) when I can't.