My laptop (a HP dv6140us) crashes to a screen with a bit of the screen
tiled over the entire screen in diagonal lines at random moments (even
when I don't touch anything). I have to then hard shut down the
laptop. It also fails occassionaly to wake from sleep and result in a
black screen. Other times it seems when going to sleep to go into a
high power mode (where it's fan runs at full speed and gets very hot).
Any ideas?