My screen suddenly started jumping all over the place. It's not showing any error messages or going black. It just keeps jumping around so that it is almost impossible to read. It isn't rolling or going on or off. It just moves up and down about two inches at high speed.I notice the sreen gets less light and when i push the F 7 brightener shortcut i get a circle with an x. i would imagine this means won't work.Any idea's