pollytintop, I do think you might be right with having to replace the display, however, give this a try and see if it changes anything. Open up the battery cover (philips head) and right next to SL1 are two holes with 'screw' like things in them, these control voltage to the screens. I'm not sure which one is for the top screen, should be the furthest to the right. Grab a thin philips head screwdriver and turn the 'screw' inside there slowly, your screen might fuzz out like crazy, then turn it in the other direction. I did actually find that some people have resolved their GSOD issues :) Good Luck