The machine is 18 months old, has anew battery and never had any problem with it. While using it this morning the machine just died. It restarted again with no ill effects, bar the clock resetting. However, thirty minutes later the same thing happened. This time, grey vertical lines preceded the shutdown. Now, the machine will start up normally, approximately one in three times only to shut down after one or two minutes. The rest of the time, the fans spin up to full speed while the screen stays blank. And help would be much appreciated. Wasn't sure in which section to post this, so sorry for the duplicate.