My Powerbook G4 is being sent to Applecare tomorrow to fix the screen problem. It also had a problem in that the fan was on all of the time and temperature readout of the graphics card was always 100 degrees C. I let them know about this at the same time. I've checked on it again today and the graphics card temperature is now showing as 'disconnected'. Should I notify Applecare before I send it to them? Has anyone else had this problem before and what will the likely solution be?