I was given a 1.67 GHz PowerBook G4 that runs on the hot side and also has a loose hinge on the right side. I am going to repaste the CPU and in the process also remove the display and tighten the hinge. When taking apart my 1.5 GHz PB I realized the GPU uses a type of thermal compound I have never seen. It looks like a pad's thickness but in the shape of an X. I left it alone and reassembled the Mac without issues with GPU heat. That being said, this one always ran hotter than the 1.5 no matter what. I know the paste and pad is on its way out. My question is, what do I put on the GPU? For the CPU I am using Arctic Silver Ceramique 2.