Hi there. I got a hand me down Powerbook G4. It's in great condition with a new HDD. It has Leopard installed. My question is, does the fan turn on all the time? I also know that it has 2 fans, left and a right. When I checked my iStat pro widget, it only showed the right one working. Is that normal to have 1 side working, while the other shows zero rpm? Thank-you!