Powerbook Hard Disks.
If you find that your Powerbook sounds like a distant helicopter when you carry it around, replace your hard disk… now before you loose it! Apparently the Toshiba 60G disks bearings in G4’s fail with too much heat. I thought mine was just the fan…. until it sounded more like a Chinook overhead. http://www.raf.mod.uk/equipment/chinook.html