Hi all. My one and a half year old 15" Powerbook G4 aluminum last night started to make a loud whirring sound, and since then it's happened again 4 times. Being somewhat familiar with the innards, I'm 98% sure it's the right fan, roughly under the "eject" button. It sounds like it's ready to kick the bucket, and if I press the eject button or any in that area, the fan speed audibly slows down. So is this thing dying? What would cause it to all of the sudden start working so loudly? (and it's loud alright). I'm in the northeast, where we're experiencing our first true heat wave of the year, but this never happened last summer (the first summer the laptop has been in existence). I read somewhere else during a frantic google search that it might be hard drive related, and that putting it in the fridge took care of the problem(!). But my hard drive is newly installed as of a month ago, although the drive itself is older than that, not sure how old. Should I be worried about the well-being of the rest of the computer's components, i.e. are they in danger of overheating/being seriously damaged? Should I stop using the computer altogether until the fan is replaced, or just stay away from programs that cause the machine to work hard, such as Google Earth? And lastly, how much will it cost for a new one of these?