There is a lot of talk on this site about how to buy aftermarket fans and passive cooling systems on towers, etc. What about us notebook users? I have a 12" Apple PowerBook with a fan that I'd love to silence. Are there any low-noise replacement fans that I could put in the PowerBook?

Every notebook PC is different. You'd have to open it up and take measurements of the existing fan and try to find a suitable replacement with the same physical dimensions.

I'd recommend you contact Dorothy Bradbury for silent fans of all sizes. She might be able to help you with very unusual sized fans as well.

Those fans are attached to a propietary cpu cooler with heatpipes, and you have to get the original part from the manufacturer. Damned laptops!. I have a noisy beast, an HP omnibook XE4500 that has an anoying fan that drives me mad, and seems there is no fix.

Regards.

Of course there's a fix, a fix that's bloody trivial if you have

a window in which to remove your HSF, eye protection, some air tools with hardened metal drills, a few suitable replacement fans, and perhaps a spare Zalman VGA heatpipe cooler.

There are probably alternate prime trivial methods, from testing the fan electrical performance and responding with the appropriate ultrasonic cleaning (in distilled water, machining detergent optional,) line filtering (2 uF at the laptop end mayhap), go-lucky electronics countermigration treatment, aerosol-drop oiling (as not to kill it with a whole drop of oil on first try), and adapting new and promising spares to your old cooling solution's profile.

Myself, I'd love to just replace the stepping of the CPU with a better one, but I don't know how (and electronics modules are past my casual dentistry.) Less heat in the first place, that way.