View Full Version : Replacing the CPU fan in a quicksilver G4?

May 20, 2005, 12:59 PM
Hey All

I just got back from school and my mom's computer is making this loud, obnoxious noise. Its a 733Mhz Quicksilver G4, stock except for a BTO ZIP drive and an extra 512MB DIMM. Listening to the computer I decided that the noise was coming from the fan mounted next to the CPU heatsink. When we pulled the computer out of its shelf on her work desk, I found that the (intake?) holes were thoroughly clogged with dust. We vaccuumed that stuff out and started up the computer but its still making the noise.

My guess is that the fan is thoroughly shot. It turns itself on and and off intermittently. I touched the CPU heatsink to see if it was overheating. (The OS doesn't report temperature anywhere, does it??) It was hot to the touch, such that I could put my hand on it for a few seconds but I could tell that it was too hot to keep my hand on for much longer. Is this too hot?

I'm telling my mom to take it easy until we replace the fan. Does anybody know what part number it is? It looks difficult to get to because its mounting screws are behind the heatsink. Should we take this to a pro or can i DIY? I'm not faint-hearted with electronics and I'd prefer to save the money if possible. Apple support web site didn't offer much...If I don't get any ideas I'll probably just pull the fan out and go to the store and find the nearest spec'ed fan to it.


May 20, 2005, 01:12 PM
download and run temprature monitor, then post your results

May 20, 2005, 01:15 PM
Used to have the same QS model; it's a noisy fan all the time. It was easy to replace the cpu fan. I don't have the computer anymore or I'd open it up and describe how to do it, sorry. But I think it was as simple as removing the screws and unplugging the power.

About the heat - the normal temperature apps like ThermografX don't report a temp, but it will shut down suddenly if it gets too hot.

May 20, 2005, 01:17 PM
In fact, you ought to just convince your mom to get a CPU upgrade - if you get an OWC cpu it will have it's own new fan that is quieter and much smaller.

May 23, 2005, 06:54 PM
Thanks for the tips everybody. Today I opened up her mac and popped out the fan. It looked complicated at first because it has mounting screws that are hidden behind the heatsink, but then I realized that those screws just mount the fan to its rubber housing...The real mounting screws are accessible from the back panel on either side of the intake vent. So it was real easy and fortunately Apple uses a standard fan which was easily replaced for $20 at the local electronics store. The new fan uses less power (.11 amps at 12V instead of .22), but moves a good amount of air and is quieter than the old, broken one. Case closed!