The only issue was that the lines for cutting were drawn too large and we ended up with a slightly larger hole than it should have been(About a millimeter off). Also I tried one of those new-fangled liquid bearing fans. I used a 1200 RPM one, which isn't completely inaudible, but definitely less noisy than similar ones I have.
Anywho, pics or it didn't happen:
Also a side rant against Apple. First it was impossible(Yes I said impossible!) to figure out fan speed or system heat in software. Nothing was for his version of OSX(10.39 AKA: Hello Kitty) and as far I can tell there is no basic BIOS to look at. Also I couldn't find it in /proc. On the hardware side, the original CPU fan design was utterly retarded. It pushed air through a sealed up copper heatsink. This wouldn't be bad, except that the area the fan blows out is incredibly small(About 1/3 the size of a normal CPU fan). This obviously means the fan has insanely high RPMs and thus an insane amount of high pitched noise. I realize they wanted a slim form factor to look 'stylish' but did they fail to test the thing? They could easily have used multiple fans, or bigger fans on the back, but it wouldn't be Apple if it didn't suck.
Edit: To Rachel, your processor definitely should not slow down when the fan comes on. There is such a thing as variable speed processors, but those are almost exclusively used for mobile computers. I'd think it would error out if there was somehow a problem with your PSU that was draining off power from the CPU. My guess(Without knowing more) is that the fan noise is so irritating that everything just seems to be taking longer :)
Edit: A little more detail on the actual steps taken:
Modification StepsPretty simple, but definitely not for the faint of heart:
- Take off the back cover of the iMac case
- Remove the CPU heatsink cover(It has a big G5 emblazoned on the front). You should be greated with a big set of copper fins. There are some small tricky tabs that hold it in place. Also mine came completely off, but apparently some versions have to be cut off
- Find the CPU fan connector on the motherboard and unplug it, plug in your new fan and test it. But my version didn't have a CPU fan plugin(Trust me I checked and unplugged everything several times), so I forcefully removed the CPU fan(it's towards the bottom) turned on the computer really quickly, used a multimeter to check which leads were positive and negative(It had 3 wires, one is for speed sensing I think), and then cut the wires on my fan and spliced them in.
- Next I marked on the back where to cut for the fan(Directly over the heatsink) and cut it out with a Dremel
- Finally mounted the fan to the back over the hole and put everything together again