BlizzardPPC with noisy fan

[orange]

have you tried applying little lubricating oil to original fan? that's what I did with mine (just a drop) and its quiet now. its a temporar solution though, oil won't last long in there.
I think some people removed fan and even the heatsink and put one smaller just on PPC chip. (see album here)
but its not recommended because other chips need cooling besides the CPU. thats why it might be wise to keep the original fan (you can't get air through heatsink to cool all chips without punching holes).

[orange]

I managed to put some oil without removing anything! IIRC, I used a small 'tube' from Cotton_swab or "Q-Tip" after removing the cotton. you only need a tiny amount of oil. but you should be very very careful because it might be conductive and in some other ways bad for PCB. (slowly spin the fan few times manually)