Thursday, January 24, 2013

PowerMac G5: CPU fan "repair"

One day I switched my PowerMac G5 (Late 2005) on and it was producing lot more noise than normally. After opening the case, I found out that one of the CPU exhaust fans was spinning on full speed. First I tried restart, SMU reset, PRAM reset but nothing changed, so I realized it must be HW problem. I asked google and found some interisting pics:
6-pin connector for both CPU exhaust fans
First pic is from page where user Nico shows hwo to rebuild G5 to a Hackintosh. On the picture he shows how to use the original (G5) fans.
How are the two fans connected to one connector
Second one is now available only in google cache, originaly from some phorum.

First I found out which of the fans is broken (A or B according to the second pic), than I played with the wires and after many tests I finally found out that pin 6 on the mainboard wasn't working correctly.
So my solution to fix this:
As the noisy fan was B in my case, I connected its red wire (according to the second pic) which is +5V to the pin 2 (another red wire). Now I have both fans running on one +5V feed line and they are spinning normally (quietly) again.

1 comment:

  1. I have a dual fan from a PowerMac G5 and they are 12v nor 3v. It use the same 6-pin connector. Is the voltage different depending upon the G5 year model?

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