View Full Version : Power Mac G5 - Driver Fan at Constant High Speed

Feb 13, 2010, 08:38 PM
Hey guys,
Running... Dual 2ghz Power PC G5 with Leopard 10.5.8

Recently had it in for a repair, not with Apple (that expired a longggg time ago) because it would only turn on intermittently. They fixed this problem, citing bad components and also replaced the broken optical drive. However when they gave it back to me it was incredibly loud, they stated that they had to reconnect a fan and that was probably what caused the power problem in the first place. I'm pretty sure though that I had disconnected it unwittingly about a week after the power problem started when I opened it up to change the battery... believing that may be the problem at the time.

I installed iStat and these are the stats for the fans right now...

Drive Bay - 4000rpm
Slot - 255rpm
Backside - 204rpm

That 4000rpm doesnt change from boot up to shut down and is just a constant noise. I've tried resetting the SMU and tinkering with the energy saving options, even did a complete erase and install when I updated to Leopard, the hardware test shows no problems, and still the same level of fans.

Anyone got any thoughts on this, what might be causing it, and anything that I can do to test/fix it?

If not I guess its time for a different repair company to take a look!

Feb 16, 2010, 03:05 PM
The fan's pin/cable that controls speed may be damaged. I have a similar G5, and I do not recommend thinking you can fix any f the annoying issues it's fans have.
Good luck.

Feb 16, 2010, 03:12 PM
Simply exchange the fan with a non Apple one.
I did this on my late '05 G5 to reduce the noise of that machine.
In case of the PCI bay fan that's a 5 minute procedure.

The PCI bay uses 80x80x25mm fans IIRC. Apple uses 4 pin fans, with another pin occupation than normal PC fans though. It might take a few attempts to figure which one is right.