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Powermac G5 Fans go full speed

I have a Powermac G5 here with all the fans running non stop. The Mac works fine and the temps look ok.

things I have tried with no success :
update to 10.4.7
reset nvram
reset Pram
reset smu/pmu
Ran ASD with no errors
Thermal calibration (failed, failed to read fan speed).

Tried to run it without the AJA card just for kicks.
Swapping the clear panel. Tried different fans.

I am trying to try and test everything before I report it through GSX. I would like to find out what the exact problem is so I can order the part through GSX. The G5 is still under warranty.

Powermac G5 (dual G5), Mac OS X (10.4.6)

Posted on Jun 30, 2006 1:12 PM

Reply
32 replies

Jul 5, 2006 8:23 PM in response to Mac Support Guy

Are they going full speed all the time or once and ahwile? Mine do this intermitently and I have had mine into the shop for repair 5 times. Mostly because I'll be working on a project and the program just stops without warning. Other times I'll go over to the computer and the fans are running full blast in the sleep mode and there isn't anyway to stop them other than shutting it down by force. I've had the main board exchanged (warranty) then they replaced the processors ( Dual 1.8 ghz) and multiple times in for diagnostic checks.
I have a powerbook G4 with only 512 mg of ram that runs circles around this G5 power mac with 2 gig of ram.

Jul 6, 2006 3:00 AM in response to Waterskier

You could try an SMU/PMU(as appropriate) reset

http://docs.info.apple.com/article.html?artnum=300341

Using the combo updater seems to cause fewer problems

http://www.apple.com/support/downloads/macosxupdate1047comboppc.html

Hardware Monitor may still be able to show the fan names and speeds

http://bresink.com/osx/HardwareMonitor.html

Waterskier - I know these things may have been tried by other posters in this thread - but sometimes the simple things work. Cannot simulate the problem as this ancient DP2 is fine with 10.4.7

Jul 7, 2006 10:23 AM in response to Mac Support Guy

My fans run constantly ( at least to the naked eye), but at a very quiet speed.
When I really engage the whole thing (DVD render) you can hear them gear up.
I think that by running my energy saver option setting at "highest" for the CPU
it keeps iit cooler in general and the fans run quiter but more of the time instead of ramping up and down all the time to try to conserve energy.

Jul 10, 2006 2:57 PM in response to Mac Support Guy

I've started having the same problem. It's driving me insane. The fans will stop momentarily if I quit whatever app I'm in (such as the DVD player), but then they just fire up again. The computer won't just go to sleep either; it will run all night with those fans roaring away, even if there's no activity going on.

One other possible solution I saw was to try unplugging the machine, wait a little bit, and plug it back in again (this one was for if you'd removed the plastic fan cover, but maybe it would help in other situations too (?). Haven't tried it yet.

Jul 10, 2006 10:18 PM in response to Mac Support Guy

I recently got the same problem (some time after I upgraded to 10.4.7). After a cold start the fans go full speed. When I then restart via Apple-Menu, the fans start to behave normally again (sometimes I need more than on restart).

So far I tried the SMU reset. On the next startup it seemed to have fixed the problem, but on the second startup, I got the hairblower-effect again ...

Any ideas?

Jul 10, 2006 11:43 PM in response to Mac Support Guy

This fanproblem is an older issue.

It first popped up with 10.3.8 version, but was fixed with 10.3.9.

Than, it popped again with 10.4.3 update and isn't fixed untill now.

In all these cases, the main fans start running full speed for no reason at all, often in Safari or, surely, in Photoshop - no, not for severe processor work.

Nothing helps.
( Please, do not mention the Energy settings. )

It obviously is a software problem, cause I have 10.4.2 installed on my main drive, with no fan problems, and 10.4.7 installed on my other, back up, internal HD, with the fan issue.

Worst of all, Apple don't seems to hear it or be concerned about it ...
May be because only a minor group suffers under this problem.



G5 2x2 Mac OS X (10.4.2)

G5 2x2 Mac OS X (10.3.8)

Jul 11, 2006 12:04 AM in response to DirtyMay

You know, I am going to go out on a limb here and say that I have stumbled upon a fix for my noisy fans. Whether this is unique to my situation or not I have no idea, but it works every time.

Every time I have to restart my machine, my fans go nuts. It's almost like they are on a timer. If you open Temperature Monitor you can watch the temp of my machine steadily climb by .3ºF. Once it hits 150ºF, boom, fans. They stay on for a moment and then the temperature slowly goes back down. Wash, rinse, repeat.

At any rate, I had tried all the resetting the PMU, the SMU, zapping PRAM, etc., etc. Then I decided to try something. I reinstalled the latest OS (for me I am running the 10.4.6 PPC Combined in this case) and all was well. It's a bit of a pain to have to do every single time I restart (a process which I have nearly cut out of the routine of this machine), but it gets the job done none the less. Every time I reinstall the OS, the fans go back to their normal behavior. This leads me to believe that the fan problem may be as simple as possibly a corrupt preference file or package receipt somewhere (??).

Powermac G5 Fans go full speed

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