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Level 1

20 points

Mac Freezes and fan goes into overdrive!

Help! First of all, sorry for the length of this... (ahem...)

I have a *Dual 2.3 GHz G5* running OSX ( 10.4.10) that has started to freeze up to 4 times in a working day (most noticably when having iTunes running - but not always) and then the fans start to run fast (and noisy!) and doesn't stop until you 'force' shutdown using the button on the front of the Mac.

Software update is... well, up to date. The Mac has loads of room round it - so shouldn't be overheating (would the system freeze if it overheated or do the fans cut-in to stop overheating?).

There seems to be no rhyme or reason to it as this also happens when iTunes isn't open (i.e. I sometimes back-up files overnight and this problem will occure sometime in the early hours - but again, not always).

I have run the Hardware test from the DVD that came with the Mac - with no errors/problems found.
When I run Disk Permissions from same DVD, it will invariably come up with differing permissions in iTunes, which it says it fixes.

The finder will also 'crash' intermittently - any folders open on the desktop will all close, but no open applications/documents are affected (this can be really annoying when hunting down a file in a folder buried deep within other folders - you eventually find the one you need then everything disappears and you have to start again!!)

*Can anyone shed any light on what could be wrong and how I can fix it!?*

*Many thanks in advance,*

Col

Dual 2.3 GHz G5, Mac OS X (10.4.10)

Posted on Nov 2, 2007 9:46 AM

34 replies

glacon

Level 1

0 points

Jun 2, 2008 6:40 AM in response to Whitedogpoo

I have a quad core G5, just under two years old. I am not having the problem where the computer falls into sleep mode, it won't wake up and the fans go into jet-engine mode. I did not have this problem before I installed 10.5.3, the most recent leopard update. Anyone figured this out yet?

adsfushi72

Level 4

1,115 points

Jun 2, 2008 3:05 PM in response to DoubleG1

If you haven't tried a PMU reset, do that. If that doesn't work, see below:
The below procedure solved the problem for me. I'd be interested to hear if it works for you.
1. Open System Preferences and go to the "Energy Saver" preference pane.
2. Find out how long your computer (not your display) waits before going to sleep. Remember this number.
3. Open Terminal. You can find it in the Utilities folder.
4. Enter the following command and press Return:
sudo pmset -a disksleep n
where n is a whole number greater than 0 and less than the number from Step 2.
5. If you are the administrator, enter your password. If you're not the administrator, enter an administrator password.
6. Press Return.

Finally, remember not to put your computer to sleep yourself. Instead, you can start the screensaver, put the display to sleep, or just let the computer fall asleep on its own.

Although I don't know the cause of the problem, the above procedure solved the problem for me.
Good luck!

socokid

Level 4

3,151 points

Jun 3, 2008 7:43 AM in response to Whitedogpoo

Have any of you tried resetting the PMU by pressing the reset button on the logic board to see if that helps?

Jul 2, 2008 9:33 AM in response to socokid

I have reset the PMU, Archived and reinstalled the os, cleaned out all the dust inside the machine....... on and on and on and yet still I get random freezes and jet plane fans. My G5 is currently at Apple and has been there since last Saturday. I took it in for repair last Thursday, they recalibrated the processors and said that fixed it, I picked it up Friday night and the same problem started first thing in the morning. Saturday, the the machine went back to Apple. I am still waiting for them to figure out what is causing this problem. I am not happy with how long this is taking.

Mac Freezes and fan goes into overdrive!