G5 Fan issues

clubagreenie · 04-11-2007, 08:09 AM

I am having issues with keeping my unit alive, it seems when CPU temps (according to IStat) reach around 55degC it shuts itelf down. The fans cannot be heard running, though when started up into single user mode they run flat out as expected. So they are physically fine. Is there a hardware controller for them or is it software only? I've been through steps outlined here

http://www.mactalk.com.au/forums/showthread.php?t=29109

to no avail, even rebooting from SUM turned the fans off. Turning up the processor performance from auto to highest has made it more tollerant so far (reached 63 degC)

Only refs in console logs to temp related issues is

second level name cpu_temp in kern.cpu_temp is invalid

Repeated twice.

Apple have been no use (as expected) with the bonus of even though they have physically seen the machine for some reason they don't (won't?) recognise the serial no. Techs at local shop won't book in beause apparently they can't get supplied w/out numbers.

tlarkin · 04-11-2007, 10:06 AM

Here is what I do when encountering this problem, after making sure I have all software/firmware updates ran:

1) reset SMU http://docs.info.apple.com/article.html?artnum=300341

2) Reset open firmware by holding down cmd + opt + O + F at start up and running this:

Code:

reset-nvram
reset-all

3) reseat the fans

4) Reseat the processors

5) Try with only one processor in the unit (if it is a dual) and swap it out each time.

From these 5 steps you should try running the machine after completing each one. If you get all the way down to running with one processor you may have a hardware issue.

**EDIT** Oh and if you do get down to the running one processor troubleshooting step, you must have one processor in slot 0, ie the top slot. You leave the bottom one empty. This will narrow down if you have a bad processor or logic board.

clubagreenie · 04-15-2007, 04:15 AM

Thanks,

Had previously tried the SMU/PMU etc reset, hadn't known of the openfirmware thingy. Did it all and took 2 or 3 more shutdowns and from another post I also bumped up the processor performance to high and it seems to be ok now.

Fans are definately running, though haven't reached flat out by any means. They are audible and IStat shows increased RPM's.

04-11-2007, 08:09 AM	#1
clubagreenie Prospect Join Date: Apr 2007 Location: Sydney Posts: 3	G5 Fan issues I am having issues with keeping my unit alive, it seems when CPU temps (according to IStat) reach around 55degC it shuts itelf down. The fans cannot be heard running, though when started up into single user mode they run flat out as expected. So they are physically fine. Is there a hardware controller for them or is it software only? I've been through steps outlined here http://www.mactalk.com.au/forums/showthread.php?t=29109 to no avail, even rebooting from SUM turned the fans off. Turning up the processor performance from auto to highest has made it more tollerant so far (reached 63 degC) Only refs in console logs to temp related issues is second level name cpu_temp in kern.cpu_temp is invalid Repeated twice. Apple have been no use (as expected) with the bonus of even though they have physically seen the machine for some reason they don't (won't?) recognise the serial no. Techs at local shop won't book in beause apparently they can't get supplied w/out numbers.

04-11-2007, 10:06 AM	#2
tlarkin League Commissioner Join Date: Mar 2003 Location: Kansas City Posts: 11,347	Here is what I do when encountering this problem, after making sure I have all software/firmware updates ran: 1) reset SMU http://docs.info.apple.com/article.html?artnum=300341 2) Reset open firmware by holding down cmd + opt + O + F at start up and running this: Code: reset-nvram reset-all 3) reseat the fans 4) Reseat the processors 5) Try with only one processor in the unit (if it is a dual) and swap it out each time. From these 5 steps you should try running the machine after completing each one. If you get all the way down to running with one processor you may have a hardware issue. EDIT Oh and if you do get down to the running one processor troubleshooting step, you must have one processor in slot 0, ie the top slot. You leave the bottom one empty. This will narrow down if you have a bad processor or logic board.

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04-15-2007, 04:15 AM	#3
clubagreenie Prospect Join Date: Apr 2007 Location: Sydney Posts: 3	Thanks, Had previously tried the SMU/PMU etc reset, hadn't known of the openfirmware thingy. Did it all and took 2 or 3 more shutdowns and from another post I also bumped up the processor performance to high and it seems to be ok now. Fans are definately running, though haven't reached flat out by any means. They are audible and IStat shows increased RPM's.