[Maharaja]

I needed my G5 burning my DVD while i went to bed last night, so i changed the sleep setting for the computer to "Never" and only let the display to sleep.

When i woke up (after 7-8 hours), i was shocled to find my G5 Fans were spinning insanely fast and ultra loud (far far far much louder than usual)...it sounded like a vacuum cleaner billowing wind. I couldnt wake up the screen nor the computer. I had to hit the power button and reboot.

Has anyone experience this? Is the hardware malfunction?

My setup is Panther G5 Dual with 1G RAM - no added ram. My G5 is under my desk.

[reader50]

My guess would be that the G5 locked up overnight. When the OS stops responding, the system is designed to run the fans at maximum for safety.

[Maharaja]

Thanks for your reply. That sound logical...can anyone confirm on this? I'm very new to Apple/OS X. I was a PC user for a very long time. I dont want to call the tech ppl just yet and later found out its "normal"...

[Boochie]

You might try looking at the system log file (/var/log/system.log) to see if there are any messages in there indicating what happened in the middle of the night. Also check the system console, which you can bring up from the icon in the Utilities folder.

[kg109]

I just experienced that about 5 minutes ago as a matter of fact, and was about to post the exact same subject.

I just bought the machine a couple weeks ago (DP 1.8); and have had the problem happen twice. The first time it happened immediately after turning the machine on. The fans instantly started cranking up like an airplane, sounding like the tower was getting ready for lift-off. I was forced to do a hard re-start, and it had been fine until just now. I have been working, and took a break. While I was sitting near the computer, it went through the normal procedure of jumping to the screen saver, then it jumped into sleep mode. Then the fans began to kick into high gear, and it would not come out of sleep.

What the ...? I installed the firmware update last week; it was after that install that I experienced this problem (but 'not totally sure if that is the cause of the problem).

I've been watching this forum for a month or longer, and never noticed this problem until now - anyone else experience this!!??

[Agent69]

I read a thing at MacFixIt about the fan noise after sleep. One person reported that resetting the PMU fixed the problem.

[CambAngst]

I had a fan-acceleration-on-sleep problem. Traced it to a USB SD Media reader. Now I only plug the SD reader in when I'm using it. An inelegant solution, to be sure, but it gets the job done.