Fan Runs Continuously with 98% CPU Idle

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Level 1

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Fan Runs Continuously with 98% CPU Idle

Old problem, that Apple has closed on most metal laptop models, but is still a serious problem. I use this for live stage performance (or had planned to), and a fan noise like this will never allow that to take place. Has anyone really solved this? The machine is COLD. It is doing NOTHING. The FAN will NOT stop. Activity Monitor shows CPU 98% Idle. No peripherals attached. Battery or AC.

MBP Late 2008, Mac OS X (10.5.5)

Posted on Dec 10, 2008 4:58 PM

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Answer 1

LukeD

Level 4

3,153 points

Dec 10, 2008 5:00 PM in response to rnewcomb

There has been some good advice discussed in this thread.

http://discussions.apple.com/message.jspa?messageID=8591161#8591161

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Answer 2

rnewcomb Author

Level 1

0 points

Dec 10, 2008 5:36 PM in response to LukeD

The SMC Reset has chilled the fans (for about 5 minutes now...which is the longest they have been quiet since I bought the machine 4-5 weeks ago!) The Fan Control utility doesn't seem to make any sense, as pointed out in the thread you referred me to - only there to increase fan speed, not decrease it. So, I will leave this as 'unanswered' until a few days of quiet fan operation should bless me.

Thanks for the leads.

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Answer 3

rnewcomb Author

Level 1

0 points

Dec 23, 2008 4:41 PM in response to rnewcomb

Nope. This is a temporary fix, lasting about 24 hours. This is a design flaw.

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Answer 4

S.U.

Level 6

9,601 points

Dec 23, 2008 6:08 PM in response to rnewcomb

Did you ever try running the extended version of the Apple Hardware Test? A faulty or unplugged thermal sensor could cause the fans to run all out by default.

Good luck!

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