Optical drive Fan noise

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Optical drive Fan noise

For the last week or so, the optical drive fan in my iMac would suddenly rev up to 5000 rpm , ( thus making a fairly loud noise ) , after "waking up" from an "energy safer" induced computer/display sleep of 15 minutes. If I don't put the computer/display to sleep, the optical fan would just stay at 800 rpm and no undue noise.

To get rid of the optical drive fan noise, I have to shut down the computer for 15 minutes and restart it.

What is the reason and how can I fix it?

Thanks.

iMac DC-20", 2G, 256 Vram; Mac mini, MBP 15", 2.2 Ghz Leopard 10.5.4, Mac OS X (10.5.2)

Posted on Jul 16, 2008 5:39 PM

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Answer 1

Jul 19, 2008 11:13 PM in response to JE3

Is your Optical Drive getting used a great deal? That is, getting really hot?

If you want to go back to factory default you could try resetting your SMC...
http://docs.info.apple.com/article.html?artnum=303446

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Answer 2

JE3 Author

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Jul 20, 2008 2:58 PM in response to polarbear79

no. The optical drive is hardly used at all, less than a few minutes per week.

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Answer 3

Jul 21, 2008 1:46 AM in response to JE3

What are you using to check the fan speeds?

George

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Answer 4

JE3 Author

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Jul 21, 2008 3:57 PM in response to George Peters

iStatPro

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Answer 5

Jul 21, 2008 4:27 PM in response to JE3

Try resetting the SMC as PB suggested. One possibility is the ODD temperature sensor may be failing. An inaccurate temperature reading could cause the fan to speed up unnecessarily. I would monitor the ODD temperature and see if it changes in correlation to the fan speed. A zero or blank reading would indicate no feedback from the sensor. Also try running Apple Hardware Test. Insert the original gray iMac install disk, restart and hold down the "d" key. Run the Extended test.

George

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Answer 6

JE3 Author

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Aug 13, 2008 6:36 PM in response to George Peters

Hello George,

Tried resetting the SMC , etc. but without success. The ODD temperature has always been stable and not above the default.

Then, I just adjusted the fan speed from minimum of 800 rpm to 1000 rpm and it seems to have done the trick. For the last few days, there has been no further fan noise when computer wakes up from sleep after 15 minutes or more.

Thanks .

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