iMac Intel 27" EMC 2309 (Late 2009, Core 2 Duo 3.06 or 3.33 GHz) ID iMac10,1, EMC 2374 (Late 2009, Core i5 2.66 GHz or Core i7 2.8 GHz) ID iMac11,1

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Hard disk low frequency noise/humming

I have an iMac 27" i7 late 2009. I just replaced the internal Seagate 1Tb hard disk with a seagate barracuda 3Tb (compatible temperature sensor). Everything is working fine except for a very irritating low frequency hum from the hard disk. I tried already many things like tightening the hard disk screws (it makes the problem worse) and placing the iMac on a soft rubber pad.

Is there something I could do to dampen or mitigate the hard disk noise?

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Where did you find drives with compatible temperature sensors?





Just a thought, but you may consider loosing the screws?

( making sure they have a tiny bit of blue threadlocker of course, if not already on there), they dont need to be that tight...... in fact in my standard regular non mac PCs i only use two screws.

Also they are some silicone grommet solutions to reduce vibration, i have not done this for an imac, but thought it might give you an idea of a product to look for.

lastly, check for anything too tight, or loose that may cause it during the taking apart and putting it back together. If possible having the computer on while u track down the source of the noise.

just some thoughts, again i have not taken this approach for your specific computer.


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Hi Brian, and thanks for your tips. On an iMac it's rather difficult (but still possible) to have the computer on while accessing the Hard disk compartment. This is because the hard disk is placed right behind the LCD panel and this means disconnecting at least the v-sync cable while lifting the LCD panel to access noisy part.

I didn't notice any threadlocker traces on the hard disk screws. There are two silicone grommets per screw isolating the hard disk. Now that I am thinking, there is as well a piece of conductive foam between the outer shell of the Hard disk and the back of the aluminium shell. The foam is quite compressed so it might transmit vibration to the rest of the computer. I will try moving the foam to a different position.


Victory! I couldn't find a specific grommet but I found a type of soft rubber rings used for sealing water pipes that did the job. I placed an additional layer of isolation on one of the hard disk brackets and this did the job. :-)


Thats great, Thanx. glad i could at least offer some info in the correct direction, please accept my answer if the problem has been resolved, based on your description, seems like it should work fine barring any type of airflow restriction,


Hi Brian, Your answer helped me indeed. Considering the low pitched noise, I thought it was coming from a sub harmonic of the 7200 RPM hard disk rotation. Also when the Hard disk was going into sleep mode, the noise was disappearing making it clear that it was coming from the hard disk unit.



SUPER!!! TY !!! Added some rubber (bicycle tire repair kit) and the humming sound from 7200rpm HD is gone!


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Luca Vicini crwdns2893898:0crwdne2893898:0

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