iMac fan always running after SSD

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Level 1

30 points

iMac fan always running after SSD

I replaced the default Seagate 500GB HDD in my iMac 21.5" with a 250GB Samsung 840 EVO SSD this week. While I was disconnecting the old drive, I noticed that there was a thermal sensor cable, that had no space on my new SSD, so, I didn't connect it to anything. The iMac works normally, but now the fan is always running. It's not running at top speed, but its running significantly faster than it used to. I'm assuming its something related to not connecting that thermal sensor cable, but what can I do about it? It's a late 2009 21.5" iMac with 7 GB of RAM. OS X 10.10.4 Yosemite.

Thank you!

Posted on May 30, 2015 9:14 AM

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Answer 1

Best reply

Averythomas

Level 4

1,524 points

May 30, 2015 9:20 AM in response to LukeLindblom

Checkout this program to control your fan speed manually, http://www.macupdate.com/app/mac/47386/macs-fan-control

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Answer 2

lkrupp

Level 6

14,488 points

May 30, 2015 11:01 AM in response to LukeLindblom

You have correctly surmised the issue. The sensor is no longer reporting to the operating system so the fan runs continuously. Your only choice is to take manual control of the fans but be warned that hardware damage can result if the internal temps are not controlled properly.

There is an excellent utility called iStat Menus that allows you to monitor most if not all of your iMac’s various sensors, fan speeds, CPU temp and activity, memory pressure, the list goes on and on.

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Answer 3

LukeLindblom Author

Level 1

30 points

May 30, 2015 11:19 AM in response to lkrupp

I repair computers, so I assumed it was that, but the constant fan, even while its asleep, is annoying. I guess the computer thinks the hard drive is overheated because the connector for the thermometer goes nowhere. How do I get "iStat Menus?". Is it in the Mac App Store? I see "iStat mini."

Thank you

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Answer 4

LukeLindblom Author

Level 1

30 points

May 30, 2015 11:29 AM in response to lkrupp

So there's no way to attach a thermal sensor to the actual Samsung drive? I don't want to damage my computer.

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Answer 5

kostby

Level 4

2,946 points

May 30, 2015 12:44 PM in response to LukeLindblom

Hardware sensor solution:

http://eshop.macsales.com/shop/imacdiy/

Software-only solution:

http://www.hddfancontrol.com/

Disclaimers: I have not tried the software-only solution.

I have purchased the proper hardware solution from OtherWorldComputing for my 21" mid-2011 iMac, but have not yet installed it because I've been too busy to clone and install the new 1TB hard drive.

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Answer 6

LukeLindblom Author

Level 1

30 points

May 30, 2015 12:46 PM in response to kostby

I started using "Macs fan control" from http://www.macupdate.com/app/mac/47386/macs-fan-control and it seems to help. I can leave the CPU and SuperDrive fans on auto but lower the speed on the SSD fan because SSDs don't get hot like the old hard drive would've. Thank you for your help!

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Answer 7

lkrupp

Level 6

14,488 points

May 31, 2015 3:52 PM in response to LukeLindblom

LukeLindblom wrote:

I repair computers, so I assumed it was that, but the constant fan, even while its asleep, is annoying. I guess the computer thinks the hard drive is overheated because the connector for the thermometer goes nowhere. How do I get "iStat Menus?". Is it in the Mac App Store? I see "iStat mini."

Thank you

http://www.macupdate.com/app/mac/25230/istat-menus

I see you have a good grasp on the situation. You’ll be fine.

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