iMac 27" (mid 2010): Will replacing the HD cause fan problems?

Question

Level 1

10 points

iMac 27" (mid 2010): Will replacing the HD cause fan problems?

Hi,

I have an iMac 27" (mid 2010). My HD is broken, and I'd like to replace it. I've already installed an SSD, so replacing the HD shouldn't be much of a problem.

However I've read that replacing the HD causes the fan to spin up all the time. Some sites say this started one generation later, but some remain unspecific or say that this problem affects all iMacs. Before I replace my HD, I'd like to know what to expect.

So my question is: in my 2010 iMac, can I replace the HD without causing fan problems (provided I put the temp plug in the right place 😉)?

Best regards,

F

iMac (27-inch Mid 2010), OS X Mountain Lion (10.8.4)

Posted on Jul 1, 2013 3:09 AM

Reply

Answer 1

Best reply

Chris Goulbourne

Level 1

104 points

Jul 1, 2013 3:12 AM in response to kingkaramel

So long as the temp sensor is in the correct place you should'nt have a problem

Reply

Answer 2

kingkaramel Author

Level 1

10 points

Jul 1, 2013 3:31 AM in response to Chris Goulbourne

So you're saying the fan problem really affects the 2011 models with 7 pin SATA connectors?

My conclusion is that since I now have a WD drive intalled I should be able to replace it with any WD drive with internal temp sensor. If I'm wrong, please correct me, otherwise I'll go ahead and order a drive this evening. 😉

I'm thinking of a WD20EFRX.

Reply

Answer 3

kingkaramel Author

Level 1

10 points

Jul 1, 2013 3:47 AM in response to kingkaramel

Argh, here it says the drive needs Apple's proprietary temp sensor:

change hard disk on imac 27" mid 2010

Does anyone know where I can find a list of compatible drives?

Reply

Answer 4

mende1

Level 10

93,538 points

Jul 1, 2013 3:50 AM in response to kingkaramel

Late 2009 and later iMacs have got the temperature sensor in the hard drive, so you will have fan problems. You just have to buy a hard drive that has got the sensor.

I recommend you to have a look at this OWC article, that includes an explaination and hard drives > http://blog.macsales.com/10146-apple-further-restricts-upgrade-options-on-new-im acs

Reply

Answer 5

Jul 1, 2013 3:51 AM in response to kingkaramel

The temp sensor is only in place with sticky padding you will be ok to use the old one providing it is stuck in place

Reply

Answer 6

kingkaramel Author

Level 1

10 points

Jul 1, 2013 11:35 PM in response to mende1

@mende1 - Thanks! I chatted with an OWC technician and ordered a compatible drive.

@chris - Unfortunately, there is no external sensor in these iMacs. It must be built into the HDs, which causes all the trouble...

Reply

Answer 7

mende1

Level 10

93,538 points

Jul 1, 2013 11:37 PM in response to kingkaramel

Now, you just have to install the hard drive and install OS X there. Good luck

Reply

Answer 8

kingkaramel Author

Level 1

10 points

Jul 1, 2013 11:55 PM in response to mende1

Thanks! I did the following two months ago, so I'm confident. And OS X is on the SSD, so I just have to move the data back to the HD:

http://www.twam.info/hardware/apple/installing-additional-ssd-in-mid-2010-27-ima c

Btw, I'm glad I decided against creating a Fusion Drive... 😉

Reply

Answer 9

mende1

Level 10

93,538 points

Jul 1, 2013 11:56 PM in response to kingkaramel

You are welcome

Reply

Answer 10

WZZZ

Level 6

13,220 points

Jul 2, 2013 4:27 AM in response to kingkaramel

OWC is mistaken. I don't know why they keep saying that. (I'm not even certain the OWC blog linked above related to using the same make drive on the late 2009s was ever correct. I had a long phone conversation with an upper level WD tech some time ago who said that the originals were special ordered by Apple.) Those drives have Apple proprietary firmware which puts the temp sensor output to the jumper block, and you cannot just replace with a drive of the same manufacturer. A non-Apple WD drive will not have that connection at the jumper block.

Two possibilities: Get an external stick-on temp sensor that will work with your model or use SSD Fan Control.

http://exirion.net/ssdfanctrl/

If I'm mistaken and you do get it to work directly with a replacement WD drive I will be pleasantly surprised, since I have a Late 2009 which will need a new drive sooner or later. Please post back with your results.

Reply

Answer 11

kingkaramel Author

Level 1

10 points

Jul 2, 2013 5:34 AM in response to WZZZ

Hi WZZZ,

what you write is what I read about 2011+ iMacs. The 2 preceding generations are said to work with certain models that do have an internal sensor, but not the special firmware. I'll report back.

Reply

Answer 12

WZZZ

Level 6

13,220 points

Jul 2, 2013 10:05 AM in response to kingkaramel

My post could have been more coherent. I was referring to the iMacs between the Late 2009 and the onset of the 2011 models. I'm not 100% sure about the WD drive compatibility issue, just that I have some serious doubts about whether OWC is correct about that. I do know that there have been any number of threads here for the Seagates, where people have reported that using another Seagate drive, even the exact same Seagate, was not compatible for those model years.

Since the output of the temp sensor is specially routed to the jumper block on either the WD or Seagate drives, I don't see why an ordinary after-market WD drive would have that.

I already obtained a stick-on temp sensor that I know will work for my model, and have that ready for if and when, as well as a new WD drive. I would love to hear that you get it working without doing that or needing SSD Fan Control.

Yes, please post back with your results.

Reply

Answer 13

kingkaramel Author

Level 1

10 points

Nov 10, 2013 7:31 AM in response to WZZZ

Took me a while because I first received a broken HD, then moved to a new house, went to hospital... but I can finally confirm that the WD20EZRX works as expected. The fan does not spin up. It did so when the HD slot was empty (SSD only), but a fan control software took care of that. Aside: even the broken ezrx I first installed prevented the fan from spinning up, but wasn't otherwise recognized by my system... 🙂

Reminder: it's -very- important to remember the exact position of the 4-connector sensor cable in the 6-connector socket of the HD. There are four possible ways of plugging it, and only one will work. It might be a good idea to take a photo, mark the cable, make a sketch, whatever...

Reply

Answer 14

WZZZ

Level 6

13,220 points

Nov 10, 2013 8:06 AM in response to kingkaramel

So SSD Fan Control took care of the HD fan issue properly?

Reply

Answer 15

kingkaramel Author

Level 1

10 points

Nov 10, 2013 8:42 AM in response to WZZZ

I used Macs Fan Control. I set the fan to a fixed rpm value and (better safe than sorry) increased the rate only when I worked on CPU intensive tasks. Not the most elegant solution, but better than the noise of the fan at full speed...

Reply