iMac Mid 2011 - HDD Fans running at high speed

Joined
Feb 17, 2019
Messages
1
Reaction score
0
Points
1
I just picked up an used 27" iMac 2011 for myself two days ago. (500GB HDD and 4GB Ram) Everything is seemingly fine with the machine, except that the apple hardware test completes with the following error: "4SNS/1/40000000: TH00-9.000". I also noticed the HDD fans becoming noisy and spinning all the way up to 35-70% (checked in iStat Pro) under lightweight web-browsing tasks. I looked it up and found the issue to be of HDD fans and it said when you replace the original HDD with a 3rd party HDD, you are also suppose to add a thermal sensor to it. So, I am assuming this is what happened here or perhaps the original thermal sensor is malfunctioning.

Now, I want to fix this error as well as add an additional SSD to it while also upgrading the ram. But I am confused on how to go about this, particularly because under iStat Pro the HDD temp readings does show up. From my understanding, if the thermal sensor from the current HDD are indeed missing or damaged then iStat Pro shouldn't be able to display those thermal readings, right?
Also, without opening up the iMac is it possible to know whether the current HDD is a 3rd party or do I still have the original Apple HDD installed? (Under System Report the current HDD is called 'ST500DM002-1SB10A)


Let's assume that the thermal sensors are indeed missing, I've two ways to go about fixing this:
a) I can ask my local Apple repair shop (3rd party service provider) to replace the current HDD with an original iMac 2011 HDD (They have a bunch of dead iMacs anytime).
or
b) I can get an OWC Thermal Sensor kit and add that to the current HDD, possibly fixing the error. But the shipping and import duties makes it more expensive than the first option.

So which option should I be picking here?

I also want to install an SSD alongside and for that I only need the OWC SSD Drive Kit, or do I also need a separate thermal sensor kit for the SSD also?

For the RAM, I am planning to go ahead with one of the following rams:
https://www.crucial.com/usa/en/ct4g3s1339m
https://www.skhynix.com/eolproducts.view.do?pronm=DDR3+SDRAM&srnm=HMT351S6BFR8C&rk=20&rc=module
https://www.crucial.com/usa/en/ct102464bf160b

Are all of these Rams compatible?

Lastly, I am also looking to get the CPU and GPU re-pasted. Is there anything here to keep in consideration?
 

chscag

Well-known member
Staff member
Admin
Joined
Jan 23, 2008
Messages
65,248
Reaction score
1,833
Points
113
Location
Keller, Texas
Your Mac's Specs
2017 27" iMac, 10.5" iPad Pro, iPhone 8, iPhone 11, iPhone 12 Mini, Numerous iPods, Monterey
That's a very ambitious project you're undertaking.

1. The HDD that you now have appears to be a Seagate 500GB model. In 2011 you could order a 500GB or 1TB HDD for that model. Not sure if it's an original but the error you're getting is definitely thermal.

2. If you replace the HDD, get the OWC thermal sensor kit. It's very unlikely you'll be able to get hold of a proprietary replacement HDD. In case you're not aware, Apple has declared the 2011 model Macs as vintage. I don't know where you're at, so that might vary with your location.

3. The OWC SSD kit will include any thermal sensor needed and the adapter bracket with cables.

4. OWC and Crucial is our recommendation for memory modules. Buy from them and you'll get the correct memory.

5. Repasting the CPU and GPU should be done by someone who has experience with that. I'm not sure of the disassembly instructions but you can check for yourself at www.ifixit.com.

Lastly... be careful of how much money you're putting into that machine. You don't want to spend more than it's worth and keep in mind that it's already around 8 years old and can only run up to High Sierra for its macOS.

And, Welcome to our forums!
 

Shop Amazon


Shop for your Apple, Mac, iPhone and other computer products on Amazon.
We are a participant in the Amazon Services LLC Associates Program, an affiliate program designed to provide a means for us to earn fees by linking to Amazon and affiliated sites.
Top