How do you interpret "Hard drive temperature sensor" to determine next steps?

[apsinger]

Happy New Year's! (not so much so far!!)

2012 core I5 iMac stopped working and will not load......starts to load on the white screen, but then shuts off after about 30 seconds.

Ran the Apple Hardware Diagnostic and got error: 4SNS/1/40000000: TH00-9.000.

This error seems to be related to a Temp Sensor on the HD. (Of note, i had to use the Mac Fan Control application recently to turn down the fan as it was running at full tilt).

No....I dont have my data backed up, but Icloud has most of the pictures, etc at least.....

I was able to run the Disk Utility and tried to repair the disk.....get an error:

Verify and Repair volume "Macintosh HD".
Repairing file system.
Checking Journaled HFS Plus volume.
Checking extents overflow file.
Checking catalog file.
The volume Macintosh HD could not be verified completely.
File system check exit code is 8.
Updating boot support partitions for the volume as required.
Error: Disk Utility can't repair this disk. Back up as many files as possible, reformat the disk, and restore your backed-up files.
Error: Disk Utility can't repair this disk. Back up as many of your files as possible, reformat the disk, and restore your backed-up files.


Do i have to open this up and maybe replace the HD.....or the cable/sensor.....or do I try to just reload OS X without opening it up???


Sure appreciate any advice....my wife is unhappy and hoping I can fix that at least!

 

[chscag]

You need to replace that hard drive. However, the hard drive used in your iMac is proprietary and will either have to be replaced with the same one or compensate for the hard drive temperature sensor with a special cable from Mac Sales. And if your iMac has a defective hard drive temperature sensor in addition to the bad hard drive, you'll need to replace that also.

Unless you're skilled at taking an iMac apart and doing the work yourself, we advise taking the machine to Apple and let them do the repairs. The breakdown and take apart instructions for your iMac can be found at www.ifixit.com. The special cable can be purchased from www.macsales.com.

 

[apsinger]

And if your iMac has a defective hard drive temperature sensor in addition to the bad hard drive, you'll need to replace that also.

That sensor is part of the motherboard or logic board? I was hoping that was part of the HD......

 

[chscag]

The temperature sensor is on the logic board. The 2012 iMac has only one fan unlike previous models that had three fans. The sensors control the speed of the fan which is why if you don't replace the hard drive with an exact Apple replacement the fan will rev up to max rpm. The cable that Mac Sales sells allows you to use any ordinary hard drive or SSD as a replacement. Did you go to the ifixit web site to get an idea of the work involved and where the sensors are located?

 

[apsinger]

My mistake....its actually a 2011 iMac (21.5-inch Mid 2011)

Had trouble finding the right guide....ill go look again.

 

[Thumpernator]

The temp sensor is internal of the hard drive on your 2011. You could do what I just did in my 2011 and that is to replace the HD with a SSD from MacSales. They have a complete kit that is a piece of cake to install. You could then attach your original HD as an external and boot up from it. Download and use Carbon Copy Cloner to clone the original HD and then transfer it over to the new SSD.

I picked up an external enclosure for about $15 at Best Buy in order to attach the external HD.

Now, I'm not one of the really smart Guru's here, so there might be a better way. But this is what I did with my mid-2011 with a slight variance.

 

[apsinger]

Hi Dave....sounds awesome! So the fact I cant boot now is probably not an issue.....you suspect the temp sensor is preventing me from booting now?

Just trying to make sure i get the right plan together.

 

[Thumpernator]

Hi Dave....sounds awesome! So the fact I cant boot now is probably not an issue.....you suspect the temp sensor is preventing me from booting now?

Just trying to make sure i get the right plan together.

That question is better answered by chscag or one of the other (what I call) Guru's here. My input was based on the assumption that the temp sensor IS keeping it from booting. If so, it's not hard to change out the HD with a SSD yourself. Watch the video on replacing a HD on the Mac Sales site. Don't watch the one on ADDING a SSD, as it's much more involved and is not what you're wanting/needing to do.

 

[Thumpernator]

This is the item I used from Mac Sales. https://eshop.macsales.com/item/Other%20World%20Computing/KITIM11HE1TB/

 

[chscag]

Since your iMac is a 2011 model, the temp sensor for the hard drive is as member "Thumpernator" indicated. However, I would still replace the hard drive as it's very likely on its way out and will give you more trouble and corruption. And as we indicated above, the 2011 model has three fans: Hard Drive, Optical Drive, and CPU - all controlled by temp sensors. You already have the URLs for Mac Sales and ifixit. By the way, hard drive replacement for the 2011 model is easier than the newer models but still a complex process.