iMac not needed "Fusion" SSD overheating

[Joe Sheem]

Hello all!
The internal HD failed in my late 2013 27" iMac. I installed a 1 TB SSD in it's place, and it works just fine. However, in the 10 days since then I've been getting this error notitification from DiskWarrior (v5.0):

"DiskWarrior Hardware Test Notice - The hard drive's built-in temperature sensor indicates an above normal temperature of 141 F(61 C), this might indicate a failure or pending failure of that could result in loss of data"

Working with a technician from the company that sold me the replacement SSD, I saw in Disk Utility that the drive that's overheating is the 120 GB SSD that was originally paired with the disk-based HD that failed - the combination of the two was called a "Fusion Drive" at the time. I don't need this old SSD. I've erased and unmounted it, but I continue to get the overheating message.

I now know how to open up the iMac, but I don't want to if I can avoid it - as you know it's a big pain, especially with fresh double face tape holding the glass on. On the other hand, I would rather not have the iMac burst into flames, or toast some component inside...

Your thoughts?

 

[Juicy Box]

Did you de-fuse the original Fusion Drive? I assume you would of had to, otherwise I wouldn't think that your blade SSD wouldn't mount, but I am just checking.

You could increase the fan speed to cool down the overheating SSD.

The old HDD was much hotter than your new SSD, maybe there was always an issue with the SSD part of the Fusion Drive, but the increase cooling from the hot HDD kept it cooler.

 

[Deadeyeshark]

Did you attach a thermal sensor to the hard drive, I replaced the hard drive in my 2013 iMac 27” and bought a thermal sensor from OWC.

 

[McTinker]

When you placed the 1TB SSD, did you put back the temp sensor on the SSD? Maybe it's dangling right aboe the cou, because SATA SSD's usually don't get that warm. I have the same imac and I use Mac Fan Control who can use the temp sensor IN the SSD.

 

[Joe Sheem]

Did you de-fuse the original Fusion Drive? I assume you would of had to, otherwise I wouldn't think that your new SSD wouldn't mount, but I am just checking.

You could increase the fan speed to cool down the overheating SSD.

The old HDD was much hotter than your new SSD, maybe there was always an issue with the SSD part of the Fusion Drive, but the increase cooling from the hot HDD kept it cooler.

I didn’t do anything to “de-fuse” the old HD and the old (still installed) small SSD. I used the directions from the company that sold me the new drive, and they didn’t mention it. Increasing the fan speed sounds like a good idea — another poster below suggests an app for doing that. Do you know of another way to control the fan?
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I didn’t do anything to “de-fuse” the old HD and the old (still installed) small SSD. I used the directions from the company that sold me the new drive, and they didn’t mention it. Increasing the fan speed sounds like a good idea — another poster below suggests an app for doing that. Do you know of another way to control the fan?

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Did you attach a thermal sensor to the hard drive, I replaced the hard drive in my 2013 iMac 27” and bought a thermal sensor from OWC.

Thanks for asking - I guess it’s important! Fortunately the new SSD came with a temperature sensor and wiring, so I did.
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When you placed the 1TB SSD, did you put back the temp sensor on the SSD? Maybe it's dangling right aboe the cou, because SATA SSD's usually don't get that warm. I have the same imac and I use Mac Fan Control who can use the temp sensor IN the SSD.

Thanks for the App suggestion!

 

[Juicy Box]

Can you post what upgrade kit you used? Did it come with a temp sensor?

I didn’t do anything to “de-fuse” the old HD and the old (still installed) small SSD. I used the directions from the company that sold me the new drive, and they didn’t mention it.

By de-fuse, I mean separate the two internal drives of the Fusion Drive using Terminal. Did you do this?

Increasing the fan speed sounds like a good idea — another poster below suggests an app for doing that.

Assuming all of your temp sensors are okay, SW would be the best way for your. For SW, lot of people use "Macs Fan Control", but there are probably a few others to use.


I would look into this though:

When you placed the 1TB SSD, did you put back the temp sensor on the SSD?

I have read in the past that people using the external temp sensors with just a piece of tape was having them fall off after a while. I am unsure if this happened to you, or what the consequences would be, but this could be a part of the issue.

Others have recommended using glue to apply the external temp sensor to the new SSD.

 

[Joe Sheem]

Excellent questions!

Here's info on the kit I got from MacSales/OWC:

DIY Upgrade Bundle for 2012 or later 27" iMac's factory HDD: 1.0TB OWC Mercury Extreme Pro 6G SSD. Includes the NewerTech AdaptaDrive, components and tools.

I did not do anything in Terminal, to separate the Fusion Drive. It wasn't mentioned by OWC personnel or in the instructions. Should I do something now? I also didn't do anything to, or about the old SSD portion of the Fusion while the case was opened.

The OWC drive came with a new temperature sensor (and wiring harness) which I installed as directed, using the pre-attached double face tape, in the indicated location. But note that I'm not getting a warning message about that new drive. The message specifically mentions the old SSD. I suppose I might have knocked a temperature sensor on the old drive while I had the iMac open - I don't know where it is!

I'm new here: what does "SW" stand for? Self-something?

Thanks!

 

[Juicy Box]

I am wondering if not splitting the Fusion Drive might be the reasons for the overheating blade SSD. I have split fusion drives before, but not with a failed/removed HDD portion.

I also didn't do anything to, or about the old SSD portion of the Fusion while the case was opened.

Does the old SSD/Fusion Drive mount?

Should I do something now?

I am unsure if it is necessary to do with a failed HDD, but I would try to split the Fusion Drive using Terminal. Since you are booting from a different drive (the new SSD), you should be able to use the Terminal app in the Utility folder and not have to boot in recovery.

After splitting the old SSD, you can reformat and use it.

You might wanna have it for some things anyways, as the blade SSD on the 2013 should be faster than the SATA SSD that you replaced the HDD with.

Maybe someone else might add something about this, because I never ran into this issue.

I'm new here: what does "SW" stand for? Self-something?

Software

 

[Nguyen Duc Hieu]

What I understand is:
1. Your iMac has a temp sensor attached to a hot drive.
2. Diskwarrior warned you about it.
3. You are sure that you don't want to use that drive anymore, but you don't want to get messy by opening the iMac to remove it and attach the temp sensor to your good-and-cool SSD.

My suggestion is: Remove Diskwarrior or ignore its messages.