2017 21.5" iMac - What SSD Replacement?

[Buadhai]

The SSD that came with my 2017 iMac is failing. I need to buy a replacement. I have no idea what to buy. For example, will a Western Digital PCIe Gen3 x4, M.2 2280-S3-M (WDS500G2X0C) work?

If not, what should I look for?

 

[Cookie18]

Yes, that is the type you need.

Check out this link too: https://www.ifixit.com/Guide/iMac+I...K+Display+(2017)+Blade+SSD+Replacement/101104

 

[Buadhai]

Thank you.

 

[Fishrrman]

What leads you to believe that it's failing?

 

[Buadhai]

Carbon Copy Cloner (CCC) started reporting errors when cloning the startup drive. I wrote to Bombich software and received a reply from Mike Bombich which including the following:

I suspect the internal SSD may need to be replaced.

I booted in recovery mode and tried to repair the startup volume using Disk Utility. DU reported errors that it could not repair.

If I try to copy one of the failed files from the command line using cp I get this:

MrMuscle:/ mnewman$ cp "/System/Library/Accessibility/BundlesBase/com.apple.LookupViewService.axbundle/Versions/A/Resources/ca.lproj/Accessibility.strings" ~/Desktop
cp: /System/Library/Accessibility/BundlesBase/com.apple.LookupViewService.axbundle/Versions/A/Resources/ca.lproj/Accessibility.strings: Device error

I also tried cloning using CCC to a different external drive and received identical errors. So, it's not the external drive causing the errors.

I'm wondering if erasing the internal boot volume and cloning back from a known good CCC clone might solve the problem as SMARTReporter has never found a problem with the boot drive.

 

[Buadhai]

iMac Intel 21.5" Retina 4K Display (2017) Blade SSD Replacement

Use this guide to replace the Apple custom blade SSD (NVMe/PCIe x4). This guide is intended for iMac Intel 21.5" EMC 2545 models that are equipped...

www.ifixit.com

You know, I've replaced batteries and upgraded RAM and drives in several laptops (MacBooks) and a Mac Mini, but I just don't have the confidence to take apart the iMac. My goodness. Sixty steps plus that adhesive.

 

[Cookie18]

You know, I've replaced batteries and upgraded RAM and drives in several laptops (MacBooks) and a Mac Mini, but I just don't have the confidence to take apart the iMac. My goodness. Sixty steps plus that adhesive.

Haha it looks scary but I've done it 3 times so far, it's a lot easier than it seems.

 

[Buadhai]

Now I'm wondering if it was the drive after all. I ran CCC several times to three different external drives. Every time it complained about the same files. So, I had a look at those files and they were all corrupt. Most of them were small system files like this:

/System/Library/Accessibility/BundlesBase/com.apple.LookupViewService.axbundle/Versions/A/Resources/ca.lproj/Accessibility.strings

Those same files were fine on an older CCC clone.

While doing this (mounting and unmounting backup drives) I noticed that Disk Utility was incredibly slow at loading all the attached drives.

So, I again booted into recovery mode and ran First Aid on the boot drive. It still complained, so I did a system reinstall while still in recovery mode.

After booting normally, DU loaded all the drives instantly and all the system files that CCC complained about are no longer corrupt.

So, we'll see how it goes as time goes by.

 

[Fishrrman]

Good that you found what may really be the problem.
You would have "replaced" a perfectly good SSD.