Data recovery for 2017 iMac Fusion Drive with undetected SSD and SMART errors

Question

Data recovery for 2017 iMac Fusion Drive with undetected SSD and SMART errors

Hello,

I have a 2017 27-inch iMac (iMac18,3) with a 2TB HDD and a suspected APFS Fusion Drive.

I booted Ubuntu 24.04 from a USB drive only to diagnose the storage issue. I have not intentionally written anything to the internal drives.

Diagnostic findings:

- The 2TB HDD is detected.

- SMART reports 832 Current Pending Sectors.

- SMART also reports 25 Reported Uncorrectable errors.

- A Samsung NVMe SSD controller (SM961/PM961/SM963) is detected via PCI.

- The NVMe SSD itself is not accessible as a block device.

- Linux reports the NVMe device as "Device not ready".

- APFS tools report that two devices are required for the Fusion Drive.

The data is extremely important and there is no backup.

I have not erased, reformatted, repaired, rebuilt, or reset the Fusion Drive, and I have not replaced either internal drive.

My questions are:

1. Could these symptoms indicate a failed or inaccessible SSD, a failed Fusion Drive member, or another hardware issue?

2. Is there any safe, non-destructive Apple-supported diagnostic procedure that can be performed without writing to either drive?

3. Is there any realistic way to recover the original APFS Fusion Drive data when the HDD is still detected but the SSD is not accessible?

4. Does Apple recommend any Apple Authorized Service Provider or specialist that can perform Fusion Drive data recovery while preserving both original drives?

5. Should both original drives be preserved and imaged before any repair, replacement, erase, resetFusion, or macOS reinstallation is attempted?

My priority is recovering the original data without modifying either drive.

Thank you.

Posted on Oct 17, 2026 5:07 AM

Reply

Answer 1

Oct 17, 2026 2:25 PM in response to Madadi-tavero

You will need to contact a professional data recovery service. You cannot do anything to recover the data yourself. Your Hard Drive has over 700 Pending bad sectors needing reallocation. Those sectors and any new ones which go bad while using the drive will cause you all sorts of problems since macOS is unable to handle those I/O errors. Trust me....more sectors are going to fail the more you use this Hard Drive. You will just make the drive failure worse trying to use macOS or any standard tools....even most data recovery software is made for use on a fully health drive.

As for the internal NVMe SSD......I don't know, but I suspect it may have failed....your information here is not clear.

In the future you need to make sure you have frequent and regular backups since it is nearly impossible to recover data from the internal SSD of the recent Macs due to all of the hardware, software, and security changes.

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Answer 2

Oct 18, 2026 11:58 PM in response to Madadi-tavero

The HDD may still contain recoverable data, but the SSD could be a separate point of failure, both may need to reconstruct the original Fusion Drive.

Since the data is irreplaceable and there is no backup,I'd recommend stopping running First Aid, resetting Fusion, or initialising drive, and you should consult a professional data recovery specialist locally or online, they will evaluate your case before attempting repairs.

If your SSD is TRIM enabled, it is not possible to rescue data from it. But if it is not TRIM enabled, there is still a chance of recovery for both of your HDD and SSD. If you are looking for quick solution, data recovery programs such as R-Studio, DMDE, Cisdem are worth a try. You can contact the support for details before any decision.

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Answer 3

Rudegar

Level 10

186,630 points

Oct 17, 2026 6:31 AM in response to Madadi-tavero

if it was me then I would disassemble the imac and remove the harddrive and place it into a external usb enclosure

and check if the data was available if it was not then I would look into various undelete tools to salvage the data

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Free Data Recovery Tool? : r/mac

of cause that would require another computer to use the external usb enclosure

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Answer 4

den.thed

Level 10

98,484 points

Oct 17, 2026 7:20 AM in response to Madadi-tavero

If you did not have a backup (Time Machine, CarbonCopyCloner, SuperDuper, a cloud service or something else) then there is a good chance that you have lost all or part of your Data.

If Rudegar's advice does not help, then your best hope is to take or send the drive(s) to an expensive professional data recovery service.

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