A colleague at work has a Kingston 240GB SSD drive which has come out of a now dead computer. We want to be able to recover some data from it (no backups sadly) however the drive won't mount properly.

I am using an Anker USB3 external HDD enclosure which I know to be working correctly. The drive has come from an Apple computer, and we are attempting recovery on another MacBook Pro.

The drive appears under DiskUtility, however is greyed out. Trying to click mount does nothing. FirstAid also fails.

What Have We Tried?

So far, we've run diskutil repairVolume disk2s2 which gave the following output:

Repairing file system
Volume is already unmounted
Performing fsck_hfs -fy -x /dev/rdisk2s2
Checking Journaled HFS Plus volume
Invalid record count
Checking extents overflow file
Invalid record count
The volume   could not be verified completely
File system check exit code is 8
Restoring the original state found as unmounted
Error: -69845: File system verify or repair failed
Underlying error: 8: Exec format error

We have also run sudo /sbin/fsck_hfs -yprd /dev/disk2s2 which returned:

/dev/rdisk2s2: starting
journal_replay(/dev/disk2s2) returned 0
    Using cacheBlockSize=32K cacheTotalBlock=65536 cacheSize=2097152K.
   Executing fsck_hfs (version hfs-407.50.6).
** Checking Journaled HFS Plus volume.
hfs_swap_BTNode: invalid forward link (0xFFFFFFFF)
hfs_swap_BTNode: invalid backward link (0xFFFFFFFF)
hfs_swap_BTNode: invalid node height (255)
hfs_swap_BTNode: invalid record count (0xFFFF)
   Invalid record count
(4, 25511)

...repeats similar output...

Node 35746's back link is 0x0; expected 0x8c17
    disk offset = 0x78f41000, size = 0x2000
   Invalid sibling link
(4, 35746)
Node 35746's forward link is 0x0; expected 0x6489
    disk offset = 0x78f41000, size = 0x2000
   Invalid node height
(4, 35746)
Index key doesn't match first node key
   Invalid index key
(4, 35746)
** The volume   could not be verified completely.
    volume check failed with error 7
    volume type is pure HFS+
    primary MDB is at block 0 0x00
    alternate MDB is at block 0 0x00
    primary VHB is at block 2 0x02
    alternate VHB is at block 467182910 0x1bd8a53e
    sector size = 512 0x200
    VolumeObject flags = 0x07
    total sectors for volume = 467182912 0x1bd8a540
    total sectors for embedded volume = 0 0x00
    CheckForClean - could not get VHB/MDB at block 467182910
    CheckHFS returned -1317, fsmodified = 1

What Next?

I am hopeful that with the drive being recognised, the data is still recoverable. Before looking at paid software such as DiskWarrior, is there anything else that I can try so that I can access the disk or to repair this record count problem.

  • 1
    Simply stated, that drive is dead. But to clarify, first you say this: “A colleague at work has a Kingston 240GB SSD drive which has come out of a now dead computer.” And then say, “…however the drive won't mount properly.” First question I have is what do you believe is “dead” in the dead computer? If all of the components work, the computer should work. And then following up with that, the drive seems dead. An external enclosure can be “seen” by the OS even if no drive is connected inside of it. An external enclosure is a bridge. So you are not seeing the drive but the bridge. Jan 23, 2019 at 14:45
  • Hi @JakeGould, I do see the enclosure in DiskUtility, but I also see the drive "Untitled" under the enclosure - it also reports OS Extended (Journaled) and the correct 240GB capacity. The old computer had problems with the screen and keyboard and belongs to a friend of my colleague, so I'm several people down the chain from the original problem. I don't know the full details, but the drive was removed before the other components were repaired, and then wasn't replaced as the data was more important. Does this seem like a hardware failure, or just corrupted sectors (forgive my terminology). Jan 23, 2019 at 14:54
  • Well, what OS was this drive formatted in? If it’s from another macOS machine, I would say that drive is 100% dead. But if it’s from a Windows machine and formatted in a way macOS cannot recognize, that could be a factor as well. If you have access to a Windows machine I would just bring the drive over to it and see if it can be mounted there. And if it can’t? Sad to say it’s dead. Jan 23, 2019 at 15:02
  • It was from a MacOS machine, so I had hoped we'd just plug the drive in and grab the data from it. My assumption was that the screen/keyboard were the real cause of the original computer not working. If the data is still stored on the drive, am I not able to repair or rebuild the "sector information" so that this is accessible? Would DiskWarrior have any chance of recovery? Jan 23, 2019 at 15:14
  • 1
    It's not bad news for me as I keep several backups! But I understand - a power surge can damage the DRAM chips without me being able to see. I'd have thought that sort of case would prevent the drive showing up in DiskUtility. I was being optimistic, but I shall go share the bad news! Thanks for your help Jake Jan 23, 2019 at 16:42

2 Answers 2


You can try some of these for free. They will report back what they find and you pay to recover the files.

"Stellar Phoenix Macintosh - Mac data recovery software, recovers data from damaged, deleted, or corrupted volumes and even from initialized disks." They have a trial version, so I guess you can see if your data can be recovered... http://www.stellarinfo.com/mac-data-recovery.htm

"Data Rescue II is the best data recovery software on the market for recovering files from a problem hard drive. Data Rescue II works when other tools fail. Data Rescue II is also completely safe to use since it does not attempt any risky repairs to the drive while its scanning." http://www.prosofteng.com/products/data_rescue.php

FileSalvage is an extremely powerful Macintosh application for exploring and recovering deleted files from a drive or volume. FileSalvage is designed to restore files that have: -- been accidentally deleted. -- become unreadable due to media faults. -- been stored on a drive before it was re-initialized/formatted.


Wondershare Data Recovery for Mac

"Recover lost photos, video, documents, email and archive files from any Mac-based hard drive or external hard drive, iPod, USB drive, SD card, digital camera, mobile phone, and MP3/MP4 player, due to accidental deleting, formatting, virus infection, improper operation, unexpected power failure, and other unknown reasons. Also, iPhone recovery allows you to recover lost photos, videos, SMS, contacts, note, calendar and call history from iTunes backup file. With the free trial, you can preview all your recovered images, videos, music, documents and archive files prior purchasing this Mac Data Recovery." http://software.bigbigsoft.com/data-recovery-mac

"If there is any chance of recovery at all your best bet is Prosoft Data Recovery." by macjack https://www.prosofteng.com/datarescue-mac-data-recovery/


Try copying the disk byte by byte and then recover it. It's not a good idea to write into the disk (e.g. repair it) as it might have been damaged. It's a good idea to minimize its read, and scan though the backup using various softwares instead.

You may do that through payware like Disk Drill (which can then scan the whole backup image for files) or simply using a copy tool like dd.

You may run "man dd" to learn more and customize your usage, or copy your disk to your folder by running "dd if=/dev/disk2 of=/path/to/your/folder". When you are finished, simply rename the file to .dmg and attach it. If it successfully mounted, copy your files to a new drive. If it doesn't, try the following command: "hdiutil attch -nomount /path/to/dmg/file" and then "fsck_hfs -dfy /dev/diskXsX" (replace XsX with what hdiutil give you).

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