Need to recover SSD partition table using Gdisk on Samsung 512GB on MBP MID 2015

Most Apple SSDs have proprietary connectors. See https://beetstech.com/blog/apple-proprietary-ssd-ultimate-guide-to-specs-and-upgrades for reference. What type of an enclosure are you using to connect the Apple SSD?

Unless the disk was originally encrypted using FileVault2, GDisk should work. Did the disk stop working while it was installed as the internal disk?

After this, do you see the command line prompt?

Take a look https://eshop.macsales.com/Service/Knowledgebase/Article/26/788/Envoy-Pro-PCIe-Apple-SSD-Compatibility. Your Model MZ-JPV2560/0A4 is a Samsung SSD, and most likely an AHCI model.

If the original Apple SSD gets hot when connected to the internal connector, I suspect the controller on that SSD has failed.

There is a simple to use command "gpt" which can restore the partition table using the backup copy:

sudo  gpt  recover  diskN

Replace "diskN" with the current drive identifier for your drive. Make sure to get the drive identifier just before running the "gpt" command to make sure you are working on the correct drive. I have used this command to successfully restore the main partition table with the backup.

You need to decide how important this data is to you. If you run this command or any other command on this SSD you will be permanently modifying the SSD NAND where something important may be lost. You may want to consider a professional data recovery service such as Drive Savers or Ontrack. Both vendors provide free estimates and both are recommended by Apple. You may only have one chance at recovering the data from this SSD so choose wisely.

I hope in the future you will have frequent & regular backups including any external media with important & unique data.

Good luck.

BackBay wrote:

I think this implies that I have a backup copy of the partition table right? Which I don't. So this is why I asked if there was a way to make a binary backup above.

You can use the command line utility GNU ddrescue to make a bit for bit clone of a drive. I haven't used the macOS version in years, but you may need to install GNU ddrescue using Homebrew. While I've used GNU ddrescue to rescue failing hard drives I've never had the opportunity to try it with a failing or corrupt SSD.

In Gdisk? The data is meaningful and with vacation photos but really the main priority is getting at that seed phrase on Metamask. It is now worth $8700. If it comes to sending this overseas then yes I will have to do it but I am waiting to hear what Loner T recommends as I have read about his prior data victories on here. The disk had never had a problem then suddenly a power outage wrecks all partitions and recovery of them? I just don't see how that is possible.

In addition to normal file system corruption from improperly unmounting a volume SSDs are susceptible to power issues which can cause corruption of the SSD. At least you can still communicate with the SSD which is a good sign. Definitely work from a clone and leave the original SSD untouched as it may leave you options.

I holding out the hope that it is actually a simple fix for the person who has seen enough of this kind of thing happen. I believe it was just shut down improperly and mixed up, so there must be a process to straighten out the partitioning so the disk is readable again.

You can try using a data recovery app such as PhotoRec or TestDisk which don't require a mounted volume. I don't know if any other apps such as Data Rescue will work from an unmounted volume. Sometimes these apps will ask to modify the drive so just be careful as you don't want to make modifications to the original SSD. Typically for data recovery on failing hard drives I use GNU ddrescue to clone the drive, then I will use tools such as these on the cloned drive including the previously mentioned "gpt". If I expect I need to experiment, then I clone the drive to a raw image file so I can either work from a copy of the image raw image file or I can use it to clone the raw image to a good drive where it is easier to work than working from an image file.