Samsung T7 External SSD not recognized by Macbook Pro

Is this a laptop or Desktop system? If it is an M1 laptop, then did you approve macOS to access the external drive? Sometimes those prompts do not always appear & other times they can get stuck hidden behind other open windows. If the device has not been approved to connect, then you won't see the physical drive at all within macOS.

If you have an M1 laptop & have approved the connection, or you have a Desktop system, then within Disk Utility click "View" and select "Show All Devices". Do you now see the T7 physical drive on the left pane of Disk Utility? If not, then you have some sort of hardware issue or compatibility issue.

If the physical drive is seen, but you cannot see or mount any volumes.....maybe the previous owner has the SSD encrypted....possibly using Samsung's proprietary software to utilize the SSD's built-in hardware encryption feature. If that is the case, then the previous owner needs to turn off the SSD's encryption or reset the SSD using Samsung's proprietary software and the PSID Code found on the bottom of the SSD...the latter resets the SSD's hardware encryption keys so the SSD appears completely unformatted & unpartitioned to macOS.

TBreeze20 wrote:

I've never submitted a problem with Apple Support before so this is a first.

FYI, Apple is not here on this forum. We are just other users such as yourself.

Go easy on me please and thanks for your support if you do come across this. Take care friends.

You've done a good job providing us some of the background and have even presented it is an easy to read manner. You are off to a good start.

<< couldn’t make out what you’re were trying to say. >>

the default settings for Disk Utility in High Sierra and later show only Mountable Volumes. So a Volume that MacOS can not Mount, will not be shown AT ALL, unless/until you click the little drop-down menu that says "View" and select "Show all Devices"

To help make that more clear, I included a screenshot of what High Sierra with "Show all devices" looks like, above. The Volumes and partitions for each Physical device are shown indented under the device-name.

In that example, and eternal Physical device named "WDC WD800HLFS-75G6UI..." is shown, and

under it, its simple MacOS Extended volume named X11-Drv80.

I will post s "show only Volumes" view in the next message

(continued)

This is Disk Utility, also from High Sierra, showing only Volumes.

All the same Volumes are shown ONLY because all are MacOS Mountable Volumes. if I had installed drives with wacky-formats drives, the Volumes would NOT be shown in this "View"

Executive Summary: You MUST actively choose "Show all Volumes" from the Tiny "View" menu, or other unusual format drives may not be shown at all.

"Samsung T7 External SSD not recognized by Macbook Pro: I bought a Samsung T7 from a friend. I plugged into my Mac Pro (M1, 2020) (MacOS Sequoia Version 15.5) and while the ssd lights up, the Mac doesn't seem to recognize it at all.[...]"

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Seeing a Drive on a Mac:

A. Disk Utility in Recovery Mode:

Booting in Recovery Mode, go to Disk Utility, and then see if you can mount the drive from there.

B. Format to FAT32 on a Windows PC:

Using a PC, use Disk Management, and try formatting this as FAT32. Then, see if you can see it, formatting it accordingly.

C. Single-Out this User:

Create another Administrator user (not a guest user), seeing if it then works. IF so, then it is an issue with your current user. If not, then it is an issue with your entire Mac --perhaps a hardware issue.

"Samsung T7 External SSD not recognized by Macbook Pro: I think you’re onto something. The previous owner was a windows user and may have formatted it differently. Thanks for all of the other possible solutions as well!"

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You are welcome. FAT32 is readable by macOS and PC. So, formatting it to FAT32 would presumedly make it readable, through use of a PC.

Disk Utility is the grand Arbiter between bare drives and Mountable Volumes.

A drive that can not tell Disk Utility its make&model, and a reasonable non-zero size/capacity can not be erased, repaired or used in any way in its current condition.

this is what the "show all devices" view in Disk Utility should look like: