SD card erasure error - Erasing "Apple SDXC Reader Media" ?

The 1969 date is a red flag — that's Unix epoch zero, meaning the card's filesystem metadata is completely gone. Some SD cards lock themselves into read-only mode when their internal controller detects too many errors, and no OS-level tool can override that because it's happening at the hardware level.

Before giving up, try this in Terminal — first run

diskutil list 

to find the exact disk identifier (something like disk4), then:

diskutil eraseDisk ExFAT SDCARD /dev/disk4

Replace disk4 with whatever shows up for the SD card. Sometimes this gets through when Disk Utility's GUI can't.

If that also returns an error, the card is most likely finished. Flash memory has a limited write cycle lifespan and once the controller locks it, there's usually no way back. Not worth spending more time on it.

For some unknown reason, sometimes the first attempt will fail, but if you immediately try to erase it again, then it may actually succeed.

Also, you should erase the whole physical drive as described in the following Apple article:

Erase and reformat a storage device in Disk Utility on Mac - Apple Support

What partition type & file system to use depends on what other devices you will use with this SD Card as each device (camera, TV, etc.) will have its own requirements. If it will only be used with macOS, then GUID & APFS are fine. Or if only used between macOS & Windows, then GUID & exFAT. If the SD card will be used by a camera, TV, or other non-computer device, then following the guidelines of that other device (camera, TV, etc.).

Edit: Actually the following link to an older version of the Apple article found on the Internet Archive's Wayback Machine is better than the one I linked above since Apple has severely degraded the quality of information & details on the newer version of their articles:

https://web.archive.org/web/20250909095655/https://support.apple.com/guide/disk-utility/erase-and-reformat-a-storage-device-dskutl14079/mac

Some SD Cards have a sliding toggle on the side of the SD Card

In one position, it will allow the user to Read and Write to the SD Card

In the other position, it Locks the card from reading and writing

Helops wrote:

Thanks,

I am only allowed to read the card.

Although I bought it new, only I used it, and I have a bunch of files on it.

Have you written files to this SD Card on this particular Mac before this issue occurred?

If so, what has changed since that time?

What other computers (and versions macOS) and devices have been used with this card?

You can still read the files stored on this card?

Suddenly it does showed date of creation 1969, does not let me erase it, no matter of the slide position.

Can it be somehow erased, or should I just throw it away?

What is the exact make & model of this SD Card?

Was it purchased directly from a respected vendor and not some marketplace vendor for a "respected" vendor? Unfortunately these days most online vendors also allow other people to sell products on their website. For example, while Best Buy website has their own merchandise listed, they also allow other people to sell products through the Best Buy website and are considered marketplace vendors riding on the coat tails of the major "respected" vendor. Unfortunately these marketplace sellers punting their products on a major vendor's website like Best Buy can be unscrupulous and can sell used or counterfeit products as "new". There are a lot of these scam sellers offering up fake & counterfeit drives where you may only realize it when you try to erase them with a different partition & file system. Some of these fakes are very hard to detect, others are very obvious if examined more closely.

You never mentioned the file system used on this SD Card.

Are you using the SD Card manufacturer's software to manage the SD Card?

Have you tried using an SD Card Adapter instead of the SD Card slot in the Mac? I have seen multiple reports on this forum where the built-in SD Card slot in the Mac is unable to work with some cards.

Have you tried erasing the SD Card using another computer, especially a Windows computer?

See if you can erase the SD Card while booted into Safe Mode.

Use terminal commands if needed for low-level formatting. Test the SD card in another device to see if it's recognized or write-protected.

Helops wrote:

I was trying for some months to repair//erase those cards.

Believe it or not - after running the commands in Terminal, one of them functions fine.

Could you please explain what it means:

qvd@dgan ~ % lsof +f -- <mountpoint or device>

zsh: parse error near `\n'

The "<mountpoint or device>" part should actually contain the path to the mounted volume ( such as "/Volumes/MySDCard") or to a device identifier (such as "/dev/diskXsY" where "X" & "Y" are numbers for the drive/device and partition respectively).

qvd@dgan ~ % Isof

zsh: command not found: Isof

I'm not sure since you did not have that error with the previous commands. Either some hidden non-printable character got embedded there or you have a problem with the PATH for zsh.

I'm not sure why you would need to run the "lsof" command since the Disk Utility error is not due to any process holding onto the volume. The Disk Utility error you reported original said it could not modify the partition map. With your later comments you say you cannot write to this SD Card....I'm assuming you mean you cannot transfer any files to this SD Card.

Helops wrote:

Yes, it couldn't modify the partition map.

I'm trying and trying because I want to understand.

I know the Apple forums have been having a lot of issues this week in addition to the chaotic ordering of posts with the default "Ranked" ordering of posts.....all of which can make it difficult to follow the progression of posts in a thread so it is easy to overlook posts.

Please provide answers to the questions I asked in one of my earlier replies here:

SD card erasure error - Erasing "Apple SD…-- Questions Asked by @HWTech Which Need Answers - Apple Community