APPLE SSD AP0256Q Media erasing error (-69877)

Use Disk Utility to erase an Intel-based Mac

Use Disk Utility to erase a Mac with Apple silicon

It is the use of the Disk Utility that results in the error message referenced, so the referral to use the tool that produces the error doesn't help.

I lost power while my Mac was running a backup, and the backup disk was corrupted/damaged. Hard drive repair using the tool didn't work, so I attempted to erase it, so it could be reformatted and used again - and "Couldn't open device. : (-69877)" is the resulting error.

Is the external disk just a brick now, or is there some response to this error?

This was the only post on this error (-69877) ... I went through all the steps indicated to erase the external drive, and the error resulted. I can find no solutions to this error that don't reference taking the steps which produce it. (In other words, taking the steps which produces the error is not a solution to resolving it.)

Thanks for responding, but after spending hours across days, I'm considering the external hard drive a brick, and am sending it to its final resting place.

One last shot - Restart in Recovery Mode - Intel Command + r

Or Apple Silicon  Choose Apple menu > > Shut Down.

2 - Press and hold the power button on your Mac until you see “Loading startup options.”

3 - Click Options, then click Continue. 

4 - Top Tool Bar >> Utilities 

Then perform the Reformat of the External Drive..

Restart in Normal Boot and test

I have had issues erasing the physical drives as well, but so far immediately attempting to erase the whole physical drive again as mentioned by @P. Phillips has allowed the drive to be erased. Disk Utility seems to get confused at times needing to have to repeat the process again.

If this is a brand new drive and you are having trouble erasing it to use a native macOS file system, then sometimes macOS & Disk Utility can have issues erasing drives which were partitioned & formatted by other systems. When this happens, I will write zeroes to the beginning of the drive to destroy the partition table so the drive appears completely blank to Disk Utility which usually allows Disk Utility to properly erase the drive. To do this you need the macOS drive identifier for the drive which can be retrieved from Disk Utility. The macOS drive identifier is in the form of "diskX" such as "disk3". Once you have the correct drive identifier you will need to issue the following commands in the Terminal app (make sure to replace "diskX" in each of the commands with the correct drive identifier for your external drive):

Unmount all volumes on "diskX":

diskutil  unmountDisk  diskX

Write zeroes to the beginning of drive "diskX":

sudo  dd  if=/dev/zero  of=/dev/diskX  bs=100m  count=10

This last command will prompt you for your admin password, but nothing will appear on the screen as you type the password, so press the "Return" key to submit the password. If there are no errors, then you should be able use Disk Utility to erase the physical drive as GUID partition and the file system of your choice. Keep in mind if you use the wrong drive identifier, then you will destroy all data on the drive with the drive identifier you supplied when replacing "diskX" in the above commands.

However, I did see another recent forum post where it appeared the latest macOS Monterey update may have broken something here for one user, but I have not seen a wide spread issue on these forums when it comes to using Disk Utility erase an external drive using a native macOS file system (MacOS Extended, APFS, exFAT). If you are trying to erase the drive with NTFS file system, then it is a known issue that a recent macOS update broke the third party NTFS driver, so you will need to use a native built-in file system instead.

Make sure to connect the drive directly to the Mac in case an adapter, hub, or dock is causing problems. With some drives, you may need to use a power supply for the drive, or connect the drive to a powered USB3 hub to supply more power to the drive. Also try disconnecting all other external devices in case one of them is causing a problem

Or maybe your new drive has a hardware or cable issue.

Thank you, the recovery mode approach @ P.Phillips suggested worked on the second attempt (it couldn't find the drive the first attempt), so I didn't need to take the steps suggested by @ HWTech.

I wish I'd posted days ago at the beginning of everything. (The first disk utility attempt took so long I had to shave again) Thanks for the help.

What your posting is referencing is not specific to Original Posting.

Your is related to an External Drive

Erase and reformat a storage device in Disk Utility on Mac

Good advise from @ HWTech - nothing lost and all to gain.

Do keep us posted on the progress - time permitting

That is good new :-)