Corrupted internal MBP SSD won't erase Unable to write to last block of the device

How to Create a Bootable USB Installer. Once created, shutdown computer and disconnect all external drives except the newly created installer. Connect to charger and startup computer and immediately hold Option key. This should present to Boot Manager and choose Install Mojave USB drive. Once it loads, choose Disk Utilities >> View >> View All attached devices. Look for upper most drive usually called Apple SSD. This is the drive one want to Partition as Single Partition. Format it as APFS and Scheme: GUID Partition Map. If it is successful - back out of Disk Utilities and choose Install macOS.

Notation: Just noticed in screen shot lower right S.M.A.R.T Status: Not Supported - could mean drive is failed or failing but would get second opinion on that.

I think you have posted about this problem (fails writing to the last block) in two other posts here,

https://discussions.apple.com/thread/252436378

https://discussions.apple.com/thread/252435975

but each of your separate posts does not explain fully other background info that are in your other posts. This may result in different suggestions, which may be what you are looking for ... but ...

... as R. Phillips noted, your drive may be failing. This has also been suggested in your other separate posts about the same problem. based on symptoms that you described.

If you can create a standalone USB bootable drive, from that external bootable drive with Disk Utility you might be able to select the option to complete the reformat process of writing zeros across the entire drive, which could take 24 hours or more. This might succeed in bringing your drive back into usable condition if it is indeed retrievable.

wild-blue-yonder wrote:

1. Thank you both! Yea my prognosis of the problem went from trying to salvage my OS > trying to recover data before erasing the disk > not being able to erase the disk, and since I don’t have my computer I haven’t found a way to delete my old posts. Thank you so much for the help.

I’m having a friend help me out tomorrow, how does this plan seem? Should I switch the orders of 1-3?

get a bootable USB installer, try to see if its disk utility could do what the internal Recovery couldn’t.

2. If the above fails, get a USB booter of Parted Magic and see if it fixes it

3. if the above fails, overwrite the drive with 0’s via terminal

4. if any of the steps successfully erases the computer, install the new OS again, and then run diagnostics to see if my SSD is still healthy (do you guys have any recommendations on what tests to run?)

Thanks again, you guys have been really helpful in this stressful time.

For drive diagnostics (physical drive health), I think DriveDX is the one I would use.

You could reverse the order of 2 or 3 in your plan. Parted Magic requires following a specific and somewhat involved procedure that was outlined in great detail by HWTech in an earlier post you had referred to.

Good luck with all of this. I fear that the drive is failed or failing but you may be able to rescue it.

wild-blue-yonder wrote:

Thank you! Is step 2 “better” for the health of my drive though? Because I’d rather do that first even if it’s more work.

In principle, step 3 would cause a bit more wear on an SSD, yes.

Excellent work there @ steve626 +1