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Boot Question Mark. Unable to write to last block of the device

Hi, I am having trouble with my MacBook Air a1465. Turning it on displays an image of a folder with a question mark inside. Looking for how to solve the problem, I tried to clean the NVRAM, with ALT + CMD + P + Q. NVMRAM was successfully cleaned but the issue was not resolved so I tried to reinstall the system through OS X Utilities. When turning on the computer I press the CMD + R keys, I correctly enter OS X Utilities. If I select Reinstall OS X option, a screen opens to install OS X Mountain Lion, but when selecting the disk no disk appears. Again in the menu of OS X Utilities, I enter the DIsk Utility option, here if the disk appears (120gb SSD), but when trying to format it or create a partition after a few minutes an error appears "Unable to write the last block of the device ”, and the disk disappears from the list. To see the disk again I have to clean the NVRAM again.


I tried erase with the formats Mac OS Extended (Journaled), Mac OS Extended (Journaled, Encrypted) and the message is always the same. I also tried to create a partition that occupies the entire disk with the same two formats, and I also get the same error .


I also tried to create a disk image so I could restore it later. I select New Image, try to save it to an external disk, and after a few minutes a message appears saying that the device is not configured.


I also want to comment that you start a Linux Live-CD, the computer starts correctly, but it never detects the disk, neither when installing the OS from the Kali Linux installation menu, nor after booting the Live-CD with the command fdisk -l.


I attach an image with information from the disc.


TOSHIBA THNSN2128GSPS



Is there a way to do a complete formatting of the disk? Or should I buy a new ssd disk?

MacBook Air 11″, macOS 10.13

Posted on Jul 16, 2020 2:42 PM

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Question marked as Top-ranking reply

Posted on Jul 17, 2020 1:32 AM

Were you able to give the SSD a proper format?


In order to install 'the Installer' on the internal SSD then

use it, that SSD requires the partition map to be APFS as

stated in the instruction, before it will see a supported OS.


When you click in the 'Base System' what does that show?

Were you able to use macOS Utilities to erase partitions &

then have Utilities write the APFS file system to the SSD?


If you have another Mac, what system does it use? If you

bought a quality replacement SSD of capable specs, and

had an external enclosure (correct to the idea) a macOS

can be installed on there; then test ran. What you get first

seems to be an installer. But it's not found the APFS base.


• File system formats available in Disk Utility on Mac - Apple Support

https://support.apple.com/guide/disk-utility/file-system-formats-available-in-disk-utility-dsku19ed921c/19.0/mac/10.15


The correct path to ready an 'installer' so it has place to run

is in these instructions; see APFS. The SSD may have issues.

However the direction you took it, did not resolve anything.


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

https://support.apple.com/guide/disk-utility/erase-and-reformat-a-storage-device-dskutl14079/19.0/mac/10.15


You may need to first 'correctly identify' the MacBook Air

because model A1465 isn't enough; Apple re-used those #.

[There were Eight build models - with MacBook/Air A1465.]


• Lookup Mac Specs By Serial Number, Order, Model & EMC, etc @ everymac.com

https://everymac.com/ultimate-mac-lookup/?search_keywords=A1465

"Because there are eight MacBook Air models that match the A1465 model

number, you may wish to lookup yours by EMC Number, Model ID, or Serial

Number for greater precision. MacBook Air "Core i5" 1.7 11" (Mid-2012)"


By using any of those identifiers, you can narrow the build model down, & know.

Good luck & happy computing!🐬🍄

Similar questions

7 replies
Question marked as Top-ranking reply

Jul 17, 2020 1:32 AM in response to juliacura

Were you able to give the SSD a proper format?


In order to install 'the Installer' on the internal SSD then

use it, that SSD requires the partition map to be APFS as

stated in the instruction, before it will see a supported OS.


When you click in the 'Base System' what does that show?

Were you able to use macOS Utilities to erase partitions &

then have Utilities write the APFS file system to the SSD?


If you have another Mac, what system does it use? If you

bought a quality replacement SSD of capable specs, and

had an external enclosure (correct to the idea) a macOS

can be installed on there; then test ran. What you get first

seems to be an installer. But it's not found the APFS base.


• File system formats available in Disk Utility on Mac - Apple Support

https://support.apple.com/guide/disk-utility/file-system-formats-available-in-disk-utility-dsku19ed921c/19.0/mac/10.15


The correct path to ready an 'installer' so it has place to run

is in these instructions; see APFS. The SSD may have issues.

However the direction you took it, did not resolve anything.


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

https://support.apple.com/guide/disk-utility/erase-and-reformat-a-storage-device-dskutl14079/19.0/mac/10.15


You may need to first 'correctly identify' the MacBook Air

because model A1465 isn't enough; Apple re-used those #.

[There were Eight build models - with MacBook/Air A1465.]


• Lookup Mac Specs By Serial Number, Order, Model & EMC, etc @ everymac.com

https://everymac.com/ultimate-mac-lookup/?search_keywords=A1465

"Because there are eight MacBook Air models that match the A1465 model

number, you may wish to lookup yours by EMC Number, Model ID, or Serial

Number for greater precision. MacBook Air "Core i5" 1.7 11" (Mid-2012)"


By using any of those identifiers, you can narrow the build model down, & know.

Good luck & happy computing!🐬🍄

Jul 16, 2020 6:37 PM in response to juliacura

Looks like your MacBook Air favors by performing full Erase and reinstall (from internet)

then, get an installer of the best compatible system for MB/Air; then wait for it to install.


• How to erase a disk for Mac - Apple Support

https://support.apple.com/en-us/HT208496


• How to reinstall macOS from macOS Recovery - Apple Support

https://support.apple.com/en-us/HT204904


After you download installer, it could take hours before it will actually start/run in macOS.

Be sure to Erase All volumes on the Hard Drive. (This, to return drive to a blank state.)


No mention was made about the former macOS inside MacBook/Air on tiny internal drive.


You may find a suitable quality examples with extra enclosure, (to re-purpose old SSD)

from online source such as those at OWC site. These can show MB/Air upgrade items.

At least 500GB SSD for upgrade; I've found 240GB SSD is OK, only if used with external.


Good luck & happy computing!🌞🌎

Jul 16, 2020 9:00 PM in response to K Shaffer

Hello, thanks for answering. Start the system with option + cmd + r, and the system booted with OS X Catalina. I tried to reinstall macOS, but the installer cannot find the disk. So I tried to format the disk using Disk Utility, but it fails to complete the process.

Output command diskutil eraseDisk HFS + disk22 / dev / disk22:

Started erase on disk22
Unmounting disk
Creating the partition map
[ \ 0%..10%..20%..30%..40%..50% . . . . . . . . . . . . . . . . . . . . . . ] 50.0%
Error: -69877 Couldn't open device


Output command diskutil list



Why are there so many disks listed? Should I try to format all of them?


Thanks again!


Jul 16, 2020 10:12 PM in response to juliacura

By Command-line/terminal is not the way to reinstall macOS.


This method of erasure of drive partitions is not satisfactory

nor is it practical. You should access clearing of all contents

by use of macOS Utility from internet Recovery. It should be

able to affect the hardware, from internet utilities.


Notably erase and then install:

Erase and reformat a storage device.


• Add, delete, or erase volumes in Disk Utility on Mac - Apple Support

https://support.apple.com/guide/disk-utility/add-erase-or-delete-apfs-volumes-dskua9e6a110/19.0/mac/10.15


You're viewing content of some of the created partitions in

macOS; there are several in later versions.. 10.13/10.14/10.15.+


The hardware should be addressed so the utility can wipe it

from the root level. That is is where a new partition map goes

after fully erasing the drive. The macOS will add back what it

needs; usually automatically, without manual interpretation.


"..Apple File System (APFS) allocates disk space on demand. When a single

APFS container (partition) has multiple volumes, the container’s free space

is shared and can be allocated to any of the individual volumes as needed.."


Also it may be good to assume the present storage drive inside

your Mac could be finished; done for, or kaput, etc. Time to play

the game at the level provided by Mac disk utilities, in live mode.


Good luck & happy trails!🎨🎯

Boot Question Mark. Unable to write to last block of the device

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