Accidently deleted Macintosh HD on Disk Utility - now my mac won't start up

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Accidently deleted Macintosh HD on Disk Utility - now my mac won't start up

Earlier today I was trying to reset my Macbook Pro (2016 model on MacOS Big Sur) to sell and I deleted Macintosh HD from the Disk Utility software thinking that it would reset my mac to factory settings. Now my Mac can't start up and shows a folder with a question mark in it.

First Aid does not work for any of the internal options.

"Preboot", "Recovery" and "VM" are unmounted every time I go back in to Disk Utility.

First Aid for Internal > AppleAPFSMedia does not work and says I need to repair the startup volume by running First Aid from Recovery? Isn't that what I'm doing?

When I try re-install MacOS it only shows "Macintosh HD - Data" & "Update" and the installation always fails when reaching the end on either option.

Attached is a photo of my Internal disks on Disk Utility. I would appreciate any help, thank you in advance!

MacBook Pro

Posted on Dec 28, 2022 10:33 PM

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Answer 1

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mr-sir1 Author

Level 1

10 points

Jan 3, 2023 10:09 PM in response to HWTech

Hi there, thanks for your help! I now have two problems that I am asking for assistance with.

i deleted Macintosh HD - Data successfully. All other ones such as Preboot and VM etc, have also been removed too. Hopefully that was supposed to be the case

And when erasing the physical drive APPLE SSD AP05..., it does not actually erase, it creates a new disk under it which I named "Untitled" - and when trying to re-install MacOS onto this new disk (Untitled), it gives an error with the following message "An error occurred while preparing the installation. Try running this application again."

Any help is appreciated.

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Answer 2

HWTech

Level 9

60,464 points

Jan 5, 2023 6:26 AM in response to mr-sir1

The macOS "erase" feature works differently than with other operating systems. macOS always creates at least a single volume when erasing a drive. Unless you customize the name, the default name is "Untitled". The macOS default from the factory is "Macintosh HD".

Unfortunately the macOS error messages are very cryptic and many times have nothing to do with the actual problem. Since you appear to be trying to reinstall macOS 10.12 Sierra, the problem may the system date. You may need to change the system date to some time in 2017 in order for the install to proceed. Launch the Terminal app from the Utilities menu and run the following command to set the date & time to Jan. 2, 2017 @ 11:33am:

date  -u  0102113317

If there are no errors, quit the Terminal app and select the "Install macOS" option.

Before upgrading to a later OS (10.15+), make sure to you are happy with the drive/volume name since renaming it later doesn't always fully rename the co-volume macOS 10.15+ utilizes.

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Answer 3

HWTech

Level 9

60,464 points

Dec 29, 2022 5:56 PM in response to mr-sir1

Try deleting the "Macintosh HD - Data" volume as well...you may need to unmount it first. Then try selecting the physical SSD which is the item labeled "Apple SSD AP05...". However, since this item appears below the "AppleAPFSMedia" item, I'm not sure if it will work properly....I've seen this before and it was a bit tricky to get erased when this happened. You may even need to delete the "AppleAPFSMedia" item as well. Select the physical drive ("Apple SSD AP05....") and erase it as GUID partition and MacOS Extended (Journaled) since it appears you are booting into the macOS 10.12 installer from that screenshot.

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Answer 4

Dec 29, 2022 4:50 PM in response to mr-sir1

Hi mr-sir1,

Thanks for posting here in Apple Support Communities. Seeing the folder with the question mark means that your Mac no longer contains an operation system. Following these steps should help to resolve the issue you're facing. See: If your Mac starts up to a question mark

1. Press and hold the power button on your Mac for up to 10 seconds, until your Mac turns off.

2. Every Mac has a power button. On notebook computers that have Touch ID, press and hold Touch ID.

3. Use Disk Utility to repair your startup disk. Follow the steps for a Mac with an Intel processor.

4. If Disk Utility found no errors or repaired all errors, reinstall macOS.

5. If you still need help, please contact Apple Support.

Please follow these steps when trying to repair your disk: How to repair a Mac disk with Disk Utility

Cheers.

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Answer 5

mr-sir1 Author

Level 1

10 points

Jan 4, 2023 8:48 PM in response to HWTech

Hi there, thanks for your help! I now have two problems that I am asking for assistance with.

i deleted Macintosh HD - Data successfully. All other ones such as Preboot and VM etc, have also been removed too. Hopefully that was supposed to be the case

And when erasing the physical drive APPLE SSD AP05..., it does not actually erase, it creates a new disk under it which I named "Untitled" - and when trying to re-install MacOS onto this new disk (Untitled), it gives an error with the following message "An error occurred while preparing the installation. Try running this application again."

Any help is appreciated.

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Answer 6

allen_31

Level 2

325 points

Jan 3, 2023 10:48 PM in response to mr-sir1

Flashing folder with a question mark is an error that may occurs when Mac cannot detect its boot directory. This usually happens when:

1. Mac cannot find the startup Disk.

2. MacOS is corrupt

However, you can try the below methods to fix the issue:

1. Boot your Mac into macOS Recovery Mode

2. Repair startup disk using disk utility

3. Reinstall macOS

Further, to fix the issue, I suggest you to check the below link and follow the described methods:

https://www.stellarinfo.com/blog/repair-mac-flashing-question-mark-folder-error/

Hope it helps!

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Accidently deleted Macintosh HD on Disk Utility - now my mac won't start up

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