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alextoms Author

Level 1

8 points

Macbook pro 16inches 2019 fails to reinstall catalina on recovery mode after erasing hard drive, and T2 chip dissallows to boot from external drive

My MacBook Pro 2019, 16 inches, with a T2 security chip, systematically times out when trying to reinstall Catalina in recovery mode, after erasing the main drive. The T2 chip dissallows booting from external drive, when trying to create an offline bootable installer.

What I've done:

Enter recovery mode (boot with Command + R pressed)
Erased the hard drive to make a fresh installation of Catalina,
Started the reinstall Catalina utility, which fetches Catalina from Apple servers.
Everything goes smooth until 90% of the installation, when it times out. I've tried this many times, on different internet connections.
Made an external bootable drive with a Catalina offline installer I found using the Catalina Patcher software.
Pluged the external drive to the Macbook. Problem: the Macbook does not allow to boot from external drives because of the T2 chip.
Tried to change the permissions to be able to boot from the external drive through the "Startup Security Utility" app (in recovery mode), but it requests admin privileges, and there is no admin in the computer (as I erased the main drive in step 1), so I get the "No administrator was found" error.

Please help!

MacBook Pro 13”, macOS 10.14

Posted on Oct 11, 2020 7:57 AM

Top-ranking reply

HWTech

Level 9

60,284 points

Posted on Oct 11, 2020 1:04 PM

If you have access to another Mac, then you can try to "Restore" the T2 firmware.

https://support.apple.com/guide/apple-configurator-2/revive-or-restore-mac-firmware-apdebea5be51/mac

Try connecting the laptop directly to the router using an Ethernet Cable and a USB-C to Ethernet Adapter for a faster & more reliable network connection which will also avoid any possible WiFi issues.

If these things do not work, then you will need to take the laptop to an Apple Store or an Apple Authorized Service Provider for assistance and possible repair.

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4 replies

Top-ranking reply

HWTech

Level 9

60,284 points

Oct 11, 2020 1:04 PM in response to alextoms

If you have access to another Mac, then you can try to "Restore" the T2 firmware.

https://support.apple.com/guide/apple-configurator-2/revive-or-restore-mac-firmware-apdebea5be51/mac

If these things do not work, then you will need to take the laptop to an Apple Store or an Apple Authorized Service Provider for assistance and possible repair.

Oct 11, 2020 8:02 AM in response to alextoms

alextoms wrote:

1. My MacBook Pro 2019, 16 inches, with a T2 security chip, systematically times out when trying to reinstall Catalina in recovery mode, after erasing the main drive. The T2 chip dissallows booting from external drive, when trying to create an offline bootable installer.

What I've done:

Enter recovery mode (boot with Command + R pressed)

2. Erased the hard drive to make a fresh installation of Catalina,

3. Started the reinstall Catalina utility, which fetches Catalina from Apple servers.

4. Everything goes smooth until 90% of the installation, when it times out. I've tried this many times, on different internet connections.

5. Made an external bootable drive with a Catalina offline installer I found using the Catalina Patcher software.

6. Pluged the external drive to the Macbook. Problem: the Macbook does not allow to boot from external drives because of the T2 chip.

7. Tried to change the permissions to be able to boot from the external drive through the "Startup Security Utility" app (in recovery mode), but it requests admin privileges, and there is no admin in the computer (as I erased the main drive in step 1), so I get the "No administrator was found" error.