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I need to factory reset a MackBook Pro.

Every time I start it up it takes ages to load and then I see this:

Your computer is disabled. Try again in 60 minutes.

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I tried to restart the Mac with CMD + R but it won't boot in repair mode.

Any alternative command?

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  • 1
    Is your computer managed by a MDM?
    – Nimesh Neema
    Jul 11, 2019 at 9:19
  • Yes @NimeshNeema, we manages computers through JAMF Jul 11, 2019 at 10:07

1 Answer 1

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The problem here is the firmware that loads the OS is trying to prevent brute force attempts to crack the password and too many wrong ones have been entered in a row. If you don’t want to seek Apple Service, supplying new EFI firmware may be one way forward. After days of works I found the solution here.

Here are the steps to fix the problem using a tool called refind

  1. Go here and download the refind tool to an USB flash drive
  2. Unzip the file
  3. Insert a USB stick into your Mac
  4. On a terminal run diskutil list and find your USB key (for me was /dev/disk2)
  5. Run diskutil unmountDisk /dev/disk2
  6. Run dd if=refind-flashdrive-0.11.4.img of=/dev/disk2 and in 1 minute you will have the rEFInd Boot Manager on your USB stick
  7. On another USB stick put MacOS Mojave following this guide.
  8. Now insert both USB Sticks on your Mac, fire it up and keep the button Option pressed down
  9. Now you will see 3 things: Your Mac HD (in my case was formatted), Mac Mojave USB installer and the rEFInd Boot Manager. Click on the rEFInd Boot Manager.

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  1. Choose the Gparted button and follow this guide step by step in order to create a GPT Partition Table with gdisk in EFI Mode

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  1. Now if you are back in the rEFInd Boot Manager is time to move the cursor to the Mac Mojave installation, press Tab or F2 and choose the option "Boot macOS in single user mode"
  2. A terminal will open and you need to enter these commands in succession:
nvram -c

nvram -xp

nvram -c

nvram -c

nvram -c

nvram -c

nvram -xp

Yes you need to clear the nvram several times in a row! (nvram -xp just lists what is in nvram) Then type in exit and wait.

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The laptop should continue booting in that command window until it switches over to the GUI window and you end up at the general OS Installer window.

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