In rare cases, such as a power failure during a macOS update or upgrade, the Mac may become unresponsive, so the firmware must be repaired or restored.
【Important】Try repairing your computer first. If the repair fails or you cannot start your Mac from the startup volume, recoveryOS, or Internet Recovery, you must restore the firmware and erase the internal flash memory.
What does Repair do on Mac?
The fix is to update the firmware on the Apple T2 Security Chip. Repair is intended to make no changes to the startup volume, the user's data volume, or any other volumes. User data may be preserved (if recoverable).
What does recovery do for Mac?
Recovery means updating the firmware and erasing recoveryOS and macOS on the internal storage. After this process is complete, all data on any internal volumes will be irrecoverable.
You must restore the firmware and erase the internal flash memory if:
Repair firmware failed
Can't start Mac from startup volume, recoveryOS, or Internet Recovery
before the start
These repair and recovery instructions concern the following Intel-based Mac computers with the Apple T2 Security Chip:
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iMac (2020)
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Mac Pro (2019)
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Mac mini (2018)
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iMac Pro (2017)
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MacBook Pro (13-inch, 2020, four Thunderbolt 3 ports)
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MacBook Pro (13-inch, 2020, two Thunderbolt 3 ports)
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MacBook Pro (13-inch, 2019, four Thunderbolt 3 ports)
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MacBook Pro (13-inch, 2019, two Thunderbolt 3 ports)
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MacBook Pro (13-inch, 2018, four Thunderbolt 3 ports)
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MacBook Pro (16-inch, 2019)
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MacBook Pro (15-inch, 2019)
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MacBook Pro (15-inch, 2018)
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MacBook Air (Retina, 13-inch, 2020)
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MacBook Air (Retina, 13-inch, 2019)
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MacBook Air (Retina, 13-inch, 2018)
Make sure you have:
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The latest version of Apple Configurator 2 installed on a Mac running macOS 10.15.6 or later
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internet access
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You may need to configure your network proxy or firewall ports to allow all network traffic from Apple devices into Apple's network 17.0.0.0/8. For more information on the ports used by Apple products, see the Apple Support article Using Apple Products on a Corporate Network. For more information on whether your network uses a web proxy or firewall, please refer to your router manual or consult your internet provider.
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A supported USB-C to USB-C charging cable (as sold by Apple, not available in all countries or regions) or a supported USB-A to USB-C cable
The USB-C cable must support power and data. Thunderbolt 3 cables are not supported.
How the Repair and Recovery Process Works
The repair and recovery process consists of the following steps:
Step 1: Connect your Macs with a supported USB-C cable, find Apple Configurator 2 in the Applications folder or Launchpad on the first Mac, and launch Apple Configurator 2.
Step 2: Restart the second Mac using a special key sequence. The keys vary depending on the type of Mac you are repairing or restoring.
Step 3: Repair your Mac using Apple Configurator 2.
Step 4: If the repair fails, you can use Apple Configurator 2 to restore the Mac.
Step 1: Connect Mac Computer
1. Make sure your first Mac is plugged in and turned on.
[Important] Start Apple Configurator 2 after connecting the two Mac computers with a USB-C cable.
2. Plug in the USB-C cable (with any adapters needed) and connect the two Macs.
Step 2: Prepare Your Mac for Repair or Restoration
Choose the Mac you want to repair or restore.
If repairing or restoring an iMac (2020) or iMac Pro (2017):
1. Disconnect the iMac Pro or iMac from the power source.
2. Plug the USB-C cable into the Thunderbolt port closest to the Ethernet port.
The back of an iMac Pro (2017), showing the four Thunderbolt 3 (USB-C) ports, with the rightmost port labeled.
Back of an Intel-based iMac (2020), showing two Thunderbolt 3 (USB-C) ports, with the rightmost port labeled.
3. While holding down the power button, connect the iMac Pro or iMac to a power source and continue to hold the power button for about 3 seconds.
Note: There will be no screen activity on the iMac Pro or iMac that you are trying to repair or restore.
If repairing or restoring a Mac mini (2018):
1. Connect a monitor to your Mac mini (so you can see when the restore process is complete).
2. Unplug the Mac mini from its power source for at least 10 seconds.
3. Plug the USB-C cable into the Thunderbolt port closest to the HDMI port.
The back of the Intel-based Mac mini with the Apple T2 Security Chip showing an expanded view of the four Thunderbolt 3 (USB-C) ports, with the rightmost port labeled.
4. While holding down the power button, connect your Mac mini to a power source and continue to hold the power button for about 3 seconds.
Note: There will be no screen activity on the Mac mini you are trying to repair or restore.
If repairing or restoring an Intel-based Apple laptop:
1. Press the Sleep/Wake button for approximately 5 seconds to shut down the Apple Notebook.
2. Plug the USB-C cable into the front Thunderbolt port on the left side of the Apple laptop.
The left side of an Intel-based MacBook Pro with the Apple T2 Security Chip, showing the two rear Thunderbolt 3 (USB-C) ports, with the rightmost port labeled.
The left side of an Intel-based MacBook Air with the Apple T2 Security Chip, showing the two rear Thunderbolt 3 (USB-C) ports, with the rightmost port labeled.
3. While holding down the power button, press all three of the following keys for about 3 seconds:
Right Shift key
Left Option key
Left Control key
Note: There will be no screen activity on the Apple laptop you are trying to repair or restore.
If repairing or restoring a Mac Pro (2019):
Your Mac Pro's firmware needs to be repaired if the light turns amber and blinks in the following sequence within 4 seconds: three short blinks, three long blinks, then three short blinks. For more information, see the Apple Support article: Mac Pro (2019) status light behavior.
1. Connect a monitor to your Mac Pro (so you can see when the restore process is complete).
2. Disconnect your Mac Pro from power, then do one of the following:
- For a desktop Mac Pro, plug the USB-C cable into the Thunderbolt port furthest from the power button.
Back of Mac Pro (2019), showing two Thunderbolt (USB-C) ports, with the port furthest from the power button marked.
For a rackmount Mac Pro, plug the USB-C cable into the Thunderbolt port closest to the power button.
Back of Mac Pro (Rackmount, 2019), showing two Thunderbolt (USB-C) ports, with the rightmost port labeled.
3. While holding down the power button, connect the Mac Pro to a power source and continue to hold the power button for about 3 seconds.
Note: There will be no screen activity on the Mac Pro you are trying to repair or restore.
Step 3: Fix the firmware
1. In the Apple Configurator 2 window on the first Mac, select the DFU icon for the Mac whose chip firmware you want to repair.
Apple Configurator 2 showing the Mac with Repair Device selected in the pop-up menu.
2. Do one of the following:
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Choose Actions > Advanced > Repair Device, then click Repair.
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Control-click the selected DFU icon and choose Advanced > Repair Device, then click Repair.
Note: If any Mac dies during the process, start the repair process again.
3. Please wait for the process to complete. During this process, the Apple logo on the second Mac will appear and disappear.
4. After the repair process is successfully completed, the Mac will restart.
Note: If the repair fails, proceed to step 4.
5. If necessary, use recoveryOS to reinstall macOS.
6. Quit Apple Configurator 2 on the first Mac, then unplug any cables and adapters.
Step 4: Restore the firmware and erase all data
1. In the Apple Configurator 2 window on the first Mac, select the DFU icon for the Mac you want to restore.
2. Do one of the following:
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Choose Actions > Restore, then click Restore.
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Control-click the selected DFU icon and choose Actions > Restore, then click Restore.
Note: If any Mac dies during the process, start the restore process again.
3. Wait for the process to complete. During this process, the Apple logo on the second Mac will appear and disappear.
4. After the restoration process is complete, your Mac will restart.
5. After restarting your Mac, press Shift-Option-Command-R at startup (Internet Recovery) to install the macOS that came with your Mac, or the closest version still available.
6. Quit Apple Configurator 2 and unplug any converters and cables.