(T2 chip) Restore Mac desktops in Apple Configurator
This task covers the following Apple desktop computers:
iMac Pro
Mac mini (2018)
In very rare circumstances, such as a power failure during a macOS upgrade, an Apple desktop computer that has the Apple T2 Security Chip may become unresponsive and so the firmware on that chip must be restored. To perform that restore, you must have:
Apple Configurator 2.6 or later installed on any Mac that supports macOS 10.13.2 or later and has Internet access.
You may need to configure your web proxy or firewall ports to allow all network traffic from Apple devices to Apple’s network 17.0.0.0/8.
Supported USB-A or USB-C to USB-C or a Thunderbolt cable, such as the one sold by Apple (may not available in all countries or regions).
The USB-C cable:
Must support both power and data.
Can be used in conjunction with a supported Thunderbolt to USB-C adapter, such as the one sold by Apple (may not available in all countries or regions).
Set up the Mac with Apple Configurator 2 for restoring the firmware on the Apple T2 Security Chip
Verify that:
You have the latest versions of macOS 10.13 or later and Apple Configurator 2
The Mac is plugged into a power source
You can connect to the Internet
If necessary, quit iTunes, launch Apple Configurator 2.6 or later, then plug in (along with any adapters needed) the USB or Thunderbolt cable.
Prepare the iMac Pro for the Apple T2 Security Chip firmware restore
Disconnect the iMac Pro from power.
Plug the cable into the Thunderbolt port closest to the Ethernet port.
While holding down the power button, connect the iMac Pro to power and continue to hold the power button for about 3 seconds.
Note: You won’t see any screen activity from the iMac Pro.
Prepare the Mac mini for the Apple T2 Security Chip firmware restore
Plug in a monitor so you can see when the process is complete.
Disconnect the Mac mini from power.
Plug the cable into the Thunderbolt port closest to the HDMI port.
While holding down the power button, connect the Mac mini to power and continue to hold the power button for about 3 seconds.
Note: You won’t see any screen activity from the Mac mini.
Use Apple Configurator 2 to restore the firmware on the Apple T2 Security Chip.
In Apple Configurator 2
on your Mac, select the device in the device browser.
Choose Actions > Restore, then click Restore.
Note: If you lose power to either Mac during this process, begin the restore process again.
Wait for the process to complete. During this process, an Apple logo will appear and disappear.
After the process completes, your Apple desktop computer will reboot.
Important: When you restore the firmware on the Apple T2 Security Chip, you must verify that the restoration was successful because Apple Configurator 2 may not alert you.
Quit Apple Configurator 2 and unplug any adapters and cables.