How to revive or restore Mac firmware

Rarely, a Mac with Apple silicon or the Apple T2 Security Chip might stop responding and need its firmware to be revived or restored by another Mac.

• When to revive or restore

• What you need to revive or restore

• How to prepare a laptop to revive or restore

• How to prepare a desktop computer to revive or restore

• How to revive or restore

When to revive or restore

If the firmware stored in its memory needs to be revived or restored, a Mac with Apple silicon or the Apple T2 Security Chip might become unresponsive. This can occur in certain rare circumstances, such as when a power failure interrupts macOS installation. Symptoms can include:

• Starts up to an exclamation point in a circle

• Shows the status indicator light pattern for firmware recovery mode

• Turns on, but starts up to a blank screen (there are also other causes and solutions for a blank screen)

Reviving or restoring firmware might also help if your Mac experiences a persistent macOS installation error not resolved by other solutions for macOS installation errors.

What you need to revive or restore

1. The affected Mac, which is the Mac with Apple silicon or Mac with the Apple T2 Security Chip that you're reviving or restoring. Other Mac models don't apply.

2. Another Mac of any model using macOS Sonoma 14 or later. You will use this Mac to revive or restore the affected Mac. Find out which macOS your Mac is using.

3. A USB-C to USB-C cable that supports data and charging, such as the Apple USB-C Charge Cable included with some Apple products. It works with ports on Mac that accept a type USB-C connector. Don't use a Thunderbolt 3cable.

How to prepare a laptop to revive or restore

You will use the USB-C cable to connect the two computers, then enter DFU (device firmware update) mode on the affected computer.

1. Make sure that both computers are connected to power.

2. On the affected MacBook Pro or MacBook Air, plug the USB-C cable into the DFU port. Learn how to identify the DFU port.

3. On the other Mac:

   • Plug the other end of the USB-C cable into any USB-C port.

   • Make sure that this Mac is turned on and connected to the internet.*

4. On the affected Mac, enter DFU mode:

   1. Press and hold the power (Touch ID) button for up to 10 seconds, until the Mac turns off. If the Mac turns on instead, repeat this step.

   2. Press and release the power button, then immediately press and hold all four of these together on the built-in keyboard:

      • Control ⌃ on the left side of the keyboard

      • Option ⌥ on the left side of the keyboard

      • Shift ⇧ on the right side of the keyboard

      • Power button

        

   3. Mac laptop with Apple silicon: Keep holding all four keys for about 10 seconds, then release all keys except the power button. Keep holding the power button for up to 10 more seconds—until the other Mac shows a DFU window in the Finder. If it first shows an alert asking you to allow the accessory to connect, release the power button and click Allow.

   4. Mac laptop with T2 chip: Keep holding all four keys for about 3 seconds—until the other Mac shows a DFU window in the Finder. If it first shows an alert asking you to allow the accessory to connect, release all keys and click Allow.

5. The affected Mac is now in DFU mode and should show a blank screen. Follow the below steps to revive or restore.

How to prepare a desktop computer to revive or restore

You will use the USB-C cable to connect the two computers, then enter DFU (device firmware update) mode on the affected computer.

1. On the affected Mac, plug the USB-C cable into the DFU port. Learn how to identify the DFU port.

2. On the other Mac:

   • Plug the other end of the USB-C cable into any USB-C port.

   • Make sure that this Mac is turned on and connected to power and the internet.*

3. On the affected Mac, enter DFU mode:

   1. Unplug the Mac from power.

   2. Press and hold the power button.

   3. Keep holding the power button while plugging the Mac into power, and continue holding it for up to 10 seconds—until the other Mac shows a DFU window in the Finder. If it first shows an alert asking you to allow the accessory to connect, release the power button and click Allow.

4. The affected Mac is now in DFU mode and should show a blank screen. Follow the below steps to revive or restore.

How to revive or restore

After preparing your computers as described above, the Finder on the other Mac should show a DFU window, with Mac selected in the sidebar and "Mac DFU Mode" on the right. Don't see it?

Revive

Try reviving first. It can be faster than restoring, and it doesn't erase your Mac.

1. From the DFU window in the Finder, click Revive Mac. Then click Continue to confirm.

2. A progress bar in this window shows that the revive is underway. When the revive is complete, the affected Mac restarts automatically. If it shuts down instead, press the power button to turn it on.

3. If asked, select the volume to recover (such as Macintosh HD), then click Next.

4. If asked, select a user you know the password for, and enter that user's login password. Click Next, then click Restart.

5. If reviving a Mac with Apple silicon, the revived Mac might load startup options, showing your startup disk (such as Macintosh HD) and Options with a gear icon. Select your startup disk, then click the Continue button that appears below it.

6. The revived Mac finishes starting up and the process is complete.

Restore

Try reviving your Mac first. If your Mac can't be revived, follow these steps to erase it and restore it to factory settings.

1. From the DFU window in the Finder, click Restore Mac. Then click Restore and Update to confirm.

2. A progress bar in this window shows that the restore is underway. When the restore is complete, the affected Mac restarts automatically. If it shuts down instead, press the power button to turn it on.

3. If asked, select a Wi-Fi network or attach a network cable.

4. Mac with Apple silicon:

   1. If asked, sign in to the Apple Account previously used with this Mac.

   2. When the setup assistant opens, use it to finish setting up your Mac.

5. Mac with T2 chip:

   1. The restored Mac shows a spinning globe as it starts up from macOS Recovery over the internet. Choose your language when asked.

   2. If asked, sign in to the Apple Account previously used with this Mac. Then click Exit to Recovery.

   3. When you see the list of utilities in Recovery, choose the option to install or reinstall macOS.

   4. After macOS installation, the Mac restarts and opens the setup assistant. Use it to finish setting up your Mac.

If you don't see a DFU window in the Finder

After preparing your computers to revive or restore, if you don’t see the DFU window in the Finder, try these solutions:

• Choose Finder > Settings from the menu bar. Click Sidebar at the top of the settings window, then confirm that "CDs, DVDs, and iOS Devices" is selected.

• Look for “Mac” in the Locations section of the sidebar of any Finder window. Select it, if present.

• Disconnect the USB-C cable from the affected Mac, then press and hold the power button for up to 10 seconds to turn off the affected Mac. Reconnect the USB-C cable to the DFU port, then try again to enter DFU mode. Proper timing of key presses is important.

• Try a different USB-C cable. It must support both data and charging.

If you can't complete a revive or restore or you need help, contact Apple Support.