1. Download Apple Configurator:
    Visit the App Store and download Apple Configurator.
  2. Enter DFU Mode:
    1. Unplug the power cable.
    2. While holding the power button, plug in the power cable.
    3. Wait for 10 seconds, then release the power button to enter DFU mode.
  3. Restore the DFU Device
    1. Manually download the latest firmware image from
      this link
    2. Drag the IPSW file onto the DFU icon.
  4. Troubleshoot Connection Issues:
    1. If you encounter error codes such as “Error 21” or codes starting with “4xxx”, it might be a connection issue.
    2. Try using a different cable, switching to another Mac, or running macOS in a virtual machine on Windows.
    3. Remove the SSD and reconnect it securely.

Note: When using an M4 Mac Mini, please use the middle port at the back marked with a Thunderbolt icon.

Additionally, Thunderbolt 3  cables are not supported.