Despite our best efforts, sometimes a macOS update goes wrong, such as the power going out in the middle of the process. Other glitches can occur, including ones that are undiagnosable.
If your Intel Mac with a T2 security chip or any M1 Apple silicon Mac won’t start up normally or through recoveryOS, you can try to revive it by fixing the firmware inside these chips that handles aspects of security and startup management while preserving all your files. If that fails, you can opt to restore it, which wipes the machine clean, but will get it working again. Both processes are made for system administrators but can be used by anyone.
