Dfu Revive

– Source: Apple Support. Experimenting can sometimes lead to issues. That’s exactly what happened to me after a failed macOS installation, which resulted in a big question mark with a prompt to visit the Mac restore page. For some years now, when a Mac is unable to boot macOS and cannot even run macOS Recovery to repair or reinstall the OS, the only way to bring it back to life is to enable DFU Mode (Device Firmware Upgrade). This mode is stored in ROM and cannot be erased under any circumstances.1