how do I restore a Mac Mini late 2014 to initial condition?
I want to donate it without any trace of my own data and settings. It is currently running MacOS 12.7.6
iPhone 12, iOS 15
Question marked as
Does your Mini have an internal hard drive or SSD? Or both with a Fusion Drive setup?
If it has just an internal SSD, then the instructions provided by @Niel is sufficient.
If, however, the Mini has an internal hard drive (even if part of a Fusion Drive setup), then you will need to write zeroes to the whole physical hard drive to completely destroy all traces of data on that hard drive, or enable Filevault on the Fusion Drive to encrypt the data.
Before doing that , you should make a bootable macOS 12.x USB installer using the instructions in the following Apple article:
Create a bootable installer for macOS - Apple Support
The simplest way forward would be to first enable Filevault and let the encryption process complete (it could take a day or two assuming the drive is healthy....more if the hard drive is worn out or failing). Once Filevault encryption has completed, then you can follow the instructions in the Apple article @Niel provided to erase the Fusion Drive (no need to provide a password to unlock the Fusion Drive). These special instructions I have presented are not necessary if the Mini only contains an internal SSD since SSDs work differently from hard drives.
