0

I have a newly acquired Mac Mini 2018 that cannot get out of reboot loops.

I’ve already formatted the drive using target disk mode and trying to install a fresh copy of Mojave. There is nothing to restore or backup at point. I’ve tried:

  1. resetting pram and nvram

doesn’t make any difference just reboot loops

  1. making a bootable usb using the Apple Mojave install image and terminal instructions

the usb can be read, I boot holding down Apple key. The option will be given to install Mojave, once I hit enter, it doesn’t take me to MacOS utilities, it reboots and continues to loop

  1. use internet recovery to install OS i can successfully enter internet recovery mode, hardliners Ethernet. the progress bar goes to the end in about 5 minutes and instead of entering the installation program, it gets into a reboot loop and will restart in internet recovery mode and start the process all over again

  2. hold down d during boot to get diagnostic mode

this doesn’t do anything. I don’t know if this is because the drive is clean. I can hold down Apple D and it will take me internet recovery and then restart loop.

  1. hold down shift during boot to safe mode.

this doesn’t work because there is no OS on the internal ssd

  1. install Mojave on an USB and hold down Apple to boot, I can get the drive to appear but hitting enter will just restart instead of trying to load the OS

any ideas? Is this computer a lemon?

Improve this question
2
  • Let's enable verbose boot to see what's going on during internet recovery. In addition to holding down CMD+R, also hold down the 'V' key (verbose boot = CMD+V). Then with a high speed camera record the console text on the screen and upload some screen caps here.
    – pion
    Commented Mar 16, 2021 at 0:19
  • 1) Command V takes me from white apple logo directly to the question mark and folder icon (because of no recovery partition and no OS?) 2) command r by itself takes me to internet recovery spinning globe then restart loop 3) command r+v will take me to question mark folder or spinning globe loop depending which is the last action I successfully completed : /
    – David
    Commented Mar 16, 2021 at 7:28

2 Answers 2

Reset to default
1

Wiping the entire internal storage may have been a bad idea, as it also contains the Recovery Partition, and some 'keys' used to authenticate Secure Boot. (Also note that by default, you can't boot to a USB external: you need to set the Secure Boot options to allow that.)

https://support.apple.com/en-gb/HT208198

Your best bet is to install it from another Mac using Target Disk Mode.

Improve this answer
0

I ended up finding a solution. For anyone else that runs into this problem, I used Apple Configurator 2, put the bricked Mac mini in DFU mode (I didn't know you could with MacOS products) and another Mac to revive or restore the computer. The computer will install BridgeOS which will get the computer back to a state where you can reinstall the OS. I believe in my situation, the security firmware was corrupted during a previous failed installation. More here:

https://support.apple.com/guide/apple-configurator-2/revive-or-restore-a-mac-with-apple-silicon-apdd5f3c75ad/mac

Improve this answer

You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .