If you are able to repair you drive, then you will need to be running at least Sierra in order to mount the macOS partition on the SSD via USB.
Below are two possible solutions.
Using a Third Party Tool
Since you already have the SSD connected as disk2 in a USB port, a simple solution would be to download and use gdisk.
The current gdisk installer is ...
You need to take it to an Apple Store. The SecureBoot settings can't be changed unless there is a valid admin user, so you can't boot to an external. Recovery is your only other option, and that's not working.
I had a similar issue with my 2018 Mini: I had to run the "Welcome to Mac" routine and create a new user before I could alter SecureBoot, even though ...
It looks like the Macbook model is disabled in JAMF or a firmware password is in place. We don't know your MDM and client security configuration.
I rather recommend you to ask this JAMF specific question in the official JAMF Forum.
So lets see if I have this right... if you shut it down it turns back on no problem. If it goes to sleep it takes 5 days to turn back on.
Just a suggestion... what if you turn off sleep in System Preferences -> Energy Saver? I'm interested if it does the same thing if it stays on but just goes dead.
I would also try a fresh OS install either from a ...
I'm assuming you've disabled SecureBoot, and that the volume name is identical in what follows:
It's possible that the T2 chip on these new (2018) Minis makes 'straight' cloning difficult.
I had the same problem when I cloned my old 2012 Mini's volume onto my 2018 Mini : I too got a flashing question mark. I was able to fix it by installing Mojave on top ...
By default, rEFInd is installed in the EFI partition. Another option is to install rEFInd in a new small "Mac OS Extended (Journaled)" volume. This will allow rEFInd to appear in the Startup Manager.
Below are the steps. The commands need to be entered into a Terminal application window.
Create the new volume. The diskutil command, shrinks the APFS ...
From Ubuntu, you need to run the command gdisk.
Open a Terminal. Basically, press the control+alt/option key combination.
Enter the command given below to execute gdisk.
sudo gdisk /dev/sda
If the version is not at least 1.0.4, then enter the q command to exit gdisk. Next, enter the commands given below to update gdisk, then return to step 2. Otherwise, ...
I finally put my iMac together again with new/refurbished logic board.
I'm an idiot so I managed to bend the CPU and lots of socket pins...(because it's kinda tricky getting heatsink on and connecting plate underneath without thermal paste attaching CPU to heatsink and shifting it out of proper alignment..
So this meant no boot - but then tried again ...
I found this issue with the touchbar not showing anything happens only if you've file vault on.
After booting my system I just assumed it was at the login screen and asking for password. After entering the password it logged me in and the touchbar controls appeared again.