99% of the time that is a failing hard drive.
That was my initial take but since then it has exhibited similar problems booting from an external drive, so I am afraid it is the logic board. The SSD keeps appearing and disappearing. It appears to work until the mini gets thoroughly warmed up and then... I had hoped it was the SSD so I could repurpose the mini to replace a much older and slower mini I use as a server, but if it is the logic board that is a no go option. In the meantime I just ordered a 13†MacBook Pro from
Small Dog that I can use close cover with my 27†Thunderbolt monitor and full size wireless keyboard and trackpad. Until it arrives I still have my 12†iPad Pro that I am using now.
