Hi everyone,
Thanks for you input. It took about 3 hours of work, partly because 1) the Old Mini (a late model 2015) just crawled when hooked up to the 4K screen, and it would take a minute or two for even System Preferences to open up. 2) I forgot to factor in that I only have one monitor for both the Old Mini and the New Mini (i.e., the 4K TV).
I ended up having the following experiences:
- I had to resort to disconnecting the New Mini from the 4K TV and reconnecting the Old Mini so I could have a screen to work with on the Old Mini.
- Apparently Catalina has a security setting which doesn’t allow a Mac to go into target disk mode until the default security setting in System Preference is changed to allow target disk mode. That took a YouTube video to figure out.
- Once I got the Old Mini into target disk mode, and after connecting it to a 2019 iMac (via USB on the Old Mini to Thunderbolt 3 cable on the iMac), the iMac never recognized the Old Mini as an external driven target disk mode. Rebooting both the iMac and Old Mini didn’t seem to help at all. And after three attempts, I gave up on this approach.
- So I created an external bootable USB drive on the iMac.
- Once again, I reconnected the Old Mini to the 4K TV
- It took about three attempts, but eventually, I was able to get the Old Mini to boot into recovery mode. Once in recovery mode, I was able to erase the Old Mini hard drive, and re-install Mac OS Catalina off the external USB drive.
- And to top off the problems, once I reconnected the New Mini to the 4K TV and peripherals, it also had troubles re-recognizing the bluetooth keyboard again. It took about 4 attempts to get the New Mini to reboot into recovery mode that allowed me to get to a screen that would allow me to reconnect the bluetooth keyboard.
- Total time - about 3 hours
Whew!
Lastly one other lesson learned -- when doing a trade-in for a Mini, Apple is supposed to send a “trade-in kit” (shipping box and shipping labels). But Apple screwed up and sent a shipping box meant for a laptop, which of course, the Old Mini did not fit into. Fortunately, I still had the New Mini shipping box and used that to ship the Old Mini back to Apple for my trade-in.
Anyway, thanks again for everyone’s help. Now I’m just glad to be able to return the Old Mini for my trade-in and enjoy the much faster speeds of the New Mini.
