How can I restore my 2011 21.5" iMac from my 2019 27" iMac?

[Mike Moore Studios]

I screwed something up trying to clean up my old 2011 21.5" iMac. It is now gutted and without an OS. I can't get it to load the Lion boot disk I'd made and internet restore isn't working either (seems to be a common problem). I have a 2019 27" iMac running Catalina. The hardware tests say the 2011 is ok, so I don't think that's a problem. Can I get the 2011 running from the 2019? How? Help me Obi Wan(s).



I also have a 2012 MacBook Pro running Mojave that I could use.

 

[Mike Moore Studios]

*Addendum....

I have Time Machine back ups of the 2 working machines I mentioned.

 

[USB3foriMac]

You have so many options to do that.
Easiest is "internet recovery".
You can also just run one of the time machine backups.
You could also download a high sierra installer on your newer machine.
There are more options, but I think that should suffice.

 

[Mike Moore Studios]

Thanks. After a brief bout of "oh f*** now what?!?!", got it sorted out.

The internet recovery didn't work, kept trying to load Lion, then saying basically that it couldn't. (As chronicled in this thread by others https://forums.macrumors.com/thread...nts-needed-to-install-mac-os-x.2230860/page-4).

Time Machine restore didn't work, said it wouldn't restore from a back up made by another machine (the 2012 MacBook Pro)

The 2019 iMac running Catalina wouldn't let me make a High Sierra installer.

FINALLY - Made a High Sierra boot thumb drive with the 2012 MacBook Pro finally that worked like a charm...BUT...NEEDED TO DISABLE WIFI FOR IT TO WORK.