I have a Mac Mini 2012 Server which has Ubuntu running on it. The issue I have is that I cannot seem to get it to boot from USB at this point in order to reinstall MacOS. Holding down Alt/Option seems to make a keyboard light blink and it waits until I let go. It then promptly boots Ubuntu again. I try Ctrl/Command+R and it boots to Ubuntu again. Same with CTRL+Shift+R.

I’m guessing the blinking light is the Mac saying it cannot find the recovery partition. Which I get... they were brand new drives right out of the box. The thing I’m confused about is that it is not giving me any option to boot from USB.

I still have the old drives where one has a 500+ mb EFI partition and the other has a 200+ mb EFI partition. I’m guessing the recovery software is in this partitions. I’m just looking for some guidance on the way to re-install MacOS from USB.

Another interesting thing was that I ran efibootmgr and there are references to a location from the Mac drive. One points to a file... the next points to the partition that file is in. Then there are two that are similar to MacOS but if not have that label. It’s my first time looking at this so I’m not sure if I should expect to see an option in the boot list for USB.

Any help is appreciated.

  • Welcome to Ask Different :) Do you have access to another Mac?
    – Nimesh Neema
    Commented Sep 20, 2020 at 7:35
  • How do you know if you have a macOS Recovery volume to boot to? What does Ctrl/Command+R mean? I am guessing you want the key combination Command (⌘)-R. The keyboard combination CTRL+Shift+R does not do anything. What did you think this was suppose to do? Again, I am guessing you want either the key combination Option-Command (⌘)-R or Shift-Option-Command (⌘)-R. See the Apple website How to reinstall macOS from macOS Recovery for more details. Note: Some non-Apple keyboards will not work with these key combinations. Commented Sep 20, 2020 at 11:10
  • 1
    Also, do you know what was the latest version of macOS (OS X) installed on your Mac? I ask this because some of the key combinations given in my previous comment will not work, if the Mac only had older versions of macOS (OS X) installed. Commented Sep 20, 2020 at 11:20
  • Thank you. I do have access to another Mac @NimeshNeema.
    – pcapazzi
    Commented Sep 21, 2020 at 0:15
  • @DavidAnderson Thanks David. I had a standard keyboard hooked up and (as far as I recall) ALT (as Option) would bring up the boot selector (drives usually colored in yellow to choose from). I believe Control on a Windows keyboard is the same as Command on a Mac so I was using that. Command (or Control) + R should have brought up a recovery menu. So... to try to get internet recovery I used Ctrl+Alt+R.
    – pcapazzi
    Commented Sep 21, 2020 at 0:23

1 Answer 1


The keyboard light that was blinking helped. Searching for reason where that would happen said there was not enough power to the keyboard. The (non-Apple) keyboard was going through a KVM switch (which actually is powered). So I figured there is something it doesn't like about the keyboard.

After directly connecting an Apple keyboard to the Mac Mini I was able to start the recovery process.

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