Looking for assistance reinstalling Mac OS on a ~2012 iMac

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Level 1

4 points

Looking for assistance reinstalling Mac OS on a ~2012 iMac

I cleared the disk utility on my dad's old iMac and now I'm struggling to get a new OS installed on it. So far I've tried the following:

When I try to install the OS through masOS Utilities I get the following error "The recovery server couldn't be contacted"
- I made sure I was connected to wifi
- I also opened terminal and ran a prompt to ensure the date/time is correct
I've tried Recovery mode (Command + R upon opening the computer) and selected the Recovery disk option but it never loads. I just get a white screen with the Apple logo
- I've also tried (Option key only upon opening the computer) and had no luck
I've tried Internet Recovery mode (Option/Alt + Command + R upon opening the computer). After connecting to wifi the globe spins for a while and then I get the following error: -21 06F
I've tried opening in Safety Mode but the computer never actually puts up when I try this method. I get the loading bar under the Apple logo and even when it goes to completion it never transitions from that page
I've reset my PRAM/NVRAM using (Command + Option + P + R) and no luck

Currently the iMac simply opens and will load indefinitely but has no working OS so its a desk ornament for now. Everything has been transferred over and my dad has a new iMac but I'm trying to see if I can salvage this one so curious to see if anyone has any suggestions on how I can proceed. I also can't locate the original CDs that came with this iMac so I can't install the OS using that route if that is even possible.

iPhone 14 Pro, iOS 16

Posted on Nov 17, 2023 4:16 PM

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Answer 1

Best reply

padams35

Level 4

3,313 points

Nov 18, 2023 12:14 PM in response to Mansoor_K

MacOS Mojave - Turn the iMac into a dedicated system for running whatever legacy 32-bit intel applications fill you with nostalgia.

MacOS Catalina - Slightly newer with slightly better modern software support at cost of being 64-bit only.

MacOS Sierra - Uses the older HFS+ file system by default which plays nicer with old HDDs than the new APFS format. Good if your model has the 1TB HDD and you don't want to spend money on an SSD upgrade, internal or external.

Linux - If you can't get a MacOS installer from a friend or Apple store genius bar or if you want ongoing security updates. Fedora is good non-demanding home-office productivity focused distro, while Mint is a user friendly general purpose distro just to name two.

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Answer 2

padams35

Level 4

3,313 points

Nov 17, 2023 7:26 PM in response to Mansoor_K

Internet recovery is sometimes finicky on older macs trying to reinstall older OS versions.

Do you have access to a 2019 or older Mac?

If so you can create a bootable USB installer. Create a bootable installer for macOS - Apple Support

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Answer 3

Mansoor_K Author

Level 1

4 points

Nov 18, 2023 8:05 AM in response to padams35

Thanks for the information! If I can't get access to a 2019 or older mac is there an alternative? Additionally, is there a recommended OS version I should look to use when creating the bootable installer?

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Answer 4

Mansoor_K Author

Level 1

4 points

Nov 18, 2023 5:23 PM in response to padams35

Thanks again for all of the help so far. I was able to use my 2015 Macbook to get a bootable USB installer. I installed High Sierra currently and loaded this into my iMac. I held the option key, booted into Recovery mode, connected to wifi, and selected the High Sierra installer that was now present but I'm again stuck looking at a white screen with an Apple logo and no loading screen/bar. Did I miss a step or should I use an older version than High Sierra and see if that changes things? Currently I plan to let this run all night to see if somehow runs overnight.

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Answer 5

padams35

Level 4

3,313 points

Nov 19, 2023 7:30 AM in response to Mansoor_K

You were supposed to to select the USB installer after holding option key, not Recovery mode.

It sounds like you booted into the same recovery mode that was giving you problems and then selected the USB stick as the target drive to install MacOS onto.

If the recovery process got far enough to erase and reformat the USB stick you may need to remake the USB installer. If not go back to option key boot and select the USB installer instead of recovery mode.

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Answer 6

Mansoor_K Author

Level 1

4 points

Nov 22, 2023 3:38 PM in response to Mansoor_K

Following back up on this as I appear to have "broken" it again. I kept updating and I may have gone too far so I attempted to go back to Sierra. I remade a USB drive to lower the OS back and I seem to have once again removed the original drive but this time nothing even shows up when I hold down the options key.

I plug in the USB, start the computer and hold option, select the USB drive that has Sierra on it, connect to wifi, and then I'm again greeted with the white screen and Apple logo with no progress bar. Any recommendations on how I can pick up from here to get it back to working?

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Answer 7

Mansoor_K Author

Level 1

4 points

Nov 19, 2023 8:21 AM in response to padams35

I was able to get it working this morning using Sierra! Thanks again for all the help. I've marked your previous answer as the best answer. Have a great day!

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