Erasing iMac failed and can’t get it to now boot.

Question

Erasing iMac failed and can’t get it to now boot.

I have a 2020 iMac with an APFS drive that had multiple accounts, all connected to iCloud. The iMac was running super slow so I attempted to wipe it using Disk Utility. I didn’t sign out of any iCloud accounts (which I read may have been an/the issue) but rather simply ran the Disk Utility Erase function, kept the formatting as APFS and then attempted to reinstall a clean OS Ventura (which was the OS on the iMac) via recovery mode. That failed and I received a S.M.A.R.T. error.

I then attempted to reboot into recovery again and this time (and each other time) I’m in an old Internet Recovery mode. I again tried to erase the hard drive but this time only saw MacOS Journaled (not APFS) as an option, which then split my hard drive as pictured into a SSD AND HHD. I then tried again to reinstall a clean OS but this time the option was Sierra, which again failed.

It also appears that despite erasing the drive, I still see it show in some views that roughly 1 TB (of the 3 TB drive) is still used, so I’m guessing maybe it’s not fully erased and/or that maybe me not signing out of the iCloud accounts froze if.

Fortunately I back everything up, but I’d really like to fix it and the drive no longer shows any errors. Rather can’t boot up and can’t install a new OS. I’m not sure what is next best or possible. Do I somehow create a thumb drive OS that I can run to fix things? Do I something in Terminal? Something else or is the computer now basically shot?

Any help would be much appreciated for a guy who doesn’t really know what to do next.

iMac (2017 – 2020)

Posted on Nov 14, 2024 11:53 AM

Reply

Answer 1

den.thed

Level 10

82,468 points

Nov 15, 2024 4:04 PM in response to antoniofrombakersfield

antoniofrombakersfield wrote:

Thanks for getting back with me and sorry my slow response. In short Disk Utility couldn’t fix it and given I now know it’s 7 years old I’ve decided to get a new Mac Mini (but curious if you have a good 27” and/or 32” non-Apple monitor recommendation as I can’t do Apple prices).

Most any aftermarket LG, Samsung, HP, etc... monitor will work with the Mac mini.

see > Connect a display to Mac mini - Apple Support

But I’ve also decided I want to try to “fix” it and see what happens. I found this thread on Reddit and it seems to be exactly my issue. Basically a SMART warning (not really an error) is preventing the new OS install. So the recommendation is Terminal for OS install but as you’ll see from the pics below it can’t find my USB Installer. Any ideas?

The bad internal drive needs to be replaced before you can move ahead and install a macOS. Sadly Apple Stores will not work on older Mac's and so you will need to find an independent AASP that is willing to replace the bad internal drive or DIY.

Another option is to get and use an external SSD to startup and run the 2017 iMac from.

see > Use an external SSD as your startup disk … - Apple Community

Not really sure what the image on and of the Apple laptop has to do with the 2017 iMac...?

If you are trying to create an installer, see > Create a bootable installer for macOS - Apple Support

Reply

Answer 2

den.thed

Level 10

82,468 points

Nov 15, 2024 7:25 AM in response to antoniofrombakersfield

Sorry for not getting back to you last night.

1) The iMac's Fusion drive is now formatted APFS which is what is needed to install Ventura.

2) Try running Disk Utility First Aid Repair a couple more times while in Recovery Mode to see if that helps.

3) If not, then as the message suggest that one of the drives that make up the Fusion Drive (most likely the 3T HDD) is failing or has failed.

1) The new iMac's are nice machines if you can do a 24" screen instead of a 27"

2) The new Mac mini's are awesome machines. Keep in mind that they require using an external display (27" or 32") plus a mouse and keyboard of choice.

Reply

Answer 3

den.thed

Level 10

82,468 points

Nov 14, 2024 1:27 PM in response to antoniofrombakersfield

First fix the split Fusion Drive, as per > How to fix a split Fusion Drive - Apple Support

Then you can reinstall the macOS, as per > How to reinstall macOS - Apple Support

tip: use Command R or Option Command R to install the latest macOS version

Reply

Answer 4

den.thed

Level 10

82,468 points

Nov 14, 2024 8:47 PM in response to antoniofrombakersfield

Something is wonky here and this is not a 2020 iMac.

see > Identify your iMac model - Apple Support

I'm starting to concur with rkaufmann87 here and recommend that you get this iMac straightened out by an Apple Store or AASP.

Reply

Answer 5

Nov 14, 2024 8:19 PM in response to den.thed

I did try to restart a few times in recovery mode and it only allows me to try to install Sierra, with that old screen Disk Utility from yesteryear, and can only install to the new Fusion Drive. Each time it failed with the same error. Restarting the iMac without recovery mode has a folder with a ? flashing.

I posted an updated pic with the drivers selected. I also ran first aid with it saying all is good. Not sure why the OS won’t install. Appreciate the help and any other ideas you have.

Reply

Answer 6

Nov 14, 2024 9:03 PM in response to den.thed

I was going off memory and just checked the serial number from Find My, with it actually be from 2017. Time flies.

I did just find a Reddit post that says use a wired keyboard and you’ll get an option to install Ventura which would then work. Indeed a wired keyboard did now change it to Ventura (weird) but now I get this error (pic below). If you have any further help I’d be thankful but otherwise I guess driving a while to the Apple Store or a new mac will be needed (any thought on new iMac vs new Mac Mini?!)

Reply

Answer 7

Nov 14, 2024 9:14 PM in response to den.thed

I also just went back into Disk Utility and now it looks updated and so I erased the drive again and ran first aid again with no issues being presented. Looked like a good Fusion Drive. But still then get the SMART error at the Ventura install I got at the beginning of all this. The hard drive had been having a rough time for a while and I guess I didn’t realize how old it was, so probably just best to get something new. Sure seems a waste of a beautiful display though.

Reply

Answer 8

Nov 15, 2024 3:39 PM in response to den.thed

Thanks for getting back with me and sorry my slow response. In short Disk Utility couldn’t fix it and given I now know it’s 7 years old I’ve decided to get a new Mac Mini (but curious if you have a good 27” and/or 32” non-Apple monitor recommendation as I can’t do Apple prices).

But I’ve also decided I want to try to “fix” it and see what happens. I found this thread on Reddit and it seems to be exactly my issue. Basically a SMART warning (not really an error) is preventing the new OS install. So the recommendation is Terminal for OS install but as you’ll see from the pics below it can’t find my USB Installer. Any ideas?

https://www.reddit.com/r/applehelp/comments/r1li6q/incase_you_have_issues_installingupgrading_macos/?sort=new

Reply

Answer 9

rkaufmann87

Level 10

143,958 points

Nov 14, 2024 1:25 PM in response to antoniofrombakersfield

Before you dig yourself into a deeper hole, PLEASE make an appointment at your local Apple Authorized Service Provider and have them do the service for you. I am not trying to insult you however you do not seem to fully understand and you need someone that really knows what they are doing.

Reply

Answer 10

den.thed

Level 10

82,468 points

Nov 14, 2024 7:44 PM in response to antoniofrombakersfield

antoniofrombakersfield wrote:

Thank you. Terminal worked to put the Fusion Drive back together. However I still can’t install an OS. I get the screens and errors below. Any further ideas?

You're welcome.

Looks like re-fusing the drive went OK.

Post screenshots with the Fusion and Macintosh HD selected.

Run Again...? Shutdown > Restart in Recovery Mode > select Reinstall macOS and try again.

Reply

Answer 11

Nov 17, 2024 8:31 AM in response to antoniofrombakersfield

Got it all fixed! Used Terminal command from this thread and now working great! Thank you for all your help and now not sure if I should trade in or keep as an extra computer!

https://www.reddit.com/r/MacOS/comments/13caexq/comment/k6seyy7/

Reply

Answer 12

Nov 14, 2024 5:54 PM in response to den.thed

Thank you. Terminal worked to put the Fusion Drive back together. However I still can’t install an OS. I get the screens and errors below. Any further ideas?

Reply

Answer 13

Nov 14, 2024 5:55 PM in response to rkaufmann87

You are right I don’t fully understand and I’m not insulted. But I also want to learn so I’m hopeful others can help.

Reply

Answer 14

rkaufmann87

Level 10

143,958 points

Nov 15, 2024 3:58 PM in response to antoniofrombakersfield

There are too many external displays to list however if you want a 27” 5k display both Samsung & LG make direct competitors to Apples 5K display for much less $$$$.

Reply

Answer 15

Nov 15, 2024 4:45 PM in response to den.thed

Thanks again. The laptop image was to ask if it appears the path is correct with the USB Installer as Terminal said No such file or directly. Seems I’m not quite right with my Terminal command.

Reply