iMac Fusion Drive failed; install Monterey on external SSD?

Chacos wrote:

I have a 2022 mac studio and a 2025 airbook. I'm not able to download using the recovery mode as the progress bar gets stuck during installation onto the SSD connected the imac.

How are you accessing recovery mode?

Try using Command + Option + R so it bypasses the local recovery mode on the bad internal drive.

At what point does the progress bar get stuck? I'm assuming it booted into recovery mode and you clicked "Reinstall macOS Monterey" (may be "Install macOS Monterey"). There is the initial download & copy phase followed by a reboot where the second installation phase occurs.

Is there any error message?

I just tried downloading Monterey to my airbook but it goes into auto update and finds it incompatible,

Exactly.

Where would I find the right computer to download software?

For Monterey you need a model 2015 to mid-2022. You say you have a Mac Studio (2022) model which should be able to download the Monterey installer.

macOS Monterey is compatible with these computers - Apple Support

How to download and install macOS - Apple Support

is it worth it? Imac would be used for basic stuff only

Only you can say. Personally I try to keep devices working as long as possible, but that is me (I do have limits though).

Once you have macOS installed & configured, then I would erase both internal drives....although if the Hard Drive portion of the Fusion Drive is failing, it may not erase depending on the severity of the failure. In fact, I would want to attempt to write zeroes to the whole internal Hard Drive using the secure erase option to overwrite your data to destroy it (may not be possible if the HD is failing).

If the Hard Drive can be erased, then I would suggest configuring macOS to prevent auto mounting of the failing internal HD by using the information in the following article (although if you erase it with the APFS file system, you need to modify step #8 by replacing the reference to "hfs" with "apfs":

Prevent a volume from mounting at startup - Apple Community

You can try booting into Internet Recovery Mode using Command + Option + R to attempt to access the online installer for the last compatible version of macOS.

Or you need access to another Mac that can run a version of macOS that this broken iMac can use so you can create a bootable macOS USB installer. Generally for macOS Monterey you need a Mac model 2015 to mid-2022.

Your "2016" model designation is not correct since Apple only had iMac model designations for 2015 and 2017 so I'm guessing yours is a 2015 model since you are asking about Monterey and not Ventura. In that case, you can also install macOS 10.11, 10.13, 10.15 which gives you a lot more options for finding a Mac you can use to create a bootable macOS USB installer.

• • macOS 11.x -- model 2015 to mid-2022
  • macOS 10.15 -- model 2012 to mid-2020
  • macOS 10.13 -- model Late-2009 to 2018
  • macOS 10.11 -- model 2007 to 2015

FYI, when installing macOS 10.13+, you need to erase the whole physical drive as GUID partition and APFS (top option). For macOS 10.11 (or even 10.13) you need to erase the drive as GUID partition and MacOS Extended (Journaled). With macOS 10.13+, Disk Utility hides the physical drives from view so you will need to click "View" within Disk Utility and select "Show All Devices" before the physical drives appear on the left pane of Disk Utility.