iMac Internal HDD not seen in disk utility or recovery

Hi there!

While it looks like the internal hard disk drive has failed, since it appears you had a Fusion Drive, you may be able to install macOS to the internal 120GB SSD.

First, shut down your Mac, then startup intro Internet Recovery mode:

1. Restart your Mac.

2. Immediately press and hold Option-Command-R to start up from macOS Recovery over the internet and upgrade to the latest version of macOS that’s compatible with your Mac.

3. If requested, choose an administrator account, click Next, enter the password for the account, then click Continue.

Next, choose Disk Utility, and erase the internal SSD disk:

1. From the utilities window, select Disk Utility and click Continue.
2. Select the Apple SSD in the sidebar of Disk Utility.
3. Click the Erase button in the toolbar, then enter the requested details:
   1. Name: Macintosh HD
   2. Format: APFS or Mac OS Extended (Journaled), as recommended by Disk Utility
   3. Scheme: GUID Partion Map
4. Click Erase.
5. Quit Disk Utility.

Finally, you can reinstall macOS:

1. Select the option to reinstall macOS. 
2. Click Continue, then follow the onscreen instructions.

Let us know if this works!

- Jack

Your internal rotating disk is dead, Jim.

You will need to replace it. I suppose you could just boot from an external, but replacing the internal drive is not difficult and you could install an internal SSD in it's place and gain a bunch of speed too.

This involves a little plastic "pizza cutter" tool that you roll around the joint between the glass and the aluminum back of the iMac. Then new adhesive tape after the repair. These items are available in a kit for very little money.

[Edited by Moderator]

I can not see the ssd in recovery /utilities at all and when I try to reload OSX I get to the point where it asks for the drive and nothing comes up so I can not continue the Mac air will however boot from external drive

When I got to utilities there is no view just apple disk image and below that OS base in left window disk utility on top first aid /partition/erase/unmount/info. OS X Base System 2.01 GB disk image external physical volume X extended apps photos/ movies/ all 0 other 1.3 Gb free 715 .3 mb available

Start up from macOS Recovery

Option-⌘-R

In Disk Utility>View, select Show all Devices, highlight the top left entry.

Run Disk First Aid on all items in the left panel, from top down.

Does the SSD show up there?

If your Mac has a Fusion Drive and you see a flashing question mark or alert, see the troubleshooting section of the Apple Support article About Fusion Drive, a storage option for some Mac computers.

If you continue to have problems with your disk or it can’t be repaired, it may be physically damaged and need to be replaced. For information about servicing your Mac, see Find out how to service or repair your Mac.

In Terminal…

diskutil resetFusion

How to fix a split Fusion Drive - Apple Support

Also when I look at OS X it is not bootable not journaled ejectable yes solid state no

Tough to tell, but have ou tried the diskutil resetFusion?