I have just retired my late 2014 27” 5K Retina iMac but have saved the display which I have rebuilt as a standalone display (works really well too) Before i took the iMac apart the HDD was working perfectly. I bought a UGreen USB caddy which read another HDD no problem. This was previously in a windows machine however. I am using a new mac mini and also a macbook air. The iMac drive in the caddy isnt recognised by either. In disk utility it shows greyed out and states it is unmounted. Really stuck on what to do as I really need the info on it. Any suggestions as to how to get the drive to read gratefully received