Chosen Solution
I have a 27” IMac 2012 with a 3TB Fusion drive. The other day I got a white screen, which prompted me to run disk utility. Trying to run first aid my fusion setup was RED( both drives). i tried fixing but it wouldn’t. So I tried doing an internet restore. I am currently at CATALINA but it prompts me to start with Mountain Lion. When it asks for a location there are no drives shown. I’m assuming the drive is trashed So, my question is- can I just remove the fusion drive and replace with a standard hdd?
Short answer: Yes, but it’s an effort. And you have options. Apple’s Fusion drive is a flash drive mounted on the back of the logic board between the optical drive and the I/O ports, plus a SATA hard drive that’s a lot more easy to access. To fully remove the Fusion drive will require you to just about fully disassemble the iMac in order to get to the flash drive part. So you’ve got options. If you’re not willing to fully disassemble your iMac then I’d suggest simply replacing your SATA hard drive with a SATA SSD. Doing so will break your existing Fusion drive (which is fine since it’s dead anyway). Then just format the new SATA SSD, install the OS onto it, and ignore the flash drive (as you don’t know for sure that it’s still good). Alternately, if you choose to go the full disassembly route on your iMac then I’d suggest replacing that flash drive with a new, larger flash drive from someplace like OWC. You could (for example) replace your existing flash drive with a 2TB flash drive, remove and discard your spinning drive, and away you go. Such a configuration would be faster than the SATA SSD. Alternately again, you could go Full Monty on your iMac and install both a new flash drive AND a new SSD, then create a new Fusion drive and enjoy your newfound godlike powers.
