For reference, I previously successfully installed a SSD (WD BLUE) on my MBP Pro 2011 with no issues, but for the life of me I can't get it to work on my iMac (A1311, mid 2011).
SSD: Crucial MX500 (I chose this drive over OWC as it was slightly cheaper and came with 5 year warranty vs 3 year with OWC).
These are the steps I did:
- Attached the SSD via USB2 to SATA to initialize the drive
- On a separate USB drive, created a bootable USB High Sierra Installer
- Removed Apple OEM HDD, installed SSD with thermal sensor
- Booted in Option mode (pressing the Option button only)
- Selected the USB drive which had the installer
I can't select the SSD to install.
I can install macOS on the SSD using a USB connection and boot from there without any problems.
I tried installing the SSD internally with and without the thermal sensor to ensure it wasn't faulty, it appears to be a non-issue.