I installed a Samsung ev0 840 SSD into my 2012 MBP about 3 years ago and it worked like a champ until a few days ago. A few days ago, I had to restore a back onto my other HDD because my MBP stopped detecting my SSD. After restoring, it detected my SSD after a reboot for about 30 minutes before it ejected. It did this for the first three reboots, but now I am unable to get my MBP to recognize the SSD at all. It does not come up in disk utility and diagnostics did not show any errors. I am guessing either the SSD has failed or the SATA cable has possibly gone bad? I have opened it up and re seated the cable with no luck. Is there are any other troubleshooting steps that I could perform to determine if it is the cable or drive? I am hoping it is the cable as they would come much cheaper. Thanks for the support.