Respuesta a "Hard disk not getting "detected"?"I’ve had and solved this same issue multiple times with two different WD My Passport drives; I thought they both had failed and we’re not recognizable on my Mac or any other computer. You must boot your Mac in recovery mode (CMD-R while booting), mount, and run First Aid on the disks through the Disk Utility there. YOU MUST use the recovery mode Disk Utility to repair; it will not appear in your booted Disk Utility. I hope that someone finds this useful. I thought I had lost years of music production backups, but i was able to save it with this method. Will be switching to a different brand of drives.