Solution 4: Repair external hard drives by reformatting Step 7: When fsck is finished checking and repairing the errors in your external hard drive, type reboot into the command prompt and press Enter to restart your Mac.Step 6: Type in /sbin/fsck_hfs -fy /dev/ (You need to replace hfs with the file system of your external hard drive and replace with the identifier of the external hard drive).When it stops, type in /sbin/fsck –fy, then press Enter. Step 5: Some white text will scroll by quickly.This will boot your Mac into Single User Mode. Step 4: Restart your Mac and, before the Apple logo appears, hold down 'Command + S' keys.Step 3: According to the disk information, locate the external hard drive you want to repair in the list, and then find its drive identifier.Step 2: Type in diskutil list to list all the connected drives on your Mac currently.Try it and you may have luck with this command line. If Disk Utility can't repair external hard drive and your hard drive is not readable by your Mac computer still, there is an alternative way called FSCK command that can repair your external hard drive. Solution 3: Repair external hard drives with FSCK command Step 3: Click First Aid on the top and click 'Run' to repair this external hard drive.Step 2: Select the external hard drive you want to repair in the left sidebar.Solution 2: Repair external hard drives with First Aidįirst Aid in Disk Utility is able to repair many disk problems, for instance, multiple apps quit unexpectedly, the file system of a hard disk is corrupted, or an external device doesn't work properly, etc. Step 3: Check if there any software update is available in your APP store in that an outdated driver could make your external hard drive not recognizable.Step 2: Try another USB cable to connect the hard drive to your Mac.Step 1: Reinsert the external hard drive into another USB port or to another Mac computer.Therefore, before you set about repairing this external hard drive, the first thing you can do is to check the connections. Sometimes, your external hard drive is not showing up or working normally just because of the faulty connections. Solution 1: Check the IDE / SATA USB Connections And the following is a general graphic about external hard drive repair and recovery. In this part, you will see 4 feasible solutions to repair external hard drives that are corrupted or not detected on Mac mini, MacBook Pro/Air, etc.

Disk drive repair