Sometimes it is necessary to repair a USB key on a Mac when you have not ejected it correctly, when the main partition is damaged, when the files are damaged…. Unfortunately there are many examples! We’ll show you how to first isolate your remaining files by recovering them if possible, and then how to repair this USB key on macOS / Mac OS X. If you’re running Windows 10 or other versions, consider reading our tutorial Repairing an Unrecognized USB type in Windows.10, 8.1, 8, 8, 8, 7, XP.
Repair a USB key on Mac: recover files first …
Back up your data by simply copying and pasting, if you can. Otherwise, before going to the USB stick repair part, as a precaution, try to recover as many objects as possible from this USB stick. We have already dedicated a tutorial to recover deleted files under macOS / iOS (with Disk Drill) and another to restore deleted files on Mac (EaseUS Data Recovery). We invite you to read these two tutorials. Then, we recommend that you download Disk Drill 3 or its EaseUS Data Recovery Wizard for Mac, which is just as effective. Insert the defective USB key. In our example, the USB stick is a 16 GB Kingston. In the Hardware Disks section, click in front of this USB key on the Recovery button.
After the media analysis phase (it may take some time), check what you want to recover and isolate these valuable files on disk, iCloud drive or just another USB key.
Repair a USB key on Mac: Disk Utility
From your Mac’s Finder and in the Applications and Utilities folder or directly through a Spotlight search (cmd + space bar with the keyword «Disk Utility») start the MacOS disk utility that is used to format a disk, or a USB key on a Mac, but also to solve any problem in the hard drives. Select the USB key by clicking on it.
Tap the SOS icon An overlay window displays «Do you want to run SOS on …». Click the blue Run button.
After the verification phase, the USB stick will be repaired as soon as possible. They will read the statement «Volume X seems to be in good condition».
Finally, try using the USB stick normally by copying / moving files and see if the issue is resolved, which should be the case!