How to fix an external drive that won't mount on a Mac

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Direct links

  • Check Finder settings
  • Disk Utility helps

Most of the latest Macs don't offer user-accessible storage, so users are locked into the configuration they choose when ordering. Often, that's less than necessary as your storage needs increase. You could turn to cloud storage providers to get enough space, but then you'll have to pay a monthly subscription fee. Using an external drive with your Mac is more cost-effective, but what happens if macOS stops mounting that drive? External hard drives are more prone to damage because their portable nature means they get thrown around more often than internal drives. Macs have built-in tools to fix many common drive problems. Here's how to use them to get your external drive back up and running.




Check all cables

Try data, power and if possible another device

If your external drive doesn't show up when you plug it into your computer, the first thing you should do is check all the physical connections. The power source for your external drive is often the problem, especially if it's a larger external drive with a secondary power cable. These types of drives often have a power switch, so check the switch position and see if you can feel the drive spinning inside the case. If you're using an external SSD, you won't be able to feel any vibrations even if it's working properly, but there may be an indicator light that tells you whether the drive is on or not.


For other types of external drives, try using a different USB cable, a different USB port on your Mac, or a second computer if you have access to one (in case the problem is on the computer side). If your phone and external drive have USB-C connectivity, you can also try connecting the two together to see if they show up in the phone's file manager.

Your external drive may be damaged

Because of their portable nature, it's possible that your external drive won't mount because it's corrupted. If it's a spinning hard drive, signs of physical damage include overheating, strange noises like clicking, scratching or screeching, or no vibration when plugged in. For external SSDs, you may not get any clues other than the drive not being recognized by the Mac. If the external drive is showing any of these signs and you have data on the drive that you want to recover, it's time to talk to a data recovery expert.


Check Finder settings

Did you know that Finder hides external drives?

Screenshot of the macOS Finder window

Finder, a file manager for macOS, can be customized to show only the drives and locations the user wants. For example, external drives may be mounted correctly, but Finder is set not to show them. Hover over the left-hand “Locations” menu item and click the arrow to make sure the section expands and the available drives are visible.

If you connect an external drive and still don't see it in Finder, you can use Preferences to make it appear again.


  1. Open Finder. Depending on your macOS version, go to Settings (macOS Monterey and earlier) or Settings (macOS Ventura or later).
    Screenshot of the macOS Finder menu with the Preferences link highlighted

  2. In the General tabCheck the box next to External hard drives so that they now appear on the desktop.
    Screenshot of macOS Finder preferences with highlighted checkbox to show external drives on the desktop

  3. In the Sidebar tabchoose External hard drives from the list of check boxes.
    Screenshot of Finder Preferences in macOS showing the sidebar options for displaying external hard drives

  4. Your external drives should now appear in the sidebar and on the desktop.
    Screenshot of the macOS Finder with two external drives highlighted


Disk Utility helps

Fixes most external drive problems

Screenshot of macOS Disk Utility

If your external drive still doesn't show up after checking that Finder has the correct display settings, another built-in utility can often get your external drive working properly again. Disk Utility can force-mount your external drive if Finder is having problems.

  1. Search for Disk Utility in Spotlight or Launchpad and run the utility.
    Screenshot of the macOS Launchpad with the Disk Utility icon

  2. When you see your external drive in the sidebar, select it and then select Mount top right so that it appears in Finder.
    Screenshot of macOS Disk Utility with mount option highlighted


Provide first aid

One of the most common reasons an external drive won't mount on macOS is a problem with the file system. To fix this, Disk Utility has a first aid tool similar to the CHKDSK utility on Windows PCs. This tool will scan the drive and automatically fix any problems it finds, hopefully leaving you with a drive that can actually be mounted. Open Disk Utility as you did before so you're ready for the next steps.

  1. Choose First aid in the upper right corner of the Disk Utility window, and then select Run.
    Screenshot of macOS Disk Utility prompting to run First Aid

  2. Wait for First Aid to finish. You will see a list of all the problems the utility fixed and whether the repair was successful.
    Screenshot of the successful Disk Utility First Aid program on macOS


To avoid problems with external drives, a good backup strategy is essential

Macs make backing up your files easy because Time Machine does the hard work once you point it to a drive. If you're using your only external drive as a Time Machine location, you'll also want to back up that drive to another storage device, such as a reliable NAS device or a cloud storage provider. Otherwise, you risk losing your backups if something happens to your external drive.

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