How to find an external drive that does not appear on a Mac?

Here’s what to do when you can’t access an external drive on your Mac because the USB drive isn’t showing up. You’ll also learn how to format a drive for Mac and PC.

Normally, when you plug an external hard drive into your Mac’s USB port, you’ll see it appear on the desktop (a.k.a. mount on desktop). You can also see it in the Finder, in the left column, under Locations (or Devices on older versions of macOS). If the drive doesn’t appear on your Mac, it’s likely that it wasn’t formatted correctly, was corrupted, or is defective.

We’ll show you how to determine if the reason the external drive isn’t showing up on your Mac is due to a problem with the drive itself, the cable or the port, and how to fix the problem and access the data on your drive.

This article assumes that you have an external drive that connects to your Mac via a USB-A, USB-C or Thunderbolt port. If you have a NAS drive that connects via the network, you should read this article on connecting to a NAS drive.

How do I fix a drive that won’t display on a Mac?

There are a number of reasons why your hard drive, flash drive, USB drive or SSD may not be displaying. It may have been formatted incorrectly, it may be corrupted, it may have a faulty (or inadequate) cable, or it may be something else.

If you follow these steps, you should be able to identify the cause and fix the problem that prevents your external drive from opening on your Mac. Let’s continue our article mac external hard drive not recognized!

1: Change your preferences

Fortunately, there is a very simple solution to get the hard drive to mount on your desktop. Try the following to make sure your Mac is configured to show mounted drives on the desktop.

• Open the Finder.
• Click Finder in the menu at the top of your screen.
• Choose Preferences > General and make sure the “External drives” box is checked.

If the external drive is already set to appear on the desktop, continue with the steps below.

2: Check the cable

The first instinct is always to check that it’s plugged in, but we’re sure you’ve done that. The problem may be with the cable.

One of the main reasons drives fail to mount is that the drive is not getting enough power. If the drive is powered by a USB-A cable, you need to check that the power supplied to the drive is sufficient. Very old Macs may require a USB power cable, a cable that splits into two USB connectors that must both be plugged into your Mac, in order to provide sufficient power to the drive. Also, make sure the drive doesn’t have an external power supply that it should be using.

As for the cables, make sure they are not at fault. Try using a different cable with the drive to see if that solves the problem. Also, if you are using a USB port via a hub, make sure that is not the cause of the problem.

Also check that the port on your Mac is not the cause of the problem. Try plugging into another port. Or if you only have one, plug in another device and see if it works properly.

3: Try another Mac, then a PC.

The next step is to try plugging the drive into another Mac. If it doesn’t mount either, you’ll know there’s a problem with the drive. If it does mount, the problem is with your Mac.

The next step is to try connecting the drive to a PC. If the drive mounts on the PC, you’ve probably discovered the problem: the drive is formatted for PCs and can’t be read by your Mac.

4: Use the disk utility to access the disk.

If the various checks above suggest that the disk is defective, you can use Apple’s Disk Utility program to access the disk and possibly correct the cause of the problem. Here’s how to do it:

• Find Disk Utility by opening Spotlight (cmd+spacebar) and type Disk Utility, press Enter to open the program.
• Look in the left column to see if the hard drive appears there.
• If you see the hard drive in the disk utility, check to see if there is a volume under the drive. If there is, click on it and select Mount. If your Mac has already mounted the drive, the Unmount option appears instead. (If no volume is listed, your Mac is not able to access the disk. The Mount option will be grayed out).

If, after performing first aid, the Mac finds errors that you can fix, you may see the Repair Disk option. If so, go ahead and make the repairs.

5: Always disconnect your drive properly

We have one last suggestion to make, which is more about preventing this error from happening again.

Make sure your external drive won’t be damaged in the future by always disassembling the drive properly after using it. Don’t just unplug the USB cable. To unmount your drive, you can right-click (control-click) the icon on the desktop or in the Finder and choose Eject. Apparently, most disk problems are due to the disk being removed without being ejected properly.