How to Troubleshoot an External Hard Drive that Is not showing up on Mac Issue?

When you plug in an external hard drive on your Mac, for example, the USB drive, it’s possible that it won’t show up on the computer. This can be really troublesome and annoying especially when you are in a hurry. Then, how to solve this problem? 

Why is your external hard drive not showing up on Mac?

Before we tell you how to solve the problem, we would like you to know some potential reasons why this happens. As a result, you may understand the solutions below better. The common reasons for this phenomenon are listed below. 

  1. The external hard drive is not properly plugged in. For instance, maybe it’s not plugged in tightly.
  2. There is a broken or faulty cable that can’t connect your external drive with the computer.
  3. The port is damaged. The port of the drive can be destroyed due to human factors or natural wear.
  4. The macOS could also be responsible for an unshown external hard drive. If the operating system misfunctions, it will also affect the presence of the external hard drive.
  5. The external drive is set up to be hidden by the computer.
  6. The third-party software hides the external hard drive.
  7. The file system of the external hard drive is not compatible with Mac operating system. As a result, your computer can’t recognize the file system and then mount the external HD.
  8. The file system is compatible with the operating system but it’s corrupted. In this case, the OS has a hard time recognizing the file system and preparing the disk for use as well. 

No matter which reason has caused the trouble, the most important task now is to troubleshoot the issue. Now let’s dive in the solutions. 

How to troubleshoot the issue?

As we mentioned above, an unshown external hard disk may be caused by different reasons. If you know the exact reason, you can quickly find the relevant solutions. However, when you are not sure what’s going wrong, you can only try the solutions one by one. Here are the solutions you can take into consideration.

Method 1: Verify the connectivity 

  1. Reboot your Mac. It’s possible the external drive will be seen after the computer reboots.
  1. Check if you plug the external drive in the right way. Make sure the connection is neither loose nor wobbly.
  1. Check all the hardware to see if there’s any physical fault. Check the port,the cable and the hub. If there’s something wrong about one of the devices, try on another one. 

Method 2: Make the Mac or third-party software unhide the drive

  1. Change the computer’s Preferences settings. To make the external HD show up, 
  • Go to Finder from the top menu bar.
  • Select Preferences. 
  • Under General and Sidebar tab, choose External disks option. 
  1. Unhide the external hard disk using the same third-party software. The specific steps depend on what software you are using.

Method 3: Repair the external hard drive to get rid of the file system errors

Repair your external hard drive with the help of the First Aid. Here are the steps:

  • Launch Disk Utility.
  • Choose the grayed out the external hard drive from the left sidebar.
  • Click the “First Aid” button on the top and then choose “Run” to confirm this operation.

Method 4: Format the external hard drive 

Whether the file system of the disk is corrupted or incompatible with the operating system, you can format the drive to make them function in the right way. Then it can be recognized by the computer and appear on your Mac. But you need to restore data before you format the drive. That’s because formatting a disk will reassign a new file system on the drive and make all stored files inaccessible. If you already have adequate backups or no important files on the storage, go ahead to format it using Erase utility in Disk Utility. Here are the steps:

  • Launch Disk Utility, located in Finder > Applications > Utilities.
  • Locate the drive name from the left side of Disk Utility and click on i.t
  • Click on the “Erase” tab across the top.
  • Name the drive with the one you like
  • Next to “Format:” click the contextual menu and select Mac OS Extended (Journaled) for Mac only or FAT/ExFAT for both PC and Mac.
  • Click the “Erase” button and confirm again on the next pop-up window.

Hopefully those methods have helped you resolve the problem. If not, you can check iBoysoft’s tutorial for more methods. 

Bonus tips: mistakes you don’t want to make on external hard drive data recovery 

If you have come to the solution that asks for formatting but you don’t have a backup of your valuable information, you will need data recovery using professional tools. To ensure the highest success rate and reduce the number of corrupted files, we want to offer some useful tips on the mistakes you should avoid before or during the recovery.

  1. Keep saving files to the external hard drive. Keep writing new data onto the drive may overwrite the original files, leaving the original files completely unrecoverable or corrupted. 
  2. Don’t back up regularly. We know many of you do back up, but you don’t do that regularly. The downside of not backing up regularly is that a few data will be missing due to the time gaps.
  3. Use untrustworthy data recovery software. The software with little authority may bring the virus to both your computer and the external drives.
  4. Save recovered files to the failed hard drive. Saving recovered files improperly may put your hard work in vain. The failed hard drive has unsolved issues and are not suitable for storing data.


To sum up, there are lots of reasons as well as solutions for Mac not showing up an external hard drive. All you need to do is figure out the possible reason and find the solution for it. What’s more, when it comes to data recovery, remember to avoid mistakes to increase the recovery success rate. 

Leave a Comment

Exit mobile version