How to fix Seagate Backup Plus drive not mounting, working on Mac?

By Katrina | Posted to  Mac Data Recovery on February 8th, 2018 |

Summary: When plugging your Seagate Backup Plus into a Mac computer, you may find the drive stops working and is unmountable in Disk Utility. Have you troubled by the issue? This post will give you 4 workable solutions to fix Seagate Backup Plus drive not mounting/working on Mac.

A large number of users have reported that they were unable to mount Seagate Backup Plus drive on Mac computers, or Seagate Backup Plus couldn't work on Mac after plugged in. Here is a real example.

"I really need your help. My Seagate Backup plus just stopped getting detected (led not working anymore) with my MacBook Pro 2016 model (with USB Type C to USB 3 connector) suddenly. It was working fine 1 month before. I tried this backup disk with a Windows computer and it works and LED light is working in that case but I am not able to get it work with my MacBook Pro anymore. Any idea guys?"

In fact, this issue is very common, especially for those who frequently share the same drive between different computers. Now, let's go through the solutions to fix the Seagate Backup Plus not mounting/not working on Mac issue.

6 solutions to fix Seagate Backup Plus not mounting, not working on Mac?

Seagate Backup Plus external hard drive is often used to back up important files. If the Seagate external hard drive is not recognized or detected by your Mac, you can't mount it in Disk Utility and access the data stored on it. So it's very urgent to fix the problem to make it work again. Now follow the solutions as below.

Solution 1: Have some basic checks

Sometimes, the Seagate Backup Plus drive could not be mounted on Mac is due to the bad USB port or cable. Thus, once the Seagate Backup Plus drive stops working, you can first do some routine checks as below.

  1. Check if the cable of the Seagate Backup Plus drive is connected properly to your Mac.
  2. Try a different USB cable to see whether it's the USB cable is at fault.
  3. Check if the USB port is damaged. Plug the Seagate Backup Plus into another USB port if you have another one. Otherwise, insert another external storage device in this USB port.
  4. Check whether the Seagate Backup Plus external hard drive is powered properly. In general, the current of USB port 2.3 and 3.0 are enough for the most external portable hard drive. But sometimes this amount of current may be insufficient while the drive is spinning up. In this situation, you can try to connect the Seagate Backup Plus with a USB Y cable if you have one.
  5. Access the drive on other Macs. Connect the Seagate Backup Plus drive to another Mac computer to see whether it works on that one or not. If the drive works on another Mac computer, there is something wrong with your Mac computer rather than the drive. What you should do is to ask for help from Apple support.
  6. Check if the Seagate hard drive has been formatted incorrectly. The problem could occur if the drive's format is not supported by macOS. For example, if the drive is a Windows BitLocker encrypted drive, your Mac computer is not able to recognize it. To fix the problem, you can Plug the Seagate Backup Plus into a PC and decrypt the drive on a PC.

Solution 2: Show the Seagate Backup Plus in the desktop

If the Seagate hard drive is not showing up on Mac, first of all, you should make sure the setting in Finder will display drive icons on the desktop.

Step 1: Go to Finder > Preferences > General tab.

Step 2: Select "External disks" under "Show these items on the desktop" and then our connected external hard drive will appear on the desktop.

Show Seagate Backup Plus on the desktop

Solution 3: Update Mac drives

A driver is a software that lets the operating system and a hardware device communicate with each other. If a driver is missing or outdated on Mac, the device may not function properly. Fortunately, you can easily fix this problem by updating the driver. Just launch the Mac App Store, click the "Update" tab on the top and then choose the "Update All".

Update Mac drivers

Solution 4: Repair Seagate Backup Plus drive via First Aid

Disk Utility's First Aid is a built-in tool on Mac to deal with errors related to disks, such as file system corruption. So you can try to fix the unmountable Seagate Backup Plus external hard drive in Disk Utility by following the steps as below.

Step 1: Go to Utilities > Disk Utility.

Step 2: Click "View" in the top menu bar. Then select "Show All Devices".

Click Show All Devices in Disk Utility

Step 3: Select the Seagate Backup Plus external hard drive from the left sidebar.

Repair Seagate Backup Plus drive via First Aid

Step 4: Click "First Aid" on the top of the Disk Utility window.

Step 5: Click "Run" to perform hard disk diagnostics and fix the not mounting/not working Seagate Backup Plus.

Solution 5: Fix the not mounting or working Seagate Backup Plus drive by reformatting

If First Aid failed on the external hard drive, it might have some serious errors that are beyond its reparation capability. In that case, you need to recover data from the not working Seagate Backup Plus external hard drive as soon as possible.

Here is a short video which shows you how to recover data from unmountbale/corrupted external hard drives:

iBoysoft Mac Data Recovery is free external hard drive data recovery software that can recover deleted photos, recover data from formatted drives, recover data from unmountable drives, recover data from corrupted drives, recover deleted/lost partitions, etc. It's compatible with macOS Mojave 10.14/High Sierra 10.13/Sierra 10.12/10.11/10.10/10.9/10.8/10.7.

Step 1: Download and install iBoysoft Mac Data Recovery on Mac.

Step 2: Launch iBoysoft Mac Data Recovery.

Recover data from not mounting/working Seagate Backup Plus external hard drive

Step 3: Select the Seagate Backup Plus and click the "Next" button to scan for all lost data.

Step 4: Preview the searching results, choose files you want to get back, and click "Recover" button.

After recovering data from the unmounted Seagate Backup Plus, you can now go to Disk Utility and reformat it without worrying about data loss.

Step 5: Launch Disk Utility from Utilities and click "View" in the top menu bar. Then make sure the "Show All Devices" is ticked.

Step 6: Select the unmounted Seagate Backup Plus. Click Erase on the top of the window, and follow the on-screen steps to reformat it.

Solution 6: Seek help from the local data recovery company

If unfortunately, you can't reformat the Seagate Backup Plus, it must have physical issues. In this case, you have to look for help from a local data recovery company.


No matter what caused Seagate Backup Plus not mounting/working on Mac issue, such as logical problems and physical damages, the most important thing is to back up important data or recover data with free Mac data recovery software. iBoysoft Mac Data Recovery is a powerful and reliable data recovery tool on macOS which supports various external drives, including external hard drives, SD cards, USB flash drives, etc.

This article can also be used to fix WD external hard drive not working or showing up on Mac. If you have any suggestion to solve this issue or experience some question when using iBoysoft Mac Data Recovery, please feel free to let us know.


Katrina is a data recovery expert @iBoysoft who loves to help readers solve various data recovery problems.

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