Fix Seagate Backup Plus Drive Not Mounting/Working on Mac

Seagate Backup Plus external hard drive is often used for Time Machine backup. But many users reported that they were unable to mount Seagate Backup Plus drive on Mac computers and may encounter error such as mount drive in Terminal failed with 72. And some say their Seagate Backup Plus can't work after being plugged into Mac.

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 the LED light is working in that case but I am not able to get it to 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. This page will help when the Seagate Backup Plus drive doesn't work on Mac.

7 solutions to Seagate Backup Plus not mounting/working on Mac

For some reason, Seagate external hard drives could not be recognized by Mac. If you can't mount the Seagate Backup Plus drive in Disk Utility, the hard drive won't work on Mac. And you can't access the data stored on it. So it's very urgent to fix the problem to make it work again.

Here are solutions to the Seagate Backup Plus not working or mounting on Mac.

Share these quick solutions to help more people who also encounter the Seagate external hard drive not working on Mac issue.

1. Have some basic checks

Sometimes, the Seagate external hard drive that's not mounting on Mac is due to a bad USB port or cable. Thus, once the Seagate Backup Plus drive stops working, you can first do some routine checks as below.

Step 1. Check if the cable of the Seagate Backup Plus drive is connected properly to your Mac
If the drive isn't properly plugged in, it will fail to mount as it received not enough or even no power.

Step 2. Make sure the USB cable is not at fault

Try using a different USB cable to see if that fixes the problem.

Step 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 into this USB port.

Step 4. Check whether the Seagate Backup Plus external hard drive is powered properly

In general, the current USB ports 2.3 and 3.0 are enough for most external portable hard drives. 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. And for Seagate Backup Plus Hub and Expansion Desktop, a power adaptor is required for the power supply.

Step 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 ask for help from Apple support.

Step 6. Check if the format of the Seagate hard drive is supported by macOS

For example, a Windows BitLocker encrypted drive will not be working on Mac originally. Your Mac computer is not able to mount it. To fix the problem, you can plug the Seagate Backup Plus into a PC and then access the drive on Windows.

2. Check whether the Seagate Backup Plus is showing up in Disk Utility

To troubleshoot this problem, you first need to know if this Seagate hard drive is detected by your Mac. Open the Utilities folder in your Applications folder. Launch Disk Utility and check the left pane then. If you can't see the external hard drive in macOS, the drive probably has been physically damaged. In that case, you should send the drive to the local repair shop. Otherwise, you can move to the next solution.

3. Check if the Seagate Backup Plus drive is mounted in Disk Utility

If the Seagate Backup Plus is mounted in Disk Utility, you should blame the wrong computer settings or an outdated computer. Fortunately, it's easy to fix these issues. Just try solution 4 and solution 5. If the external hard drive is greyed out in Disk Utility, it's not mounted. You can try right-clicking the Seagate Backup Plus and choosing the "Mount" button. If that doesn't work, the drive has some file system problems. Please follow solution 6 to repair the problem.

4. Show the Seagate Backup Plus on the desktop

If the Seagate external hard drive is mounted in Disk Utility, but it still doesn't show up on Mac. First of all, you should make sure the settings in Finder display drive icons on the desktop.

1. Go to Finder > Preferences > General tab.

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

5. Repair Seagate Backup Plus drive via First Aid

The Seagate external hard drive that's not mounting on Mac can be caused by file system problems. 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/corrupted Seagate Backup Plus external hard drive in Disk Utility by following the steps below.

1. Go to Disk Utility.

2. Click "View" in the top menu bar (Or click "View" on the top window). Then select "Show All Devices".

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

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

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

6. Update the software on Mac

Software updates keep your computer and programs secure, deal with quite a few bugs, and provide new features. Out-of-date software can cause a variety of issues. It's possible that the operating system will become sluggish and the connected device may not function properly. Fortunately, you can easily update the software on Mac.

Case 1. Update the software on macOS Mojave or Catalina. If you upgrade to macOS Mojave or macOS 
Catalina, you should choose "System Preferences" from the Apple menu, then click "Software Update" to check for updates. If any updates are available, click "Update Now" to install them.

Case 2. Update the software on earlier macOS versions. Just launch the Mac App Store, click the "Update" tab on the top, and then choose "Update All".

7. 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 lost data from the Seagate Backup Plus external hard drive as soon as possible.

Here is a video tutorial that shows you how to recover data from an external hard drive step by step. You can follow it to get your lost files back easily and quickly.

Step 1. Recover lost data from the unmountable/corrupted Seagate Back Plus

iBoysoft Data Recovery for Mac is the best external hard drive data recovery software. It can easily recover files when the external hard drive is not working or mounting on Mac. Also, it can recover deleted photos and lost data from formatted drives, unreadable drives, corrupted drives, and recover deleted/lost partitions, etc. It's compatible with macOS 12/11/10.15/10.14/10.13/10.12/10.11/10.10/10.9/10.8/10.7 and works fine on M1, M1 Pro, and M1 Max Mac.

Here's how to Recover lost data from the unmountable/corrupted Seagate Back Plus:

Step 2: Reformat the Seagate Backup Plus to make it work

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

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

Have fixed your Seagate external hard drive that's not mounting on Mac? If yes, don't hesitate to share and save these feasible ways.

Bonus Part: Introduction to different Seagate Backup Plus drives

You probably use a Seagate desktop drive like Backup Plus Hub and Expansion. Or you could use a Backup Plus Portable drive like Ultra Touch and Slim. No matter which Seagate Backup Plus drive you choose, it could not work on the Mac for some reason.

Therefore, it's important to know the differences between those Seagate Backup Plus drives. This helps you to use the Seagate Backup Plus drive more correctly and efficiently, and then avoid hard disk corruption.

• Seagate Backup Plus Hub: This Seagate Backup Plus Desktop drive has large capacities with cross-platform compatibility, which means you don't have to format the drive for both Mac and Windows again. It's an all-in-one data hub and recharging station for tablets, smartphones, and cameras.
• Seagate Backup Plus Ultra Touch: Backup Plus Ultra Touch portable hard drives feature password protection and hardware encryption, USB-C compatibility, and file sync. You can't open the Seagate Backup Plus drive on Mac until it's unlocked. Moreover, an NTFS for Mac software is needed to use Backup Plus Ultra Touch on Mac, as it's preformatted with NTFS.
• Seagate Backup Plus Slim: Seagate Backup Plus is small enough for a loaded laptop bag. It's an ideal external hard drive with easy portability and enough storage space. But avoid dropping your Seagate Backup Plus drive during transportation, in case it's damaged and not working.
• Seagate Backup Plus Portable: Backup Plus portable drives offer easy-to-use software tools like Seagate Dashboard so that you can schedule automatic backup and mirror folders easily.

Conclusion

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

If you have any suggestions to solve this issue or experience any questions when using iBoysoft Data Recovery for Mac, please feel free to let us know.

Also read: Fix External Hard Drive Not Showing Up/Mounting on Mac Sequoia

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