How to fix/repair Seagate external hard drive not recognized on Mac?

By Juno | Posted to Mac Data Recovery, updated on June 26th, 2019 |

Summary: Feel very upset when finding your Seagate external hard drive not recognized/detected on Mac? Have no data backup? Now download free external hard drive data recovery software for Mac - iBoysoft Mac Data Recovery to recover data from the not recognized Seagate external hard drive.

Plug a Seagate USB hard drive into your Mac but the drive is not recognized by the computer?

Don't worry, you are not the only one who uses famous hard drive brand like Seagate, WD, Toshiba, Samsung, etc. but encounters this problem.

 Here is an example from Apple Communities.

"I have a MacBook Pro with macOS El Capitan. My WD hard drives are recognized, but my new Seagate 1T drive is invisible. The light on the drive works, which tells me that it is drawing power from the computer. But the computer does not recognize the drive. Anyone knows how to fix Seagate external hard drive not recognized, showing up, or detected on Mac or at least recover files from the drive?"

Actually, it is a dime a dozen that external hard drive is not recognized or detected by Mac computers. Some users even say that they can see the Seagate external hard drives' light blinking but the computer just won't give any response. When an external hard drive is not working, not recognized, not detected, or not showing up on your Mac, you will feel very terrible because you can't access files nor the drive at all. Fortunately, in this article, you can find out how to fix the unrecognized Seagate external hard drive and how to recover data from unrecognizable hard drives easily.

Table of contents
1. Why does the Seagate external hard drive not recognized on Mac?
2. Baisc check - Check if the Seagate external hard drive is showing up in Disk Utility/Finder?

Part I: Why does the Seagate external hard drive not recognized on Mac?

Seagate hard drives, such as portable hard drives, external hard drives, hard drives for Mac, etc. are often used as backup media to store important files, or to transfer data among computers. However, they are prone to be damaged or corrupted as well. And it's quite common for a Seagate external hard drive to become unrecognized by your Mac all of a sudden and leave you all at sea.

You may be wondering "Why my Seagate external hard drive is not recognized by the Mac?" Well, the reasons behind this problem could be varied and there are some common ones.

  1. Bad USB port
  2. macOS update issue
  3. System failure
  4. File system corruption
  5. Motherboard issue
  6. Virus infection
  7. External drive damage or corruption, etc.

Baisc check - Check if the Seagate external hard drive is showing up in Disk Utility/Finder?

To fix the unrecognized Seagate external hard drive on Mac, the very first thing is to check whether it's the USB port's issue. Plug in the drive to another USB port or a different computer, and check if the drive is recognized, detected or shows up on Mac. If yes, congratulations. Both the external hard drive and the data on it are secure. But to access files on this drive, you need to move forward to do some basic checks and try out the solutions according to your situations.

Important thing: Check if the Seagate external hard drive is showing up in Disk Utility/Finder?

Usually, if your external hard drive is recognized/detected by your Mac, you will see this drive on the desktop and Finder. But for many Mac users, when they can't find their disk drives in Finder or on the desktop, they would say the drive is not recognized by the computer. But actually, most of the time, even if a Seagate external hard drive doesn't show up in Finder, it still can be found in Disk Utility. So please check whether the drive is showing up in Disk Utility/Finder.

There are three possible outcoms. Just check them one by one and go head to fix this issue.

Scenario 1: The Seagate external hard drive isn't showing up in Finder/on the desktop

When a hard drive is plugged into a Mac, the first impression for most users is that the icon of this drive will show up on the desktop and in Finder. But why your Seagate external hard drive is not showing up in Finder or on the desktop? Indeed, it is because you haven't set up your Mac to do so.

1. Show Seagate external hard drive in Finder

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

Step 2: Select "External disks" under "Locations", and then your Seagate external hard drive will show up in Finder.

Show Seagate external hard drive in Finder

2. Show Seagate external hard drive on the desktop

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

Step 2: Tick "External disks" to show the Seagate external hard drive on the desktop.

Show Seagate external hard drive on the desktop

 

Scenario 2: The Seagate external hard drive is recognized but not mounted in Disk Utility

If the Seagate external hard drive shows up in Disk Utility but is just not mounted, it at least means the drive is recognized by your Mac. Mounting a hard disk makes it accessible by the computer, enabling the operating system to read and write to files on the disk. Most of the time, the operating system will automatically mount your disk when you connect your USB drive to this Mac, but you if you find the Seagate external hard drive unmounted in Disk Utility, you have two solutions.

Solution 1: Manually mount the Seagate external hard drive

You can simply right-click this external hard drive in Disk Utility, and choose Mount or click the Mount button on the top of the window. You will be able to access your files if it can be mounted successfully.

Solution 2: Repair the Seagate external hard drive with First Aid

However, if the Seagate drive is unmountable or the Mount icon is greyed out, it could be some disk errors that prevent your Mac to recognize/detect the drive correctly. Fortunately, there is a native disk repair tool called Disk Utility on your Mac and you can repair this external hard drive with the following steps.

  1. Click on the Launchpad on the Dock and find Other.
  2. Locate Disk Utility and open it.
  3. Select the unmountable external hard drive in the left sidebar and choose First Aid at the top.
  4. Click Run to repair this Seagate hard drive.

Solution 3: Fix the unmountable Seagate external hard drive by reformatting.

If First Aid failed to repair this drive, the file system or the partition table of this external hard disk could be corrupted. In this case, reformatting is a feasible method to fix the corrupted file system or partition table. However, it will also erase all data stored on it. So, to avoid unnecessary data loss, you should firstly make sure you have a copy of data backup or recover files from this drive with reliable data recovery software.

iBoysoft Mac Data Recovery is useful data recovery software, which can recover data from not recognized Seagate Backup Plus drives and not readable Seagate external hard drives. Moreover, this program supports file recovery from hard drives of Seagate, WD, Toshiba, Samsnug, etc. Generally, it can recover data from formatted, unmountable, inaccessible, unreadable or corrupted hard drives. This powerful data recovery software can also recover data from Macintosh HD drives, USB flash drives, SD cards, memory cards, etc. on Mac.

iBoysoft Mac Data Recovery now is fully compatible with macOS 10.14 (Mojave), macOS 10.13 (High Sierra), macOS 10.12 (Sierra) and Mac OS X 10.11 (El Capitan), 10.10 (Yosemite), 10.9 (Mavericks), 10.8 (Mountain Lion), 10.7 (Lion). And the macOS 10.15 (Catalina) is approaching.

Step 1: Launch iBoysoft Mac Data Recovery.

Step 2: Select the Seagate external hard drive and click "Next" button to scan for all the lost data.

Recover data from not recognized Seagate external hard drive on Mac

Step 3: Double-click to preview your images, videos, word files, etc. in the searching results.

preview files on not recognized Seagate external hard drive on Mac

Step 4: Choose files you need and click "Recover" to get them back and save the recovered files to another usable disk drive.

After recovering target files from this Seagate external hard drive, you can now reformat the drive in Disk Utility without worrying about data loss.

Step 5: Click Go in the upper left of your desktop, choose Utilities in the context list.

Step 6: Open Disk Utility and select the Seagate external hard drive from the sidebar

Step 7: Click Erase on the top of Disk Utility window.

Step 8: Complete the required information for erasure, including Name, Format, and Scheme.

Step 9: Then click Erase to go and wait until the erasure process ends and click Done.

Scenario 3: The Seagate external hard drive is not detected in Disk Utility

However, if your Seagate external hard drive is not even listed in Disk Utility, it is possible that the drive has some hardware problems like bad sectors.

Usually, the symptoms would be:

  • The external hard drive makes clicking/beeping noise.
  • Files get missing/disappeared/invisible/inaccessible.
  • Documents or Folders become empty.
  • Disk information like storage capability or files system is not showing normally in Disk Utility.
  • Some other abnormal symptoms.

Confronted with such kind of hard drive failure, you'd better seek help from a local disk recovery and repair service for good.

Conclusion:

Sometimes, the Seagate external hard drive not recognized on Mac problem is just that Seagate external hard drive not showing up in Finder, not showing up on the desktop, or not mounted in Disk Utility, which can be easily solved. However, your any attempts to fix the unrecognized Seagate external hard drive may write new data to the drive and overwrite the original one. Thus, if you're facing such kind of problems, you should firstly recover data from the Seagate external hard drive with hard drive data recovery software like iBoysoft Mac Data Recovery before you set about fixing this problem.

Juno

Juno is a technical expert @iBoysoft. She has over 5-year experience in data recovery/repair technology. She loves to write data recovery tips and tutorials.

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