Mac Won T Recognize Seagate External Hard Drive

Sometimes our MacBooks, MacBook Pros, or Macs don’t recognize our external drives or external thumb drives. This situation often occurs after you initially eject the external drive and unplug it from your computer. When you try to plug in the drive again, your Mac no longer sees it. It won’t mount at all and acts as if it’s utterly invisible to macOS.

In many cases, the only way to solve this problem is to completely remove the external drives and then restart your MacBook or Mac several times until the drives finally show up again.

There are several reasons why your Mac won’t recognize a drive. If you have a disk already mounted and your system goes to sleep, it also powers down ports, including USB ports. When you wake your Mac up, for whatever reason, your external drive does not wake up.


  • Quick Tips
  • The Potential Causes
  • Check Your Settings
  • Reset NVRAM
  • Terminal to the Rescue!
  • Does Your MacBook Shut Down When You Plug In Your External Hard Drive?
  • External Drives Very Slow after macOS Update?
  • Reader tips

Quick Tips

If your Seagate external hard drive can be recognized via another USB port, problem solved, all you need to do is reconnect your hard drive to another port. If your Seagate external hard drive won’t work in neither situations, your hard drive could be at fault. You might need to consult the technical support of Seagate to see if your data in.

Follow these quick tips and get your Mac to recognize and mount your external drives

  • If using a hub, try using a different port on your Mac for the hub or plugging your external drives directly into the Mac
  • Check your USB connections for a snug fit or frayed cables, missing pins
  • Connect the USB device to its own power source, if possible
  • Update Finder Preferences to show external drives
  • Perform an SMC & NVRAM reset
  • Run Disk Utility to Mount, Verify, or Repair Drives
  • Use Terminal Commands diskutil list, diskutil info disk, & diskutil eject disk
  • Diagnose errors with Console

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The Potential Causes

Connections Rule!

It’s easy to plug things in at random times, and usually, our Macs and MacBooks get it right and recognize everything. That’s why most USB devices are called plug-and-play. But this doesn’t always hold true. So it’s better to follow the recommended path to connect your external device(s) to your Mac.

The best (or least problematic) method for connecting external drives

  • Turn ON your Mac or MacBook
  • Plug in the USB cable into the Mac and to the device
  • Do not use a hub–plug your drive directly into your Mac’s port
  • THEN Turn ON the external drive when the USB cable is connected

Using a hub? Think again

A lot of readers discovered that their older model hubs no longer worked in macOS. So check if the hub is the problem by plugging the external drive directly into the Mac.

If the drive is now recognized, the problem is likely the hub. First, try plugging the hub into a different port on your Mac.

If that doesn’t work, replacing it (if necessary) usually fixes the problem. Just make sure you purchase a hub that is compatible with the latest macOS and is self-powered (i.e. has a charger.)

Try a Super Slow Jam

Strange but true, some users found that their thumb drives work when they plug it in exceptionally slowly.

When they try and plug in the USB flash drive normally, their PC’s don’t recognize the disks.

But if they gently slide them into the port in slo-mo, their drives are recognized! Go figure.

The same trick works for all types of computers, Windows or Macs, Desktops or Laptops!

Power Problems

This error frequently occurs when the hard disk is not receiving enough power from the port. If you instead plug the drive directly into a power source (if a power supply is available for your drive,) the external drive usually mounts on its own now that it has sufficient and steady power.

If your drive doesn’t allow for an external power source, try connecting the drive to another USB port. Or plug it into a self-powered USB hub.

Often, our MacBooks don’t put out enough power across the built-in USB hubs and so adding a self-powered hub sometimes solves the problem straight away.

If your MacBook is not mounting an external hard drive or flash drive, try plugging in the power cable to the MacBook and reconnecting the drive. This tip often does the trick!

Rejecting the Ejecting

Another common reason is when you remove the drive without first ejecting. Instead of just pulling out drive connections, always perform a safe remove when ejecting external devices.

Options include right-clicking on the icon of your external drive and selecting “Eject device.”

Or just drag the drive icon to the Trash, changing it to an Eject symbol.

The rule of thumb for external drives is always to shut down, eject, or otherwise disable before unplugging.

This process means that the software “turns” it off before the hardware.

A Tight Fit is a Good Fit

Another reason for your Mac not recognizing external drives is a dirty or loose connection between your cable, USB-C multi-adapter, Thunderbolt 3, or other connecting ports.

So check your cable, your dongle (if used), any additional adapters, and the ports on both computers and drive to ensure that they are clear, clean, snug and fit tightly to each other.

Check that the cable connecting to the ports is indeed connected. Loose connections often lead to external drives not being recognized. Or even if they are recognized, they randomly disconnect without warning or prompting. A similar issue is frayed or worn cables, so make sure that your cable is in good condition.

If you use a hub for your connections, if possible try to connect your external drives directly into your Mac–no intermediary.

Check Your Settings

Sometimes it’s the simple things that trip us up. So before performing any complex troubleshooting, let’s look at some settings.

Go to Finder > Preferences.

Under both the General and the Sidebar tabs, see the section “Show these items on the desktop: (or sidebar:)”

Now verify that External Disks and Hard Drives have a checkmark in the box. If not, click it to enable your external drive icons to show on your desktop.

External hard drive won’t mount in macOS High Sierra or above?

When you are in Disk Utility, look in the upper-left corner and find the View option. Click on View, and you should get an option to Show All Devices.


How to reset NVRAM

Shut down or restart your Mac, turn it on and immediately hold down these four keys together: Option, Command, P, and R. Keep pressing these keys for a minimum of 20 seconds. It might look like your Mac restarts.

And if your Mac plays a startup chime when you turn it on, release the keys after hearing a second startup sound.

Also, you might reset the System Management Controller (SMC.) See these steps under the section “Does Your MacBook Shut Down When You Plug In Your External Hard Drive?”

Run Disk Utility

Open Disk Utility and see if your external drive appears here. Find Disk Utility in Applications > Utilities > Disk Utility. If your drive shows up but is not mounted, select the mount option which should mount that disk.

To verify, click on the Apple logo in your screen’s top left corner and select About This Mac. Select the Storage tab and see if your drive appears here.

If not, return to Disk Utility and select your external drive from the left sidebar.

Now choose First Aid or verify (repair) disk. This process should find and correct any minor errors with your drive.

Check Disk Format

If you can see your drive in Disk Utility but were not able to mount and use it, you might have a disk format problem.

Look and see if your external drive is listed as NTFS format, if so you want to reformat the drive using the erase function in Disk Utility and format it as exFAT, FAT, APFS (if supported) or Mac OS Extended.

Look at Your System Information

Let’s go to System Information and see all the USB devices connected to your Mac. Navigate to the Apple in the upper menu > About this Mac > Storage

For more details, go to the Apple Menu> About this Mac > and select System Report below the information about your Mac and its OS.

Terminal to the Rescue!

If System Information recognizes your USB external drives, but they continue not to show up, try disconnecting them and then remount the drives via Terminal.

  1. Find Terminal in Applications > Utilities > Terminal.
  2. Once open, type in the command diskutil list

The diskutil list command displays basic information about all available volumes and drives attached. So it’s a good command to use when checking if drives are really connecting to your computer.

Once you type in the command, you see a list of all your disks.

Look for the section labeled /dev/disk_ (external, physical).

The disk_ part is the physical disk identifier, and the underscore is whatever number or digit is assigned to this drive–make a note of that whole line including the numbers or digits following the word disk.

For partitioned drives, an “s” follows the disk identifier. The number following the letter “s” represents the partition number.

So, if a disk has two or more partitions, the total disk identifier looks something like this:

  1. disk3s1
  2. disk3s2
  3. disk3s3

Now, put in another command into Terminal diskutil info disk_. Make sure to add the number or digit assigned to this drive at the end, in place of the underscore.

For example, my external thumb drive is listed as /dev/disk4 (external, physical) so I type in the command diskutil info disk4. This command opens up detailed information about the drive, including its manufacturer name, the size, if it’s removable and further facts.

Once you establish that the drive is known by your system, use Terminal to eject that disk through the command diskutil eject disk _.

Remember to use the disk identifier number that associated with your drive in place of the underscore. Once you execute that command, type in diskutil list again to see if your disk is now gone from that list.

Once the drive is gone, physically remove it from your computer and then reinsert it — hopefully, your drive mounts and works as usual.

Terminal commands not working or seeing “operation not permitted” in macOS Mojave and above?

Mac Won T Recognize Seagate External Hard Drive

If your Mac is not allowing you to enter and execute Terminal commands, you need to grant the Terminal app full disk access.

Please see this article for details on how to grant the Terminal app access to your full disk.

Does Your MacBook Shut Down When You Plug In Your External Hard Drive?

This happens when your hard drive draws too much power or an ‘incorrect’ amount of power from the USB. Your Mac’s SMC shutdowns the computer to protect itself.

If this happens frequently, connect the drive to its own power source if possible, so it’s not siphoning power from the USB port.

If that’s not feasible (like thumb drives), try a different USB port or if applicable, a different USB cable. Also, reset your Mac’s SMC.

Resetting SMC

If the battery is nonremovable

  1. Shut down and unplug the power adapter
  2. Press Shift-Control-Option on the left side of the keyboard AND press the power button at the same time. Hold these keys and the power button for 10 seconds
    1. If you have a MacBook Pro with Touch ID, the Touch ID button is also the power button
  3. Release all keys and reconnect your Mac to the power adapter (plug it into an outlet)
  4. Press the power button again to turn on your Mac

If the battery is removable

  1. Shut down your Mac and disconnect the power adapter
  2. Remove the battery
  3. Press and hold the power button for 5 seconds
  4. Return the battery and reconnect your Mac to the power adapter (plug it into an outlet)
  5. Push the power button to turn on your Mac

Inspect with Console

For most of us, Apple’s Console app is a confusing list of logging messages and errors that make sense to an everyday user. But in times of trouble, Console is really quite useful, especially when you can’t figure out what the heck is going on!

In a nutshell, Console displays log information that helps you or a service provider troubleshoot problems on your Mac. Console won’t fix the problem, but it does provide information to diagnose the problem.

It’s never been easy to work with Console, but the good news is that starting with macOS Sierra, Apple retooled Console to make it a bit more user-friendly or at least DYI technician friendly.

So, let’s use Console to check that your USB port is detecting your devices. Find Console in Applications > Utilities > Console.

The console utility lets you know if your external USB devices are detected and if there are any errors. Before you attach your USB drive, open Console and select the Error and Faults Tab, now plug in the drive and look to see if it detects your device or if there’s an error.

If Console shows that nothing happened and no errors pop up, then your problem is not the USB device.

External Drives Very Slow after macOS Update?

Many readers have recently reported that they are experiencing slow down issues with their external drives after updating to macOS Catalina or Mojave.

If you are experiencing issues with your external drives after updating to macOS Mojave, your best bet is to reset the SMC and then try connecting to the external drive.

Reset SMC on MacBook

  • To do the SMC reset, start with Shutting down the Mac.
  • Press Shift-Control-Option on the left side of the keyboard, then press the power button at the same time.
  • Hold these keys and the power button for 10 seconds.
  • After the 10 seconds, release all keys. Then press the power button to turn the Mac on.

Resetting SMC on Mac Mini

  • If you are using a Mac Mini, simply shut down the Mac.
  • After your Mac shuts down, unplug the power cord.
  • Wait 15 seconds then plug the power cord back in.
  • Wait another 5 seconds, then press the power button again to turn on your Mac.

Now, try to connect the external drive and see if it is more responsive to your Mac.

Let’s Have a Third-Party

A lot of Mac users and lovers recommend using the third-party app Kext Utility to solve their problems recognizing external drives. Readers who could not mount their USB 3.0 and 2.0 FAT and FAT 32 External Drives on their Macs ran the program Kext Utility and after rebooting these USB drives worked!

Kext Utility runs on Mac OS X 10.5 or later. For macOS users, make sure you run the latest version.

Wrap Up

Sadly, Macs not recognizing external drives is nothing new. It’s a perpetual problem, especially after updating your Mac’s operating system to the latest macOS or OS X. But the good news is that quite a few solutions are available to fix this temporary issue (hopefully, it’s just that!)

Reader tips

  • If you use a hub for multiple external drives, try removing your hub or switching to a different (and newer model) hub. For me, when I used my hub, my drives didn’t show up or work. But when I plugged the disks directly into the iMac via USB, everything worked fine! No matter what I did, the hub would not work. So I purchased and installed a new multi-port hub (self-powered) and everything is working again. As an FYI, this happened after updating to macOS Mojave and even Apple Support could NOT identify the problem or explain why the hub that worked with High Sierra stopped working after the update to Mojave
  • I need to update my external disk’s driver. So you might want to contact the external drive’s manufacturer support department and see if there is an update for that drive and for the macOS or Mac OS X version you use
  • Go to System Preferences> Spotlight and deselect everything that shows up in that list. After you untick all the boxes, plug in your external drives. Once your external drive(s) is recognized, go back to System Preferences > Spotlight and set it back to the default spotlight search preferences by ticking all the boxes
  • Solved the problem by going to Preferences within Disk Utility and checking “Automatically Open Read-Only Images.” It turns out my USB thumb drive was read-only because it’s natively formatted as NTFS. That particular preference was off and prevented the drive from even showing up. Just do a quick reformat (if nothing is on the drive or nothing important), and all is well
  • If you changed your Mac’s system icons as Trav did, the solution is relatively simple and involves changing icons back to normal

For most of her professional life, Amanda Elizabeth (Liz for short) trained all sorts of folks on how to use media as a tool to tell their own unique stories. She knows a thing or two about teaching others and creating how-to guides!

Her clients include Edutopia, Scribe Video Center, Third Path Institute, Bracket, The Philadelphia Museum of Art, and the Big Picture Alliance.

Elizabeth received her Master of Fine Arts degree in media making from Temple University, where she also taught undergrads as an adjunct faculty member in their department of Film and Media Arts.

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Question:External hard drive not showing up on Mac”

“My external hard drive is plugged into my USB port. When I plug it in it starts running and the power light is on but I don't hear the usual noise that sounds when you plug something into the USB ports and it is not showing up.”

-A question from reddit

Have you ever been in a situation where Seagate, Western Digital, PS4, or Buffalo external hard drive connected with the Windows or Mac PC do not appear on your device? The scenario will break your peace, particularly when you have important files in it. How to fix an external hard drive not working on Mac? Try not to stress; this article will give you detailed guidelines on the most proficient method to get the issue settled.

You can figure out how to fix Mac not reading external hard drive and retrieve lost data from the hard drive after going through this article. Even if you don't have the foggiest idea where to begin, we are here to help. Relax and follow our article to check the connections, macOS settings, and the external hard drive. After doing so, you will find external hard drive Mac and it will hopefully appear on Mac once more.

Part 1: Why My External Hard Drive Not Showing up on Mac?

You may ask why the external hard drive not showing up Mac. Some internal or external subjects can bring about this issue and make my external hard drive searchable on Mac:

  • The external hard drive segment may have got corrupted.
  • It may have been formatted incorrectly.
  • The data system is damaged.
  • The drive problems happen in Windows or Mac PCs.
  • The USB port is dead.
  • The connecting cables might be faulty.
  • The hardware and software on your device may need an update.

You can attempt to link the hard drive to another PC or connect it with other USB ports. If every technique does not work, you can follow the instructions in this article to fix the Mac not recognizing external hard drive. In this way, you can recover lost data from an external hard drive with Tenorshare 4DDiG Data Recovery Software.

Part 2: How to Fix External Hard Drive not showing up on Mac?

If you follow the accompanying steps, you will recognize the cause and fix the issue that is preventing your external hard drive not showing up Mac.

Fix 1: Check the connecting cable

The principal or primary thing to do is to watch that it's connected, but the issue may be with the cable, however. One of the fundamental reasons why drives neglect to mount is if the drive isn't accepting sufficient power. Older Mac versions may require a USB power cable that parts into two USB connectors to convey adequate power to the drive.

Have a go at using an alternate cable with the drive to check whether that fixes the issue. Additionally, watch that the port on your Mac isn't the issue. Try connecting to an alternate port.

Fix 2: Try another Mac and afterward attempt a Windows PC

The following stage is to have a go at connecting the drive to another Mac. If it likewise neglects to mount there, you will realize that there is an issue with the drive.

The consequent step is to have a go at connecting the drive to a Windows PC. If the Drive mounts on PC, you have found what the issue is: the hard drive is designed for Windows PCs and can’t be used by your Mac.

Fix 3: Change your preferences

To change the preferences on your Mac

  • Open the Finder by clicking on Finder in the menu at the top of your mac screen
  • Pick Preferences go to General and ensure that there is a tick right next to External Drives

If the tick were already there, the external drive would show up. If the problem persists, keep reading to find more solutions.

Fix 4: Use Disk Utility to get to the drive

After the different checks above show that the disc is broken, you can utilize Apple's Disk Utility program to fix whatever is causing the issue. If external hard drive not showing up Mac disk utility, this is what to do:

Find Disk Utility by opening Spotlight (cmd+Space-bar) and type Disk Utility; press Enter to open the program.

There are three choices for you there:

  • First Aid: Checks the disc for errors and afterward fix the disc if necessary
  • Erase: Erases all the data available on the drive.
  • Restore: Permits you to delete the hard drive data and replace that with data from elsewhere.

Select the First Aid on the top and then click Run to verify this action.

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Fix 5: Change the Drive Format

If your Mac still can't fix the disc, it might be damaged, and if so, you need to ensure Macs and PCs can detect your drive. It would help if you formatted it with exFAT or FAT32.

Fix 6: The external Hard Drive is APFS Formatted

If your external hard drive not mounting Mac and it is APFS formatted, you are encouraged to refresh your macOS so it can work with the most recent systems. To refresh macOS, you can:

Step 1: Right-click the Apple logo at the upper right, and afterward, open System Preferences.

Step 2: Find and open Software Update to check for new operating system updates.

Step 3: Back up your necessary documents and follow the wizard to refresh your OS.

Part 3. Recover Data from External Hard Drive not showing up with 4DDiG

When nothing could resolve the external hard disk not detected Mac issue, you can select Tenorshare 4DDiG for Mac Data Recovery to retrieve lost data from your hard drive. The Tenorshare 4DDiG Data Recovery for Mac can likewise detect devices that were unrecognizable by your Mac. Media player, advanced camera, USB drive, or HDD/SSD, Tenorshare can retrieve data from any medium. It is secure and has an extraordinary success rate. You need to follow these steps:

    Secure Download

  • Step 1: Select a Location
  • Open 4DDiG Mac Recovery Software after installing and select an area like your hard drive to begin the Mac data recovery process. At that point, click 'Scan' to search for every lost record.

  • Step 2: Scan and Preview
  • The Tenorshare 4DDiG Software will take some time to check all erased files. After the result is created, you can tap on explicit document types to see more details.

  • Step 3: Recover Mac Files
  • Click on any file you want to recover and select the 'Recover' button and select a destination to save discovered files. It is not a good idea to save the recovered files back at the location where you lost them.

  • Step 4: That's it. All of the lost files on your external hard drive shall be recovered now.

Part 4. FAQs about Hard Drive Not Showing up on Mac

1. How to connect your hard drive to Mac?

Connecting the drive to your Mac is not a challenging task to pull off. Plug the hard drive into the Mac utilizing the cable that was provided with it. Most hard drives use USB for connection, so you will have to plug the USB cable into an open port on your Mac. You can always find one USB port along each side of the Mac.

2. Do all hard drives work with Mac?

All external hard drives may work with PCs or Macs, as long as the connectors are there (Firewire, USB, and so forth). It does not make any difference how the drive is formatted initially since you can re-design any way you like. Formatting in HFS (Mac OS Extended) or FAT32 or NTFS-3G should be possible with the Mac OS X Disk Utility.

3. Do I need a particular external hard drive for Mac?

In general, you need not bother with amazing Mac-only hardware stuff any longer. Hard drives, RAM, peripherals, and so on are compatible on a large scale. Even the stuff that is generally seen as 'Macintosh' (i.e., FireWire and now Thunderbolt) is Windows-and Linux-workable and will normally turn out great.

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Fix External Hard Drive not Showing up on Mac and Recover Data

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Mac Won't Recognize Seagate External Hard Drive For Mac

It is sometimes very complex to look at why an external hard disk not detected Mac. If you are stressed over data loss in this situation, you can get your data back from the external hard drive by using Tenorshare 4DDiG Data Recovery for Mac.