A Few Words Written Before
The external hard drive is not showing up on Mac probably because of hard drive corruption. So it's important to recover lost data before you learn why and how to fix when you can't see external hard drive/USB drive/SD card on the Mac. To prevent data loss, you can free download iBoysoft Mac Data Recovery in macOS Catalina/Mojave/High Sierra, and get data off your drive first.
If you connect an external hard drive to Mac but it is not showing up, don't be panic because you have a great chance to fix this issue by checking connections, macOS settings, and imperatively, the external hard drive itself. Don't know where to start? Take it easy as we are here to help you troubleshoot and give professional solutions to repair the hard drive not showing up issue.
Now, let's plunge into details.
Why isn't an External USB drive Showing up on Mac?
Normally, when you insert an external hard drive in your Mac computer, it will appear on the desktop or in the left-hand column of Finder. But what if you plug the external hard drive into your Mac but nothing happens? Does this mean your Mac not recognizing the hard drive? Probably not.
The causes for external hard drives, USB drives, and SD cards not showing up on Mac are varied. Namely, it could be a faulty connection like broken USB cable and malfunctioned USB port, the card reader may not be working properly, the external hard drive may have been formatted incorrectly, the hardware and software may need an update, the file system of the external hard drive may be corrupted, and so forth.
Therefore, it's necessary to follow our step-by-step guide to fix this issue so that you can see this storage device working on your Mac again.
1. Check the Connections of the External Hard Drive
Most external hard drives, including Buffalo Ministation, WD, Samsung, Seagate, Lacie, are connected to Mac using USB cables and ports. If any part of the connections fails, your external drive won't show up on Mac.
So, check if the external hard drive is properly connected by the following steps.
Step 1: Check the power connections
Since external hard drive requires electricity to light up, spin, and transfer data, so the first thing you need to check is that, if the external is not showing up on Mac because of lack of power.
- 1. If you are using a Desktop external hard drive like Seagate Backup plus and WD Elements Desktop, make sure the external hard drive is extrally connected to a power socket.
- 2. If you are using portable external hard drive whose power is supplied by USB port, make sure the USB socket is not wobbly, dusty, loose, or deformed. Also, you should check if the USB port is supplied with enough power by connecting another hard drive to this port.
- 3. If you are working on MacBook, MacBook Air, and MacBook Pro models, you need to pay more attentions on two things. One is that if the external hard drive is not showing up on Mac due to low power mode, because external can't work if there is no enough power in the USB port. The second is that if your Mac uses Thunderbolt 3 or USB-C port and you reach your external hard drive via USB-C adapter, make sure the USB hub and adapter works well. What's more, an authentic and reliable USB Type C adapter is better for power and data supply.
Step 2: Check the other connections
When your external hard drive, for instance, a Seagate hard drive is not recognized by Mac, the second part coming into sight is if the external hard drive is well connected for data transferring. So, If your external hard drive lights on but is not detected or showing up, try these things.
- Check if the wire of external the hard drive is broken.
- Try to connect it to another Mac or even a PC. Possibly, it's just an incompatible USB driver that stops your hard drive working.
- Check the USB port on hard drive enclosure case. A good disk enclosure allows your drive to communicate with computers efficiently, supplying power and data access. So if necessary, you can ask help from specialists to open the external hard drive case and have a check.
2. Check Programs or Applications Installed on Your Mac
Chances are that some programs are stopping your external hard drive being loaded. In this case, you can try to reboot your Mac in Safe mode, which only runs essential macOS items.
- Step 1: Restart your Mac (some Mac computers play a startup sound).
- Step 2: Immediately press and hold the Shift key, and then release the Shift key when you see the progress indicator.
- Step 3: After the restart, reconnect your external hard drive to the Mac and see if it is recognized. If the external hard drive is recognized by macOS in Safe mode, you should start your Mac in normal mode and uninstall the suspicious programs that you download recently.
3. Check if the Mac is Set to Show Connected External Drives
Another common reason for external hard drive not showing up is that the Mac is not set to. If you can't see the external hard drive on the desktop and in the finder of macOS Catalina, Mojave, or earlier, the following steps would be helpful.
- Show the external hard drive on the desktop: Go to Finder > Preferences > General tab and select "External disks" to make external hard drives show on the desktop.
- Show external hard drives in Finder: Go to Finder > Preferences > Sidebar and make sure the "External disks" under "Locations" is ticked. Then your external hard drive will appear in Finder.
4. Access the External Hard Drive by /Volumes/ Folder
If the external hard drive is not showing up on Mac as usual, where else you can find the hard drive? In fact, you can try your luck by checking the /Volumes/ folder. Most of the time, Mac will show connected and mounted volumes there.
- Step 1: Launch Finder and click Go in the top menu bar > Go to folder.
- Step 2: Then type /Volume/ and hit Enter.
- Step 3: Then you can see the volumes folder that lists all mounted drives and disk images. If your external hard drive is listed, access the hard drive and get to your files there directly.
5. Check Whether the External HDD Can be Found in Disk Utility
To make sure whether your external hard drive is detected by macOS, you can go to Applications > Utilities > Disk Utility and check if the external hard drive is showing up on the left side.
Note: If your external fusion drive is not showing up on Mac, you can check if it is recognized as two separate drives by macOS in Disk Utility also.
There are two possible circumstances:
- The external hard drive could be showing up in Disk Utility but greyed out.
- The external hard drive doesn't show up in Disk Utility.
First, let's take a look at what we can do if the external hard drive is showing up in Disk Utility.
Step 1: Check if the external hard drive is mounted
If the external hard drive can be found in Disk Utility, it means that your external hard drive is detected by your Mac. But since you can't see and open your hard drive as usual, we need to confirm more information displayed in Disk Utility.
- 1. Expand the View option and choose Show All Devices.
- 2. Find and select the external hard drive that is not showing up on your Mac.
- 3. Choose Mount at the top menu bar.
However, if no partition is showing up but the manufacturer's name like WD and Seagate, the partition table (A unit of data describing the partition information on the hard disk) may be damaged or lost. As a result, macOS is unable to recognize the external hard drive. In this situation, you're advised to recover important data with iBoysoft Mac Data Recovery first, and then reformat this hard drive.
Step 2: Check if the file system of the external hard drive is recognizable
The file system manages how and where data on a storage disk is stored, accessed and managed. So it's crucial to make sure that the file system is not corrupted and it is doing a good job.
To check the file system in Disk Utility: simply select the drive you want to check, and then the disk information, including file system and storage capacity, would be displayed at right.
There are 4 possible circumstances:
First: The file system is corrupted and you are unable to mount this external hard drive on Mac
The file system could be damaged due to improper ejection or bad sectors. To repair this corrupted external hard drive, First Aid on your Mac is a great disk repair tool to use.
- 1. Launch Disk Utility.
- 2. Choose the grayed out external hard drive from the left sidebar.
- 3. Click the First Aid button on the top and then choose Run to confirm this operation.
If First Aid failed to repair the external hard drive, the file system or some core data is too corrupted to be repaired by First Aid. So, you have to reformat it to assign a new file system to this hard drive.
- What to do when Disk Utility reports invalid content in journal?
- What to do when Disk Utility reports invalid volume directory file count?
But as it was pointed out before, reformatting will clean the external hard drive and erase your data on this drive. If you don't have any backup and don't want to lose the data, you are advised to recover data from the corrupted external hard drive with iBoysoft Mac Data Recovery.
iBoysoft Mac Data Recovery is powerful in hard drive data recovery, especially when your Macintosh hard drive or external hard drive is not showing up or not recognizing on Mac. It helps you recover data from unreadable, unmountable, corrupted, and formatted drives. Except for hard drives, this software data recovery also works with USB flash drives, memory cards, SD cards, pen drives, CF cards, etc.
To recover data and reformat the corrupted external hard drive:
- 1. Download and install iBoysoft Mac Data Recovery on Mac.
- When external hard drive is not showing up on Mac due to disk corruption, the data on the drive becomes a great concern. To recover and get to your files, iBoysoft Mac Data Recovery is a handy tool.
- 2. Scan for lost data on the external hard drive.
- After launching this program, you can see the unrecognizable/corrupted external hard drive is listed in the main interface. To search for your files on this drive, click on Scan to continue.
- 3. Preview the searching results, choose files you need, and click Recover to get them back.
- When you can't open the external hard drive on your Mac, you can use the Preview feature of iBoysoft Mac Data Recovery to make sure your documents, photos, music files, videos, and emails are in good condition.
- 4. Launch Disk Utility and locate the external hard drive from the left sidebar of the window.
- 5. Select this external hard drive and click the Erase button.
- 6. Complete the related information (name, format, scheme), then click Erase to reformat this problematic hard drive.
Second: The external HDD is APFS formatted
If your Mac uses macOS 10.12 or earlier but external hard drive is APFS formatted, you are advised to update your macOS so that it can work with the latest file systems, software, as well as some firmware relating to USB peripherals and devices.
To update macOS, you can:
- 1. Right-click the Apple logo at top right, and then choose System Preferences.
- 2. Find and open Software Update to check for new macOS update.
- 3. Back up your important files and follow the wizard to update your operating system.
Third: The external hard drive is Windows NTFS formatted
Even though Mac can recognize NTFS drive, you can only read NTFS without write permission. And some times, the external hard drive will not work properly. In this case, you have two options:
- If you need to use this NTFS external hard drive both for Mac and PC, you can install an NTFS for Mac program to fix this issue without reformatting.
- If the external hard drive is used only for Mac, you can back up your important files and then reformat it to a compatible file system like HFS, FAT32 or exFAT.
Fourth: The external hard drive is formatted with non-native file system
Other file systems like Linux EXT3 and EXT4 would not be readable by Mac. The only solution is to reformat it to make it compatible with your Mac.
Warning: Any operation relating to "Erase" and "Format" would wipe files off your storage devices. So make sure you have a copy of the data, or you can recover files from this external hard drive with iBoysoft Mac Data Recovery.
The solutions above are prepared for external hard drive showing up in Disk Utility on Mac. Nevertheless, what if the external hard drive is not showing up in Disk Utility at all?
Don't worry, we still have some fixes for external drive not showing up in Disk Utility
Step 1: Find invisible external hard drive in System Information
If the external hard drive doesn't show up in Disk Utility, it's possible that the drive has encountered hardware issues. You can check the hardware information in System Information: Go to Applications > Utilities > System Information > USB, and then check the external hard drive information.
If you see the external hard drive showing up there but not in Disk Utility, the hard drive may be under repair by macOS. Go and check it the Activity Monitor.
- 1. Click the Launchpad and find the Other folder. Find and open Activity Monitor there.
- 2. Type and search if there is any process named "fsck_hfs" or something similar. (If your external hard drive is exFAT formatted, then it should be "fsck_exfat".)
- 3. Select that task and click the Force a process to quit button at the upper left to stop it. and Then the external hard drive should show up on the desktop of your Mac.
If the parameters of the external hard drive are not recognized correctly or even not recognized, you can move forward.
Step 2: Reset your Mac's NVRAM
NVRAM is helpful to retain the information while power is turned off. If you experience issues related to these settings or others, resetting NVRAM might help.
- 1. Shut down or reboot your Mac.
- 2. Immediately press these four keys in a sequence: Command + Option + P + R.
- 3. Hold the keys for at least 20 seconds and after you hear the second chime, release the buttons.
- 4. After releasing the keys, your Mac will restart and hopefully your drive will show up.
Step 3: Reset the SMC on your Mac
In certain circumstances, resetting SMC can be a solution because SMC is responsible for lower-level functions like power and hardware.
Note: The method of resetting SMC is varied from models to models, so check and know how to reset the System Management Controller (SMC) on your Mac.
Let's take resetting SMC of a MacBook Air, MacBook Pro Retina, or MacBook Pro's with an internal non-removable battery as an example:
- 1. Shut down your MacBook Air/MacBook Pro.
- 2. Connect the power adapter to the Mac.
- 3. After your Mac shuts down, press Shift + Control + Option on the left side of the built-in keyboard, then press the power button at the same time. Hold these keys and the power button for 10 seconds.
- 4. Release all keys and the power button at the same time. Then press the power button again to turn on your Mac, which would take a little time.
Step 4: Run Mac diagnostics to detect hardware issues
Apple Service Diagnostic is a set of diagnostic tools used by technicians to find faults. You can use it to confirm or deny your suspicions. If the external hard drive has been physically damaged, you have to send it to local disk repair center.
- 1. It is advised to disconnect all the external devices except keyboard, mouse and other useful devices.
- 2. Reboot your Mac or you can power on your Mac if it powers off.
- 3. Press and hold D button on your keyboard. Hold the button until you would be asked to choose the language.
- 4. After selecting your language, it will display a progress bar stating Checking your mac.
- 5. After completing the diagnostics, it will suggest you the solutions for the errors diagnosed.
To sum up
It's relatively complicated to check out why is an external hard drive not showing up/recognized/detected by macOS. If you worry about data loss in this process, you can recover all important data from the external hard drive first with the assistance of iBoysoft Mac Data Recovery.
Moreover, to prevent an external hard drive not showing up issue, it's advised to properly eject or connect your external drives at any time. Besides, always back up critical files on another drive or in the cloud.