How can I check a USB flash drive or memory card for errors and repair them?

You can check a USB flash drive or memory card for errors and repair them using the following methods:Run a disk check: On Windows, you can use the built-in CHKDSK tool to scan and repair errors on the drive. Open a command prompt window and type 'chkdsk X: /f' (replace X with the drive letter of your USB flash drive or memory card) and press Enter. This will scan the drive for errors and attempt to fix them.Use a third-party disk repair tool: There are several third-party disk repair tools available that can help you scan and repair errors on your USB flash drive or memory card. Some popular options include EaseUS Partition Master, MiniTool Partition Wizard, and DiskGenius.Format the drive: If the above methods do not work, you can try formatting the drive to fix any errors. Keep in mind that formatting will erase all data on the drive, so make sure to back up any important files before proceeding.Use a different computer or USB port: Sometimes, the issue may be with the computer or USB port you are using. Try connecting the USB flash drive or memory card to a different computer or USB port to see if the issue persists.Check for physical damage: If the drive is physically damaged, such as a broken connector or cracked casing, it may not be repairable. In this case, you may need to replace the drive.By following these steps, you should be able to check a USB flash drive or memory card for errors and repair them if possible.

Is it possible to recover data from a damaged storage device without specialized software?

It may be possible to recover data from a damaged storage device without specialized software, but it can be more difficult and time-consuming. Some methods that may be used include connecting the damaged device to a different computer, using file recovery tools that are built into the operating system, or manually extracting the data by opening up the device and accessing the storage components directly. However, using specialized software designed for data recovery is typically the most effective and efficient way to recover data from a damaged storage device.

What are the possible causes of damage to a USB flash drive or memory card?

Physical damage: Dropping, bending, or crushing the USB flash drive or memory card can cause damage to the internal components.Water damage: Exposure to water or other liquids can cause a short circuit and damage the device.Electrical damage: Plugging the USB flash drive or memory card into a faulty or incompatible device can cause electrical damage.Overheating: Exposing the device to high temperatures or leaving it in direct sunlight for an extended period of time can cause damage.Data corruption: Removing the USB flash drive or memory card from a device without safely ejecting it first can lead to data corruption and potential damage to the device.Malware or virus infection: Connecting the USB flash drive or memory card to a infected computer can introduce malware or viruses that can damage the device.Manufacturing defects: In rare cases, the device may have a manufacturing defect that causes it to malfunction or become damaged.

Why doesn't my Mac recognize my USB flash drive or memory card?

There could be several reasons why your Mac is not recognizing your USB flash drive or memory card. Some possible reasons include:The USB port or memory card slot may be damaged or faulty. Try using a different port or slot to see if the device is recognized.The USB flash drive or memory card may be formatted in a file system that is not compatible with Mac. Try reformatting the device to a compatible file system such as exFAT or FAT32.The USB flash drive or memory card may be corrupted or damaged. Try using the device on another computer to see if it is recognized.The USB flash drive or memory card may not be properly inserted into the port or slot. Make sure the device is securely connected to the Mac.The Mac's operating system may need to be updated. Check for any available software updates and install them to see if that resolves the issue.If none of these solutions work, it is possible that there may be a hardware issue with the Mac itself. In this case, you may need to contact Apple support or take the Mac to an authorized service provider for further assistance.

What should I do if the system prompts me to format the flash drive?

If the system prompts you to format the flash drive, it means that there may be a problem with the drive or the files on it. Before proceeding with formatting, try the following steps:Backup your data: If you have important files on the flash drive, make sure to back them up before formatting. You can copy the files to another storage device or cloud storage.Check for errors: Run a disk check on the flash drive to see if there are any errors that can be fixed without formatting. You can do this by right-clicking on the drive in File Explorer, selecting 'Properties,' then going to the 'Tools' tab and clicking on 'Check.'Scan for viruses: It's possible that the flash drive is infected with malware, which is causing the system to prompt for formatting. Run a full antivirus scan on the drive to check for any threats.Try on another computer: If the prompt to format persists, try connecting the flash drive to another computer to see if the issue is with the drive or the computer.If none of the above steps resolve the issue and you still need to format the flash drive, proceed with caution. Formatting will erase all data on the drive, so make sure you have backed up any important files. To format the drive, right-click on the drive in File Explorer, select 'Format,' choose the file system and allocation unit size, and click 'Start.'

How to Recover Data From a Damaged USB Stick or Memory Card in MacOS

Author: Vladimir Artiukh
Editor: Oleg Afonin
Updated: 11.04.2025 11:16

Read this article to find out how to repair a damaged USB stick or memory card on Mac. How to retrieve files from a drive if it isn’t displayed in Finder, and how to recover deleted data from USB drives and memory cards.

How to Recover Data From a Damaged USB Stick or Memory Card in MacOS

Contents

How to check drive operability
- Step 1. Checking connection
- Step 2. Check and repair your drive with Disk Utility
How to create an image of a USB stick or memory card in MacOS
- Method 1: Hetman Partition Recovery
- Method 2: Terminal
Recovering data from a damaged USB stick or memory card in MacOS
- Method 1. How to recover data from the disk image
- Method 2. How to recover deleted data from USB stick or memory card with Hetman Partition Recovery
How to restore operability of a USB stick or memory card
Conclusion
Questions and answers
Comments

USB sticks and memory cards are very convenient devices to store and transfer data. The only problem is, they have a nasty habit of getting out of order when you least expect it. It often happens due to file system errors, because the devices were removed incorrectly, or even after some physical damage.

We’ll explore a few methods to retrieve information from a damaged USB stick or memory card. How to get your files from a drive which is not displayed in the Finder, and how to recover deleted data from USB drives and memory card.

Go to view

MAC Can’t Detect an External Drive

How to check drive operability

Step 1. Checking connection

The first step to take is to make sure that the problem comes from your device, and not from the USB port or card reader.

To do it:

Connect the device to another USB port. If your Mac lacks the required ports, use adapters (for example, USB to Type-C).
If you work with a memory card, try using another card reader. If it’s connected to your computer with a cable, check this cable for damage.
Connect your USB stick or card reader to another computer. If your device works well with another Mac, then your computer or laptop might be the actual culprit.

If the device is not recognized, you can move on to the next step.

Step 2. Check and repair your drive with Disk Utility

The next step will help you see if the operability of your device can be restored, and we can try to repair its errors.

To check the status of your USB stick or memory card, let’s use a MacOS integrated tool called Disk Utility.

Press the keyboard shortcut – Command + Space, and type “Disk Utility”; otherwise, open the tool from Launchpad – Other.

In the menu on the left, find the drive you need. If it’s not displayed, try reconnecting the drive – remove it and plug it in your Mac again.

Disk Utility: In the menu on the left, find the drive you need

Now select the device and click on First Aid. The tool will run disk diagnostics, checking its structure and file system.

Disk Utility: Now select the device and click on First Aid

If any errors are detected, the tool will suggest repairing them. If such request appears, confirm this action.

This utility will help you fix many common problems automatically – such as damaged file system or wrong metadata entries.

Disk Utility: If any errors are detected, the tool will suggest repairing them

How to create an image of a USB stick or memory card in MacOS

Before we proceed to other steps in troubleshooting your device, it’s recommended to create a byte-for-byte image of the USB stick / memory card. This will allow you to work with the data safely, without the risk of losing or damaging it.

Method 1: Hetman Partition Recovery

To create a complete image of any disk, use Hetman Partition Recovery – a dedicated data recovery tool. Download it from the official website, choosing the version for MacOS.

Partition Recovery™ 5.0

The tool recovers data from any devices, regardless of the cause of data loss.

Download

Option	Supported by Hetman Partition Recovery
Recovering macOS file systems (HFS+, APFS)	✅ Yes
Recovery from disks formatted in macOS	✅ Yes
Recovery from external disks used in macOS	✅ Yes
Supported file systems	FAT/exFAT, NTFS/ReFS, APFS/HFS+, Ext2/3/4/ReiserFS, and XFS/UFS/ZFS/Btrfs/VMFS/HikvisionFS
Supported operating systems	MacOS, Linux, Windows

Install the program. Here’s how you do it:

Run the downloaded file by simply double-clicking on it.
Drag the shortcut to the folder containing your programs.
To run the tool you may have to enter your account password.
When the tool is launched, you can see that it needs full access to your disks to work properly. Open the Security Settings and enable full disk access.
When the tool window opens, find the required drive, select it and click Save Disk – Full, and choose where to save it.

When the process is over, you’ll get a byte-for-byte image of your USB stick or memory card. Now you can experiment with your drive as long as it takes, since you can recover its files from the image at any time.

Method 2: Terminal

Also, such image can be created with the Terminal. Open it from the App menu.

For starters, you need to know the USB stick or memory card identifier. To do it, run the command diskutil list.

diskutil list

Then run this command to create an image:

sudo dd if=/dev/disk2 of=/Users/mac/Desktop/USB_Backup.img bs=1m

Here, the disk number is the identifier of your drive.

As a result, the image will be saved to your desktop.

Recovering data from a damaged USB stick or memory card in MacOS

Method 1. How to recover data from the disk image

Now that you have a disk image, I’ll show you how to retrieve the files you need.

To do it, open Hetman Partition Recovery and upload the disk image you have just saved.

Partition Recovery™ 5.0

The tool recovers data from any devices, regardless of the cause of data loss.

Download

In the Tools menu, select Mount Disk - RAW images. Give the path to the image - Open.

Hetman Partition Recovery: Mount Disk - RAW images

The disk will appear in the program window. Right-click on the disk and choose Open.

Hetman Partition Recovery: Open the mounted disk

Now select the scan type - Fast scan.

When the scan is over, go to the folder where the deleted files used to be, select them and click Recovery.

Hetman Partition Recovery: Select everything you want to restore, and click the Recovery button

Then choose where to save the items (the disk and folder) and hit Recovery again.

In the end, you will find the recovered files in the folder you have chosen.

Method 2. How to recover deleted data from USB stick or memory card with Hetman Partition Recovery

This recovery tool allows you to run an in-depth analysis on damaged devices, even if they are not recognized by your operating system, and recover deleted files. If you accidentally removed important files from a USB stick or memory card, such files can be recovered in the same way as you’ve just seen.

Two scan types are available:

Fast scan, which analyzes the disk in no time and displays the files it has found.
And Full analysis, which takes longer and goes deeper to search for files.

Hetman Partition Recovery: there are two scan types

At the next stage, select the file system of your drive. As you can see, the tool supports most popular file systems, and it can help you recover lost files from any kind of storage device.

When the selected scan is over, open the folder from which data was deleted. All deleted files are marked with a red cross.

You can see the contents of every file in the preview window.

Now - just like you did in the case with recovering files from an image - select the files you need to restore and click Recovery, then give the path where to save them.

As you can see, the program has no difficulty in finding the files that used to be stored on this USB stick, and recovering them. If there are no files in your folder, then the information about their location might have been erased, so try looking for them in the Content-Aware Analysis folder.

Hetman Partition Recovery: Content-Aware Analysis folder

How to restore operability of a USB stick or memory card

Step 1. Recovery with the Terminal

Now that we have explored how to create a disk image and recover its files, it’s time to move on and restore operability of your USB stick or memory card. For that purpose, we’ll need the Terminal.

Open the Terminal and type the following command:

diskutil list

This command will display the list of all disks connected to your computer. Find your USB stick on the list. Remember its identifier.

Now let’s check it for errors and fix them if possible.

Do it with another command:

Sudo diskutil repairDisk /dev/disk2

sudo fsck_msdos /dev/disk2

Specify the drive identifier here. As a result, if the system finds any errors, it is supposed to correct them automatically.

Wait until the process is over. When errors are fixed, the USB stick or memory card should start working properly.

Step 2. Repair MBR or GPT with the Terminal

If the problem is caused by the damaged boot record or partition table, you can also try fixing them with the Terminal.

Let’s use the following commands to get the job done:

To repair GPT, use this command:

gpt recover /dev/diskX
To repair MBR:

sudo fdisk -u /dev/diskX

In both commands, specify the number of the required disk.

Step 3. Creating a new partition with Disk Utility or Terminal

If your device is displayed in Disk Utility but it doesn’t work, try creating a new partition on it. To do it:

Open Disk Utility.
Select your device.
Click Erase and choose the format (for example, ExFAT).

Otherwise, run the following command in the Terminal:

diskutil eraseDisk ExFAT NEW_NAME /dev/diskX

Conclusion

Now you know that a damaged USB stick or memory card can be recovered successfully, with just a bit of effort applied.

However, we recommend removing your USB devices properly through the Finder or Disk Utility - just to avoid such situations. At the same time, keep in mind that important data should always be backed up.