You will or have already happened to have a USB key that no longer worked or was incomplete. Before throwing your key in the trash, try to see if it is a problem with reading data, formatting, or a purely physical problem. In the first case, there are repair utilities (for PCs and Macs). In the second case, you will have to reformat the drive after trying to recover what was in its memory, since formatting will erase all data. In the latter case, you (or a professional) will open the key and attempt to establish some kind of external USB cable connection to try and recover what may be. Needless to say that this latest intrevention requires you to be manual and know you in welding.
Steps
Method 1 of 3: Scan and repair a USB drive
Under Windows

Step 1. Plug your USB drive into your computer
The USB key is inserted into one of these rectangular ports located on the front panel of a central unit. If the content was not displayed correctly on the screen, despite inserting on each of the USB ports, check that the repair software and your drivers are up to date.

Step 2. Make the combination ⊞ Win + E
You will then run Windows File Explorer (

) which allows you to browse the files.

Step 3. Right click on your USB drive icon
A contextual menu then appears on the right.
- If the key does not appear, click on > beside This PC and it will be there as if by magic.

Step 4. Click Properties
This is the very last option in the wrench context menu.

Step 5. Click the Tools tab
In the top row of tabs, this is the second.

Step 6. Click Check Now
This is the only button, on the right, in the frame Error checks at the head of the window.

Step 7. Wait for Windows to finish repairing the volume
During the repair, you will have to validate certain instructions.
- You may be required, if there is a problem with the key to click a link, such as Analyze and repair.

Step 8. Click Close at the end
If the problem with your USB drive was non-hardware in nature, you should have a working drive.
Mac

Step 1. Plug your USB drive into your computer
The USB stick fits into one of these rectangular ports located on the back of the monitor (iMac) or on the side of the laptop (MacBook). If the content was not displayed correctly on the screen, verify that the repair software and your drivers are up to date.

Step 2. Open Finder
In your Dock, click the icon with two recessed faces.

Step 3. Click Go
This is the fifth menu in the general menu bar at the top of the screen.

Step 4. Click Utilities
This option is practically at the bottom of the menu Go.

Step 5. Double-click Disk Utility
Its icon is a stethoscope above a hard drive.

Step 6. Click once on the name of your USB drive
In category External, on the left, should appear the name of your key.

Step 7. Click on S. O. S
This option is the first on the left in the top row.

Step 8. Click Run when desired
In the window that appears, click on the blue button.

Step 9. Quietly wait for the volume inspection to complete
This utility is capable of repairing a number of software problems, unfortunately not all!

Step 10. Click Done when desired
If the problem encountered is detected by the utility, chances are it has been addressed, your key should work again.

Step 11. Click on the symbol

To remove your key without damaging its contents, click this symbol to the right of the key name in the Finder window. For the same result, on the Desktop, right-click on the wrench icon and select the second option (Eject [key name]).
Method 2 of 3: Reformat a USB flash drive
Windows

Step 1. Plug your USB drive into your computer
Insert it into one of the USB ports on your PC.

Step 2. Make the combination ⊞ Win + E
You will then run Windows File Explorer (

) which allows you to browse the files.

Step 3. Right click on your USB drive icon
A contextual menu then appears on the right.
- If the key does not appear, click on > beside This PC and it will be there as if by magic.

Step 4. Click Format
This option is at the start of the second half of the menu. The format window opens.

Step 5. Select a file system format
Click on the drop-down list File system and you will find three different formats there.
- NTFS: this is the default format of the Windows operating system. This format is only suitable for Windows machines.
- FAT32: it is an old format, but widely used, because it is very compatible (Windows and macOS). As the name suggests, the media should not exceed 32 GB.
- exFAT (recommended): This format works on both Windows and macOS and there is no limit to the capacity of the media.
- If the key is already formatted and you are sure it is not a hardware problem, then you can also check the box Quick format in the bottom frame titled Formatting options.

Step 6. Click Start, then on OK.
Windows then begins a formal formatting of your USB key.

Step 7. Click OK at the appropriate time
If this button appears, everything went well: your USB key is operational.
Mac

Step 1. Plug your USB drive into your computer
Insert it into one of the USB ports on your Mac.
Some computers no longer have a port, so you will need an adapter

Step 2. Click Go
This is the fifth menu in the general menu bar at the top of the screen.
If you do not see this menu, it means that you are not on the Desktop: click on an empty space on it or click, in the Dock on its icon (two recessed faces)

Step 3. Click Utilities
This option is practically at the bottom of the menu Go.

Step 4. Double-click Disk Utility
This utility is in the central window at the end of the list (alphabetical classification).

Step 5. Click once on the name of your USB drive
In category External, in the left column should appear the name of your key.

Step 6. Click the Erase tab
This option is the third in the row of tabs at the top of the window.

Step 7. Give your key a name
You can keep the same or change it. Once the formatting is done, this name will be the name of your key.

Step 8. Select a file system format
Use the drop-down list Format by right-clicking on the two arrows on a blue background. There you will find six different formats.
- Mac OS Extended (Journaled): this is the default format for Macs. Use it if your media is only intended for Mac machines.
- Mac OS Extended (Journaled, Encrypted): this is the default format for Macs, but encrypted.
- Mac OS Extended (Case Sensitive, Journaled): this is another version of the default format which is able to handle files with the same name, but written in a different case (file.txt and File.txt are two different files).
- Mac OS Extended (Case Sensitive, Journaled, Encrypted): it is a format which combines default format, case sensitivity and encryption.
- MS-DOS (FAT): it is a format managed by both Windows and macOS, but within the limit of a key not storing more than 4 GB.
- ExFAT (recommended): it is a format supported by both Windows and macOS, but unlike the previous one there is no limit on the capacity of the key.

Step 9. Click on one of the file system formats
For extended compatibility, click MS-DOS (FAT) Where ExFat.

Step 10. Click Clear
Click Delete a second time to confirm. Then begins formatting your key. When the operation is complete, the icon of your key with its name appears on the Desktop.

Step 11. Click Done
This is the last step that completes the formatting operation.

Step 12. Click on the icon

To remove your key without damaging its contents, click this symbol to the right of the key name in the Finder window. For the same result, on the Desktop, right-click on the wrench icon and select the second option (Eject [key name]).
Method 3 of 3: Repair a hardware problem on a USB flash drive

Step 1. Understand that the operation is delicate
Unless you're familiar with it, physically repairing a USB drive is anything but simple.
- If it is the data storage part that is damaged, it is advisable to call in a professional who will try, if not to save the key, at least to recover as much data as possible.
- The cost of data recovery varies depending on the professional, the state of the key, the type and amount of data stored. This can range from a few dozen euros to several hundred.

Step 2. Inspect the inside of the USB drive connector
It is a precaution that must always be taken before going to the big means. Your key may not work because of debris that has slipped into the bottom of the hollow connector. Try to see if this is indeed the case and gently remove it with a very sharp toothpick.

Step 3. Test your USB drive on another USB port or on another computer
Your key may be in perfect condition and the USB port is faulty.

Step 4. Collect some tools and supplies
The case of a broken connector is considered here. If you're willing to risk it all, you'll need the following tools:
- a soldering iron with soldering wire and soldering flux;
- an unused USB cable;
- wire cutters or strippers;
- a small flat screwdriver;
- a simple magnifying glass or jewelry.

Step 5. Unmount the case from the USB key
To do this, use the small screwdriver on the side of the wrench.

Step 6. Use a magnifying glass to inspect the printed circuit board (PCB) and solder points
If the printed circuit (green plastic part with copper paths) is damaged or if the solder points are really torn, it is best to call a professional.
The solder points unite the connector and different lines of the printed circuit. If the connector has just separated, totally or partially, from the assembly without damaging anything in appearance, continue reading

Step 7. Place your USB drive on a hard surface
Position the wrench so that the connector is towards you and the solder points are facing away.

Step 8. Cut the emergency USB cable with wire cutters
In the case of an adapter, make sure you cut the cable on the USB side.

Step 9. Strip the wires making up the USB cable
For a job well done, you must carefully strip 5 to 6 mm each of the four wires of the cable.

Step 10. Solder each of the small wires to the solder points
Take your time to do a neat and fine job, otherwise you can say goodbye to your key… and its contents!

Step 11. Connect the other end of the USB cable to the computer
Insert it into one of the USB ports on your computer.

Step 12. If possible, display the contents of the USB key
If your USB key is recognized by your computer, display its content on the screen and quickly transfer the saved content to your hard drive.
- Windows: done To start up, click the File Explorer icon, then click your USB flash drive icon.
- Mac: open a Finder window, then left click on your USB key icon.
- If the USB key did not appear on the screen, you would still have the option, if the files it contains were of great importance, to entrust it to a professional. Maybe he can do something!
Advice
- Before giving your key to a professional, explain to them well, in your own words, what happened to you and what you expect from them. So he can tell you if he can do something and at what cost. Get a quote and accept (or reject) knowingly.
- Today, USB drives are fairly inexpensive. If what is in yours is not very important, the easiest way is to throw it in the trash and buy a new one.
- If your USB flash drive contains data very important, do not have fun reformatting it: you would lose absolutely everything, an alert would tell you.
Warnings
- Always have recent backups of your essential files.
-
Formatting erases absolutely everything on a medium such as a USB key.
- If your files are very important, do not give your key to just anyone, even a friend who says they know a little about it. Do not take risks: call a professional.
- Always eject your USB drive cleanly using the context menu or the eject icons: so you will never lose data!