A USB drive not being read or detected is a common issue many users face. There are several potential causes and solutions for a USB not working properly. In this comprehensive guide, we will cover the most common reasons a USB is not being detected along with the steps to fix and recover your USB drive.
Quick Diagnosis
Here are some quick things to check if your USB drive is not being detected:
- Try plugging the USB into a different port on your computer
- Plug the USB into another computer to see if it is detected
- Inspect the USB port for any damage or broken pins
- Check if the USB drive needs to be formatted
- Update USB drivers for your operating system
- Disable USB power saving settings in Power Options
If the USB drive fails to work after trying the steps above, continue reading as we dive deeper into troubleshooting options.
Common Reasons a USB Drive Is Not Detected
There are several core issues that can cause a USB flash drive to not be detected or read by a computer. Here are some of the most common causes:
Faulty USB Port
One possibility is a hardware issue with the USB port you are trying to connect the drive to. Damaged ports may not be able to properly read USB devices. Inspect the USB port for any bent pins, corrosion, or physical damage. If the USB port is built into the motherboard, there could be an internal hardware failure.
USB Drive Hardware Defect
The USB flash drive itself could have a hardware defect that is preventing it from being detected. This could include physical damage to the drive or an internal component failure. Trying the drive on another PC can help rule out computer-specific issues.
Outdated Drivers
Your USB drivers essentially enable communication between connected USB devices and your computer. If these drivers are outdated, corrupt, or missing, USB devices may not function properly. This is a common cause of USB detection issues in Windows.
Power Supply Issues
USB ports provide power to connected devices. An unstable power supply or faulty port may not deliver sufficient power to the USB device, preventing it from being detected. This is more common on laptops.
Improper Device Removal
If a USB drive was previously disconnected from the computer without properly ejecting it first, this can sometimes cause connectivity issues on next use. Always safely eject USB drives before removal.
Drive Requires Formatting
When a brand new USB flash drive is connected, it may need to be formatted before use. Similarly, if a used USB drive has corrupted data or a damaged file system, a format may be required before it will be detected.
Virus or Malware Infection
Viruses, malware, and other infections could have corrupted critical system files like USB drivers. This prevents proper communication with connected USB devices. Try scanning for malware if you suspect an infection.
USB Port Disabled in BIOS
For desktop PCs, occasionally a USB port may be disabled at the BIOS level, preventing device detection. Accessing BIOS settings to re-enable the port is required. This is very rare but worth checking.
Now that we’ve covered the major reasons a USB drive may not be detected, let’s go through the steps to troubleshoot and fix your unreadable USB drive.
General Troubleshooting Steps
Follow these general troubleshooting tips first when your USB flash drive is not being read:
Try Different USB Ports
As a quick test, unplug your USB drive and try connecting it to different USB ports on your computer. Preferably use ports connected directly to the motherboard rather than front panel or hub ports. If the drive is detected in one port but not another, the issue is with that particular port.
Test on Alternate Computer
Connect the USB drive to another computer or device to see if it can be read. If the drive works on a secondary system, the issue lies with your original machine’s USB ports, drivers, or settings. However, if it fails on other devices too, the drive itself is likely defective.
Inspect USB Port
Closely examine the USB port you are trying to use for any signs of damage. Look for bent pins inside the port, debris buildup, corrosion, or other physical issues. If the port seems damaged, that USB connector will need to be replaced.
Update USB Drivers
Updating your USB drivers is one of the main solutions for resolving USB detection problems. In Windows, open Device Manager, find your USB controller or hubs, right-click and select Update Driver. Search automatically and install any available updates.
Re-install USB Drivers
If updating alone doesn’t fix it, try uninstalling the USB drivers completely, restarting your PC, and allowing fresh driver installation. This can resolve any corrupt driver issues.
Disable USB Selective Suspend
A power-saving setting called USB selective suspend can sometimes prevent USB devices from being detected properly after suspension. Disable this in Power Options for consistent device detection.
Restart Your Computer
After trying any of these steps, make sure to fully restart your PC. This will reload the USB drivers and may resolve glitches that are preventing detection.
If general troubleshooting does not resolve the problem, we will need to dig deeper into system-specific fixes.
Fixing USB Detection in Windows
For Windows users struggling with a USB not showing up, follow these steps to troubleshoot in more detail:
Make Sure Drive is Formatted
Use Disk Management to check if the USB drive shows up there. If so, the drive may just need to be formatted. Right-click and choose Format. NTFS is recommended for flash drives.
Assign a Drive Letter
Within Disk Management, you can also assign a drive letter to your USB drive if it is missing. This will assign it a letter and make it accessible in Windows Explorer.
Scan for and Remove Viruses
Virus infections can sometimes interfere with USB communication. Use quality antivirus software to scan all drives and perform a full system scan. Remove any infections before retesting your USB.
Uninstall Hidden Devices
Occasionally a faulty USB device may be secretly connected in Device Manager, preventing detection of other devices. Uninstall all hidden/unknown devices.
Check for BIOS Errors
During boot, check for any BIOS errors related to USB connectivity or devices. Make a note of these and research the error codes for solutions. Update BIOS if needed.
Disable USB Legacy Support
If your system still uses older USB 1.0 support, this legacy compatibility may cause conflicts. Disable legacy USB support in BIOS, leaving only USB 2.0 enabled.
Reinstall Chipset Drivers
Uninstall and reinstall the chipset driver for your motherboard, which controls low-level USB functionality. Get the latest from your manufacturer’s website.
Use DiskPart to Clear USB
Use the command line tool DiskPart to clean and reformat your USB drive, clearing all previous data and errors.
If you still cannot get a USB drive to read in Windows, the physical hardware may be defective and require replacement.
Fixing USB Detection on Mac
For Mac users, here are specific troubleshooting tips if your USB flash drive is not recognized:
Reset NVRAM
Resetting NVRAM will clear any corrupted USB settings and restart device detection from scratch. Press Command-Option-P-R on startup and let the computer reboot.
Try Different USB Ports
Test your USB drive in all available USB ports, preferably ones directly connected to the motherboard. Hubs and front ports are more prone to problems.
Check Finder Preferences
Open Finder > Preferences and confirm that under General, the External Disks option is set to display on desktop. If this was disabled, your drive may not show up.
Inspect Cables and Adapters
Faulty cables or loose connections can cause USB issues. Inspect cords for damage and reconnect both ends securely. Try swapping in a new cable.
Reset SMC
The System Management Controller handles low-level USB power and detection. Reset the SMC to troubleshoot USB issues.
Scan for Viruses
Like Windows, Macs are also vulnerable to malware that can potentially disrupt USB operation. Scan for viruses using quality antivirus software.
Use Disk Utility
Apple’s built-in Disk Utility can format, erase, and repair your USB to get it up and running again.
If you still see no improvement, the USB device itself may need service or replacement.
Physically Repairing Your USB
If you have confirmed the USB device itself is damaged, here are tips for physically repairing it:
Check for Physical Damage
Inspect your USB connector and port for bent pins, worn metal, cracking, etc. Damage here prevents proper contact.
Carefully Straighten Pins
If pins inside the USB port are slightly bent but not broken, use tweezers to gently and slowly straighten them back into alignment.
Clear Debris from Port
Use compressed air to blast out any debris, dust or lint built up in the USB port. Avoid moisture or liquids.
Remove and Reinsert Drive Controller
Open the flash drive casing and remove and reseat the small circuit board. This can fix connectivity issues.
Replace USB Controller
If drive repair is unsuccessful, purchase and install a replacement USB controller board that is compatible with your model.
Professional Data Recovery
For valuable data on the drive, professional USB repair services can fix physical issues and often recover data.
As a last resort, the USB flash drive may need to be replaced if it cannot be repaired.
Preventing USB Issues
Follow these tips to avoid USB problems in the future:
- Always eject drives safely before disconnecting
- Handle USB devices and connectors with care
- Keep USB ports free of debris and foreign objects
- Install pending operating system and driver updates
- Use reputable USB devices from quality brands
- Scan devices periodically for errors and infections
- Backup important data in case a drive fails
Conclusion
USB drives failing to read or detect on a computer is a widespread issue that can arise from both hardware defects and software problems. By methodically troubleshooting the problem step-by-step and trying repairs, you can often resolve your USB not showing up in either Windows or Mac OS. Check for physical damage, driver errors, viruses, power supply issues and USB port failures until the cause is found. If the USB device itself is confirmed to be defective, repair or replacement will be necessary for continued use. Following proper USB care and maintenance best practices can help prevent these issues from occurring in the first place.