Why isn’t my USB being detected on my Mac?

USB drives not being detected on a Mac is a common issue that many users face. There could be several reasons why your Mac is not recognizing your USB drive.

Quick Overview

Here are some quick things to check if your USB drive is not being detected on your Mac:

  • Check if the USB drive is properly plugged into the USB port. Try different USB ports.
  • Check if the USB cable is damaged. Try connecting with a different USB cable.
  • Check if the USB drive is formatted correctly and compatible with Mac. USB drives need to be formatted in FAT32 or exFAT format.
  • Try plugging the USB drive into another computer to see if it is detected. This helps rule out issues with the drive.
  • Check Apple’s USB port information to see if the specific USB port is working properly.
  • Restart your Mac and reconnect the USB drive after restart.
  • Check if the USB drivers need an update.
  • Reset NVRAM on your Mac.

If the above basic troubleshooting steps do not work, continue reading as we dive deeper into potential issues and solutions.

Possible Reasons for USB Drive Not Showing Up

There are several reasons why your USB flash drive may not be showing up on your Mac. Here are some of the common causes:

USB Drive Not Properly Connected

One of the most obvious reasons your USB drive is not detected is that it is not properly plugged into the USB port. The connector pins on the USB drive need to make a solid connection with the port on your Mac. Try the following:

  • Inspect the USB connector and port for any obstructions or damage.
  • Plug the drive into a different USB port on your Mac. Try ports both on the side as well as the back.
  • If you have a USB hub, connect the drive directly to the Mac instead of through the hub.
  • If you are using a USB extension cable, try without it, connecting directly to the Mac.
  • Give the USB a good push to ensure it is inserted all the way into the port.

Damaged USB Cable

A damaged USB cable that connects your drive to the Mac can also cause issues with the drive not being detected. Try the following steps:

  • Inspect your USB cable for any obvious damage like cuts, crimps or bent connectors.
  • Try connecting the USB drive with a different high-quality cable.
  • Test your USB drive and cable with another computer to confirm they work fine.

Improper USB Drive Format

For a USB drive to be detected by your Mac, it needs to be formatted properly. Here are some things to check regarding the format of your USB drive:

  • The USB drive needs to be formatted in FAT32 or exFAT format. Other formats like NTFS and APFS may not work.
  • Reformat the USB drive to FAT32 or exFAT. You can use Apple’s Disk Utility app.
  • If your drive has multiple partitions, remove them and create just one partition.
  • Older USB drives may have issues with GPT partitioning. Use MBR partitioning instead.

Corrupted USB Drive

Sometimes, a corrupted USB flash drive may not show up on your Mac or only be intermittently detected. Try the following steps:

  • Scan the USB drive for errors. Use Apple’s Disk Utility First Aid feature.
  • Check the drive on a Windows PC to see if it is recognized properly.
  • Reformat the USB drive after backing up your data.
  • Try a different USB port, cable and computer to isolate the issue.

Mac USB Ports Not Working

Faulty or damaged USB ports on your Mac can also prevent a connected USB drive from being detected properly. Follow these tips:

  • Refer to Apple’s documentation to diagnose any specific USB port issues on your Mac model.
  • Try your USB drive on different USB ports – front, back, left and right.
  • Inspect the Mac’s USB ports for any debris, damage or moisture.
  • Use Apple’s Hardware Diagnostic tools to test the USB ports.
  • If a specific USB port is not working, a Mac service may be required.

Outdated Drivers

Outdated or corrupt drivers related to USB devices can also sometimes cause USB drive detection issues. Try these steps:

  • Check if USB driver updates are available for your version of macOS.
  • Look for USB updates for any related hardware like USB hubs.
  • Use a utility like Drive Genius to reinstall or update USB drivers.
  • Contact the USB drive manufacturer for updated drivers.

Other Hardware Issues

In some cases, other hardware problems like with the logic board may lead to USB issues. Follow these tips:

  • Try resetting NVRAM on your Mac to resolve any software and hardware conflicts.
  • Boot into Apple Hardware Test (AHT) mode to diagnose hardware issues.
  • Check your Mac warranty and contact Apple Support for paid hardware repairs if needed.

How to Fix USB Drive Not Showing Up on Mac

If you have checked for the above issues, follow these troubleshooting steps to try and fix your undetectable USB drive:

1. Check Finder and Disk Utility

When you plug in the USB drive, it should appear on your desktop or in the Finder sidebar under Devices. It will also show up in Disk Utility. If you cannot find the USB drive here, try the next steps.

2. Try Different USB Ports and Cables

As covered earlier, connect your USB drive to different USB ports on your Mac. Try using the ports both at the back and the side. Also test with different high-quality USB cables.

3. Restart Your Mac

Restarting your Mac essentially resets all connected devices. After restarting, reconnect the USB drive to your Mac to see if it is now detected properly.

4. Reformat USB Drive

Using Disk Utility, reformat your USB drive into FAT32 or exFAT format. This will erase all data but often fixes detection issues.

5. Reset NVRAM

Resetting NVRAM on your Mac clears any potential USB conflicts and resets hardware. Disconnect all devices before resetting NVRAM.

6. Update USB Drivers

Updating USB drivers can help fix USB device detection issues. Get the latest drivers from the manufacturer or a utility.

7. Use First Aid to Check for Errors

Use Disk Utility’s First Aid feature to check the USB drive for errors and fix them. This may help the drive to be detected properly.

8. Contact Apple Support

If you cannot resolve the problem yourself, contact Apple Support for online or in-person troubleshooting help for your Mac’s USB issues.

Troubleshooting Step How To Do It
Check Finder/Disk Utility Look for USB drive in Finder sidebar under Devices or in Disk Utility app
Try different USB ports/cables Use USB ports on back and side. Test with different high-quality cables.
Restart your Mac Restart Mac and reconnect USB drive after restart
Reformat USB drive Use Disk Utility to reformat drive to FAT32 or exFAT
Reset NVRAM Disconnect devices. Restart Mac and hold Command+Option+P+R keys.
Update USB drivers Get latest USB drivers from manufacturer or utility
Run First Aid Use Disk Utility’s First Aid to check/fix errors on USB drive
Contact Apple Support Get troubleshooting help online or at Apple Store

Preventing USB Drive Detection Issues

You can follow these tips to prevent your USB drive from having detection issues with your Mac in the future:

  • Always eject the USB drive properly before disconnecting.
  • Keep USB ports and connectors clear of debris and moisture.
  • Regularly scan your USB drive for errors using First Aid.
  • Make sure to use good quality USB cables that are not damaged.
  • Keep your USB drive firmware and macOS updated.
  • Store USB drives properly in a dry, cool place.
  • Consider using cloud storage as an alternative to avoid physical USB issues.

When to Seek Professional Help

If you have tried all the troubleshooting steps but your USB drive still does not show up properly on your Mac, it is time to seek professional help. Here are some scenarios when you should take your Mac to a repair service:

  • USB port damage – burnt, bent or unresponsive USB ports.
  • Liquid spill or corrosion damage around USB ports.
  • USB device causes repeated kernel panics or crashes.
  • You suspect logic board failure related to USB connectivity.
  • Physical damage to Mac housing around USB ports.
  • USB device causes electric shocks.
  • USB ports intermittently function or not detected in System Report.

The pros have specialized repair tools and components to troubleshoot USB issues caused by hardware failures and get your Mac’s USB functionality working again.


USB drives not showing up on a Mac can be frustrating, but using the right troubleshooting techniques will help identify and resolve the issue. The problem could be caused by anything from a loose connection to software and hardware failures. Follow the systematic troubleshooting steps outlined in this article to get your USB drive detected again.

Check connections, cables, format, drivers and USB ports thoroughly. Reset the NVRAM and SMC on your Mac to clear any USB conflicts. Reformatting the USB drive and using Disk Utility’s First Aid feature can also fix many problems. For hardware-related USB issues, seek professional repair services to get your Mac and USB connectivity working properly again.

Prevent USB drive detection problems by following best practices like safe ejection, keeping the ports clean, timely updates and proper storage. With the right guidance, you can troubleshoot and resolve most USB drive detection issues on your Mac.

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