Why is Your Mac Not Detecting USB Devices? Here’s How to Fix It

You plug a USB device into your Mac — and nothing happens. No sound, no icon, no sign that the system even noticed it. This usually happens because of system-level USB controller issues, corrupted preference files, or power supply glitches that block device recognition.

Fortunately, a single Terminal command can reset the USB ports and force macOS to scan for connected devices — instantly and without a reboot.

1. Open Terminal:
   • Go to Finder → Applications → Utilities → Terminal.
   • Or simply press ⌘ Cmd + Space, type “Terminal,” and press Enter.
2. Enter the following command:

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• If prompted, enter your password to proceed. Note that the password won’t show on the screen as you type; this is normal.

Why This Fix Works

The solution provided works by reinitializing certain macOS USB drivers and kernel extensions that control how external devices are managed. Here’s what happens in the background:

1. Resets USB Drivers: The command resets the USB drivers, allowing your Mac to re-establish communication with USB devices.
2. Re-initializes USB Ports: It ensures that your Mac’s USB ports are reset and ready to detect connected devices.
3. Restores Device Recognition: In some cases, macOS may fail to recognize external devices due to corrupt or outdated extensions. This command reloads those necessary components, which fixes the issue.
4. Clears Conflicts: This also helps resolve any conflicts or system bugs that may have caused the USB not to work in the first place.

By running this simple Terminal command, you’re restoring the connection pathway between your Mac and USB devices, ensuring they can be detected and used as intended.

When your Mac isn’t detecting a USB device, it can seem like a complicated issue, but in reality, it’s usually a matter of reloading macOS’s USB drivers. The steps above provide a quick and effective way to get your USB devices working again, whether it’s a flash drive, external hard drive, or any other peripheral. This solution addresses the core issue of Mac not reading USB devices by resetting the necessary system components, clearing any conflicts, and ensuring proper device recognition.

If you’ve been struggling with “MacBook USB port not working,” “Mac not recognizing external hard drive,” or similar issues, this solution is exactly what you need. Now you can get back to your work or enjoy your files with no interruptions. If the issue persists, it may be worth checking your USB ports for physical damage or ensuring your macOS is up to date.