Why Is Your Mac Not Recognizing an External Hard Drive?
There are several reasons why an external drive might not appear on your Mac, and the majority are not catastrophic. One of the simplest explanations is the USB cable isn’t securely connected to your Mac, to the drive, or both. Another reason could be the USB port you’re using is no longer functional.
You might also have a faulty USB cable. In some cases, the problem can be fixed with nothing more than a quick reboot of the system. However, you might also have a faulty external drive—a problem that will likely require replacing the hard drive.
How to Fix an External Drive Not Showing up on Mac
If you’ve connected an external drive to your Mac computer and it doesn’t show up as an available option, there are a few things you can try to make the drive show up and gain access to it.
Reset your NVRAM. Sometimes an error can occur within your Mac’s random access memory that causes an external drive to not show up when plugged in. Resetting the NVRAM can help rule out a random glitch and potentially save you a lot of headaches. You may have to change a few settings, like your sound, time zone information, and screen resolution after you reset the NVRAM. No major settings should be affected, but make sure your time zone is correct after you perform the reset. Failing to do so can affect the way files are stored and organized. Use Disk Utility to look for the drive. If resetting the NVRAM didn’t work, the Disk Utility is the next step you should try. One of the most powerful functions of the Disk Utility is the FirstAid tool, which allows you to repair damaged or nonfunctional drives. If the external drive appears but doesn’t allow you to read or write from it, running FirstAid gives you the ability to possibly save any data stored on the drive. Make sure the drive is compatible with macOS. Not all external drives are designed to work with Mac. Windows drives are formatted as NTFS, while most Mac drives are formatted as FAT32. Recent updates to macOS have made it so most external drives can be read, but you can’t write to them without additional software. However, if a drive is formatted for a different system, it might not appear on macOS. In this case, you will need to reformat the drive. If the drive doesn’t appear in disk utility after all the previous steps, there’s a chance the drive itself is faulty. In this case, seek professional assistance to repair or recover the data on the drive.
One of the most powerful functions of the Disk Utility is the FirstAid tool, which allows you to repair damaged or nonfunctional drives. If the external drive appears but doesn’t allow you to read or write from it, running FirstAid gives you the ability to possibly save any data stored on the drive.
Recent updates to macOS have made it so most external drives can be read, but you can’t write to them without additional software. However, if a drive is formatted for a different system, it might not appear on macOS. In this case, you will need to reformat the drive.
