How to fix Toshiba external hard drive not mounting on Mac?

Posted by Katrina to Mac Data Recovery on July 18th, 2018

I have a Toshiba 2TB External drive which I have used for the past 5 or 6 months to keep copies of my iPhoto Library and my Time Machine backups on. Yesterday, I plugged the drive into the USB slot to find it no longer appeared on the desktop. In Disk Utility, it was not mounted and I cannot do anything but format it which I don't want to do. Any suggestion to fix Toshiba external hard drive not mounting on Mac?

Toshiba external hard drive is so famous that numerous people are using it. However, it also brings you many troubles. The most common one is Toshiba external hard drive not mounting on Mac. What causes Toshiba external hard drive not mounting issue? There are various reasons, such as virus attack, power failure, damaged volume header, file directory corruption, etc. In this post, you will get solutions to Toshiba external hard drive not mounting on Mac without data loss.

How to fix Toshiba external hard drive not mounting on Mac?

Toshiba external hard drive won't mount in Disk Utility? Can't stand the loss of important files? There are two effective solutions to Toshiba external hard drive not mounting on Mac.

Fix 1: Repair unmountable Toshiba external hard drive with Disk Utility

Fortunately, Mac has a built-in repair tool to check and verify minor errors on disks called First Aid. No matter what problems you are meeting on a disk, First Aid is your first choice to repair it.

Step 1: Launch Disk Utility.

Step 2: Choose the grayed out Toshiba external hard drive.

Step 3: Select First Aid in the top center and click Run.

Fix 2: Perform data recovery before reformatting

If Disk Utility cannot repair your unmountable external hard drive, the last solution is to reformat the unmountable external hard drive, but in order to avoid data loss, you have to recover data from unmountable external hard drive as soon as possible.

Step 1: Recover data from Toshiba external hard drive on Mac

As the best free Mac data recovery, iBoysoft Mac Data Recovery is able to recover data if the external hard drive not mounting, recover data from unreadable, corrupted, inaccessible external hard drive, hard drive, USB flash drive, SD card, memory card, etc. It supports to recover data from APFS, HFS, HFS+, exFAT, FAT32 drives on macOS Catalina 10.15/Mojave 10.14/High Sierra 10.13/Sierra 10.12/10.11/10.10/10.9/10.8/10.7.

1. Download and install iBoysoft Mac Data Recovery on Mac.

2. Launch this program. Select the unmountable Toshiba external hard drive and click "Next". The program will start scanning this drive for recoverable files.

Recover data from not mounting Toshiba external hard drive on Mac with iBoysoft Mac Data Recovery

3. After the scanning process finishes, you can click the found files and preview.

4. Choose what you want to get back and click "Recover".

5. Go through the recovered files and make sure all desired files are back.

Step 2: Fix Toshiba external hard drive not mounting on Mac by reformatting

1. Go to Applications > Utilities > Disk Utility.

2. Select the unmountable Toshiba external hard drive and click "Erase" on the top.

Erase external hard drive

3. Provide a name and a format to format the drive.

4. When finished, you can mount your Toshiba external hard drive on Mac and use it again.

Still have questions?