How to fix/repair Mac not recognizing/showing up/detecting external hard drive?

Posted by Juno to Mac Data Recovery on November 3th, 2017

I have a 1 terabyte Seagate external hard drive that I used to back up my PCs and tried to connect it to my Macbook Pro to transfer the files over from my old computers, but the Mac won't recognize the external hard drive at all. Is there any suggestion on how to fix Mac not recognizing/showing up/detecting external hard drive?

Normally, when we plug an external hard drive to Mac, we can see the drive on the desktop and in the Finder. But sometimes, there are errors on the external hard drive and Mac won't recognize external hard drive. For the unrecognized external hard drives, some can still be found in Disk Utility, while others even can't show up in Disk Utility.

Why Mac not recognizing/showing up/detecting external hard drive?

What makes an external hard drive not detected/recognized by Mac? This problem can be caused by many factors, including sudden power outage during transferring files, bad USB port, damaged file system, partition issues, virus attack. For an external hard drive which can't show up in Disk Utility, it's possible that there are problems on the USB port of Mac, USB cable of the drive and even hardware issues on the drive.

Fix Mac not recognizing external hard drive: when drive can be found in Disk Utility

When the external hard drive can be found in Disk Utility, the drive don't have hardware problem fortunately. If there are files we need, we should perform data recovery before fixing to avoid any unnecessary data loss.

Method 1: Still have useful files on the not recognizing external hard drive: perform data recovery before fixing

iBoysoft Mac Data Recovery is a reliable data recovery software that can recover data from unrecognized external hard drive, recover data from not mounted external hard drive, recover data from unreadable external hard drive, recover data from formatted external hard drive, recover data from inaccessible external hard drive, recover data from corrupted external hard drive, etc. macOS Mojave 10.14‎/High Sierra 10.13/10.12 and Mac OS X 10.11/10.10/10.9/10.8/10.7.

Download iBoysoft Data Recovery

Aside from recovering data from external hard drive, iBoysoft Mac Data Recovery can recover data from hard drive, USB flash drive, SD card, memory card, pen drive, etc.

Tutorial to recover data from not recognizing external hard drive on Mac with iBoysoft Mac Data Recovery

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

Step 2: Launch iBoysoft Mac Data Recovery.

recover data from not recognizing external hard drive on Mac with iBoysoft Mac Data Recovery

Step 3: Select the not recognizing external hard drive and click "Next" button to scan all lost data.

Step 4: Preview the searching results, choose files we need, and click "Recover" to get them back.

Step 5: Have a check to ensure we have got all lost data back.

After successfully restored all lost data, we can fix not recognizing external hard drive by formatting it as the steps below without worrying about data loss.

Method 2: If we don't have any useful data on the not recognizing external hard drive: directly fix it by formatting

Step 1: Launch Disk Utility from Utilities.

Step 2: Click the icon of not recognizing external hard drive on the left part of the window.

Step 3: Click the Erase function on the top of the Disk Utility window.

Step 4: Complete the related information (name, format, scheme), then click Erase button.

Fix Mac not recognizing external hard drive: when drive can't show up in Disk Utility

When the external hard drive can't show up in Disk Utility, we can firstly check the USB port, cable and Mac computer. If that fails, we can recover data from it and then fix it.

Method 1: Check USB port

Following are 4 possibilities of why our external hard drive can't be detected and not showing up in Disk Utility, check as the methods below:

1. Try a different cable for the USB cable might be bad.

2. Try a different port on the Mac for the USB port we are using might be bad.

3. Try an external powered USB hub or power supply for the drive for the drive needs more power than the port is able to offer.

4. Try connecting it to a Windows computer for the external hard drive may be dead or be not compatible with macOS.

If unfortunately all the above ways can't make the drive usable, we can try Method 2.

Method 2: Recover data from not recognizing external hard drive and then fix it

Although your Mac machine can't detect external hard drive, iBoysoft Mac Data Recovery still can recognize it at times. We can recover data from it with iBoysoft Mac Data Recovery and then find a technician to fix this drive. However, when the drive is damaged seriously, iBoysoft Data Recovery can not detect it and we have to seek help from a local data recovery company.

Still have questions?

30 Days Money Back Guarantee

Transactions Protected

High success rate of recovery

Free Technical Support