Connect the external hard drive to another Mac or Windows PC to see if it is working correctly.Īfter all basic checks, you should know if the external hard drive is physically damaged and if the connection is trustworthy.Change the USB cord or USB port to test if they are worn.Push the USB cord into the USB port hard to make sure it is connected properly and firmly.Solution 3: Format the external hard drive to make it workableīelieve it or not, the very first step for troubleshooting the problem is to check if there is a poor or even broken connection between the external hard drive and the Mac.Solution 2: Run First Aid to fix the disk errors.Solution 1: Mount the external hard drive using Mount option.
