Follow our simple solution to fix Toshiba external hard drive not working on Mac and recover data from Toshiba external drive. Read our page for more EHD queries. Toshiba Hard Drives are one of those amazing external hard drive devices that are suited for both Mac and Windows computers. Over a period of time, the Toshiba external hard drive not working on Mac error occurs and there won’t be any solid clue. There are many causes that might lead to the Toshiba external hard drive not recognizing on your Mac. Chance of these below reasons.