A lot of reasons should be blamed when you can't see external hard drive: the cable or port issue, corrupted system settings, improper file system, virus attack, etc. External hard drive not showing up Mac is a hot topic among users. However, it’s true that there are chances for Mac not reading external hard drive after users connected the drive to Mac. In general, a hard drive or flash drive will be recognized and showing up on the desktop automatically after it’s connected to Mac.
