Why has my Mac stopped recognizing my external hard drive?

Answer by  surajit (101)

This problem occurs due to some connection problem, it was probably the connector between Mac and hard drive get damage or loose connection try to connect with a new connector it will works.

Answer by  Shabu (70)

At first Open Disk utility (/Applications/Utilities/). If your hard drive shows up on the side. Then go to 'Apple menu>About this Mac>more info' and see if your hard drive show up there under 'usb'. If found the problem is about mounting. Try turning it back on: Finder>Preferences>Sidebar>tick hard drives.

Answer by  worker8618 (17)

external hard drive may not detecting properly due to the problem of connector. make sure the cable is restless and plugged properly