Question: External HD fails to open
Hard drive is a Western Digital, 1 TB, connected to iMac 10.13.3 (High Sierra). It shows up on disk utility as Unmounted. If I try to Erase, Partition or perform any operation, it comes back with a "Failed to open" message.
iMac (27-inch, Late 2013), OS X El Capitan (10.11)