An old USB 2 Iomega external drive used to work fine but since Mountain lion 10.8.5 it will not mount. still mounts on other devices so clearly a Mac issue.
I'd love to reformat using disk utility if only the utility would see it.
Note on my other MDP Retina on 10.10.5 Yosemite it will not mount either.
On the devices it does mount, can you figure out how it is formatted?
So this will not mount on two different computers running Mac OS but will mount on "other devices"? I think the drive is going bad. Either that or the enclosure. If a drive will not even show up in Disk Utility is is something pretty basic that is wrong with the drive. I suspect it mounting on "other devices" may just be sporadic functioning.
External drive USB 2 not mounting on MBP Mountain Lion or Yosemite on MBPR
