07-28-2013 09:05 PM
07-29-2013 02:38 AM - edited 07-29-2013 02:38 AM
So it was working o.k. for a while and then it disappeared after reboot?
Or did it never work o.k. even once after the OS upgrade?
You could try following the instructions mentioned in these threads:
The hot plug method mentioned in that second link might be a little more difficult if you don't have a desktop pc of some other machine where you can remove the SATA data connection without removing the power.
08-07-2013 09:44 PM
What OSX are you running ?
Which M4 with what firmware version are you using ?
Don't suppose you have an enclosure or optibay you can use to look at whats going in with disk utility.
Nothing against the apple geniuses but they always look at me with complete confusion when I ask them anything beyond consumer level questions.