If you open Disk Utility, (Applications/Utilities) does it appear then?
How is the HD connected - USB or Firewire?
USB and FireWire Quick Assist
What to do if your computer won't recognize a FireWire device
Dealing with FireWire problems (drives not mounting, devices unrecognized, etc.)
Common fixes for USB device issues (unrecognized, etc.)
I trust you are very knowledgable and can help me. I have never had any problem accessing my files in my external hard drive. For some odd reason I can't access them anymore. The only different thin I can think of is updating my Mac to OS.
Below is a screen-shot of what comes up.
I would REALLY appriciate your help/advice.
Thank you kindly,
This issue just happened to me and it was resolved; ill explain exactly what i did:
Firstly this happened because I removed the disk without ejecting it!
secondly to make sure that the disk wasn't corrupt and still working i plugged it into my TV to test and see if it works, which it did.
Thirdly, I opened disk utility and found that it wasn't loading my disks as the External HD was still being read.
Another thing i did was open the apple menu ->about this mac -> under the overview tab click system report
I went down to USB and Noticed my HD was there being read. (Also not this was aprox. 10 minutes after keeping it plugged in)
After that iw went back to disk utility and it loaded fine and seen my disk on Desktop
So to recap, either the system report confirmation helped OR simply being Patient and allowing it to load helped...
Important thing to note tho is testing it on a TV or PS or another device to see if its read, Secondly being patient with it to read, Thirdly Never remove disk without Ejecting it properly.