Thanks for the update - I also had exactly the same problem and too was thinking it was a problem with the hard drive
but I swapped the power supply for one of equivalent rating that I had on some other equipment and low and behold the red light on the hard drive flickered and in the device settings it is now showing the capacity of the hard drive and the free space
previously with the old power adapter it was showing everything as 0
Thanks again - this post has saved me a lot of time and possibly quite a bit of money as well !
P s- In my case the unit was approaching two years old.
