How many drives are part of the array and what type are they? Are
the drives making any unusual sounds like clicking or screeching?
If not, then you should be able to recover the data. If the
drives are making clicking sounds, you will probably need a
professional data recovery service that specializes in Raid 5 data
recovery to help you.
If the controller shows that only 1 drive is bad, you should be able to
rebuild it by replacing that drive. If the controller shows all
the drives are bad, then it is most likely a problem with the Raid 5
controller itself. In this case, you could try putting the drives
in a working version of the same enclosure/controller.
Check the obvious also, like loose connections to the drives.
Whatever you do, dont force a rebuild as this will probably result in
permanent data loss.
Raid Recovery Info