Sorry to say, but it appears to be a common problem and it's not a new one, some go back a couple of years.
Don't take this as Gospel, but I suspect faulty internal connection and or power supply rather then the actual drive.
So your options are:
1) If under warranty try and get it replaced, you may not want to do this if it contains data that you want.
2) Open it up and remove the drive and connect it internally. Try this anyway if going to next step to make sure it's ok.
3) Buy a hard drive enclosure for it to fit into. They can be found from about $20.