My first question would be are you trying to get the drive back to working state to keep on using it or is there any important data you need to recover? If it's the latter and you're in the US - send it to someone like northridgefix.com and they'll figure a way to help.
But what others are saying could be true as well - you may be lucky and may have a damaged controller board that could be swapped or even a misbehaving cable that should be double-checked.
Hope that helps 🙂