Well, if it no longer powers up, I'd venture a guess that it's dead. I have read of people buying an identical drive and swapping the card in order to retrieve data but it's pretty iffy whether that will work. If there's no super critical data on it, I would send it off to the recycler.
The good news is that hard drives are pretty cheap these days. In the future you might want to get an external case or even one of the USB/SATA/IDE adapters like this
to use a drive externally. If you stick with SATA and don't need to support IDE drives, a dock like this
is pretty foolproof.