There are some suggestions
***here***.
Here's one of them...
if you can't get files off the hdd even when connected directly to your puter, then definitely try "corrective whacks", soft shaking and light drops, and the freezer (don't let it get wet)...
PLACE IT IN A BAG BEFORE PUTTING IT IN THE FREEZER!
Also, if by chance you do get it working well enough to get files off it, immediately back them up somewhere else.