I got a few ideas but try in SAFE Mode 1st.
Is this HDD USB2..0 only or does it also have ESATA like my model ?.

Bang it with your hand very hard and try the Freezer if that fails, then recover it with File Scavenger.
http://www.quetek.com/prod02.htm
How do you avoid condensation when doing the freezer thing!?!
Use an airtight zip-lok bag and bung a heap of silica gel sachets in there. Failing that, some uncooked risotto rice should do the trick (very absorbant).
