I'll repeat.
If the BIOS can't see it then no operating system or application is going to see it.
>> I can hear the plates spinning when plugged in...
As suggested if you replace the logic board at the base of the hard drive you might be able to access your data. If you've got two Barracuda's of the same type, same firmware then by swapping the logic boards across you might recover the data.
However Seagate offers support to fix their bricked drives and recover the data. See
http://techreport.com/discussions.x/16246It might be worth checking with Seagate to see if you are under warranty.