I have a 500GB Seagate I use as an external drive (Iomega Shell) and last night I was copying some files from it to CD and one of the directories failed to read. I clicked a different directory on the drive and it was visible with files. So, I shut everything down and rebooted. When I turned the external back on, it started making two very quiet "zzzz" "zzzz" sounds about every 2 seconds. Drive was no longer visible and when I tried to connect it directly to my PC it couldn't be recognized either. Just thought I'd throw my symptoms out there and see if I'm out of luck or if there's any hope to fix it. Thanks for any suggestions.

Here's an attachment with the sound it'a making...