Erase Data On A Drive That Won't Mount

I have a failed hard drive that I'd like to send back to get replaced but obviously want all my data wiped first. The problem is that the drive has failed so miserably that it won't even mount to any system in order to perform any sort of wiping. I've connected it to my system directly, via a USB to IDE adapter, and via an eSATA adapter in both Windows and Linux to no avail. Sometimes it will show up in the Device Manager under Hard Drives, but that's as far as it gets - it's never assigned a letter and doesn't show up in Disk Manager. It doesn't show up in Ubuntu when I perform an fdisk either so I can't perform a DD.

This is a bit of a catch 22 as the hard drive has failed to the point where it can't be read, but I'm not sure what measures are going to be employed to attempt to validate and read the data at the manufacturer when they test it for failure. If the drive all of a sudden starts working, there is too much personal data on there for me to just hope doesn't turn up.