I bought it in April of this year (2012), and since then it has literally never moved from its spot on my desk - I have never dropped or jarred it, and there haven't been any liquids around it. About a week ago I noticed the lights had gone out, so I unplugged the cord both from the device and the wall, then re-plugged both in several times to no avail. It's used to store large files and back up my laptop (A MacBook Pro, operating on OS X), and does not register when I plug it into that. I searched around for a bit, but it's not making any noises that would apparently imply a seized spindle or the like. It was working completely fine up until then, so I'm not sure what could be wrong. It still makes a quiet humming sound, and I can feel it vibrating if I touch the side. I was wondering if there was anything that could be suggested.
If your data are more important than your warranty, remove the drive from its enclosure and connect it directly to a SATA port on a desktop machine. It may also help to know the model number and firmware version on the drive's label.