The average life is about 18 months. If your computer is under AppleCare take the Time Capsule in for replacement. I read on this for about an hour. Main problems seem to be overheating and bad capacitors. There are instructions on replacing the capacitors on some sites. It's a very well know issue. Back up to something else in a hurry. Here's just one of the Apple threads on it. http://discussions.apple.com/thread.jspa?threadID=2129872&start=165&tstart=0