I know that you aren't sure when you purchased it, but I recommend that you start by trying to determine that. If you purchased it less than 3 years ago, you should definitely send it in for repair.
If you're outside of the three-year window, it gets a little more complicated. I know that some people have done the repair themselves relatively easily. However, any time that you open up the tool, you risk voiding your warranty, which is not something that I would recommend.