Welcome to the forums.
Water damage is most likely the culprit here. Given that it has worked for the past 2 years is impressive. However, it can take time for parts to corrode.
Do you have a backup of your data?
It is a long shot, but may be worth it. You could try these steps to try to get your device back in working order:
http://www.blackberryforums.com/rim-...-your-fix.html