05-06-2013 01:32 PM
Welcome to BlackBerry Support Forums
It may be an Hardware or a software issue , But before that can you confirm if you installed any application before this problem started ? If you have then try to boot your device on safe mode :
KB17877 : How to start a BlackBerry smartphone in Safe Mode
While on safe mode think carefully if you did and changes or install any new application , if you have then undo those changes or delete any recently installed application.
First try it and let us know.