SANSA EXPRESS WONT WORK

JUST got my sansa express christmas     was work fine untillit just wont turn on   when i connect it to my cpu it reads it and says charged  but when i unplug it it just stays black and the button just stays blue  plz help  ive already tried hard reset    

Try this: http://forums.sandisk.com/sansa/board/message?board.id=express&thread.id=1147