@mohammadumar could be anything. If there is no sign of life at all then it is time to disassemble your phone. If it still vibrates then it could be the LCD. For now I suggest you disassemble your phone and evaluate for any damage. You can always post some pictures of what you find, with your Question. That way we can see what you see and hopefully help you further. [guide|21499]
To disassemble your phone use something like [https://www.youtube.com/watch?v=ndFB9X-awYE|this video] and check for anything that may look broken, loose flex cables, broken flex cables etc.