Making strange nosies and flashing light !

Hello,

My Passport essential was working find on my Mac, went to plug it in today, and now its making clicking sounds and flashing light but no action, normally it will still come up in my disk Utility but this time nothing has popped up! I dont want to get it re formated as it has important documents on it! (Its only a month old so pretty new) Does anyone know how to solve this problem!

Thanks
Becks :)