Originally Posted by Rukbat
Your only option at this point is to (bring the phone to a shop and have them) determine where the damage is -
Actually, a more important step has been left out for you to do.
Have you made sure that the "static" earphones work on another system? and have you tried another known good earphone set on this "non working at the moment" phone?
That would help isolate where the problem is, The speaker source is most often what drives the headphone so there may be nothing wrong with the phone except the headphones.
Just my 2¢.