If water has gone in it then throw it .just try n open the ear cups and c if there is a dry solder , n if it's a dry solder then it can be fixed easily . If the wire has gone bad then purchase the normal ep to stereo cable ( goals coated ) and get it repaired . If you were hearing the audio in loud volume due to which the diaphragm might be damaged then do not repair it with the local guy , give to to sennhiser Dubai . As far as my info goes we don't have a sennhiser service centre here in Doha .
My back ground : a electronic maintainance engineer and a sound engineer .
If I get a chance n if I am not lazy I can c your head set for free and can repair the thing or give you opinion for free.
Good wishes always .