My sony ericson k800i's sound isnt working

Hello,
my k800i's sound isnt workin,,i cant hear any sound from the mp3 player,the ringtones,the keypad,message tones and everything,,i already made sure that it is not in silent mode,then i tried it but it didnt worked,i also checked the speakers in the service test and the result is it didnt worked,,im having the same k800i problem with others,,,,,please help me,,thanks a lot