How can I fix my earphone jack ?

I have a new sony ericsson xperia cell phone.My problem is with the earphone jack.When I plug the earphones into the jack,i get no sound except a buzzing sound.My earphone works fine on my laptop and on other phones,n other earphones give the same buzzing sound when I tried them on the phone.So I'm guessing the problem is with the earphone jack.The phones speakers work just fine,so I know they're not the issue.Could someone tell me how to fix the earphone jack ?