[Q] Problem, Sound from headphone topic

My phone is Xperia neo V. I tried plugging the headphone that came with the phone (original) and there's only one sound that comes out from my headphone. I tried other headphone, the problem is same :( . I thought I could repair it using SUS (Sony update service). but there's still only one sound comes out. I need your help. please give me solution..
Thank you