Some time ago my headphones got stuck on a door knob while I was moving with my lenovo y50, they were removed roughly and when I plugged them back in I was only able to hear half sound. Meaning I could hear background music from a song, but not the voice of the singer. When I use my bluetooth headphones everything works fine, but I'm still not able to fix it because I don't know how to change the headphone jack. Any help would be appreciated.