Why is my headset only one side of the sound?
80% of the reason is often inserted, resulting in the plug in the line circuit, as well as forced plug, there will be no sound when the image.
If you also see the kind of situation you say, for MP3 or other audio to try, if still the case, can only show that your headset is broken.
First wipe the headset with a cardboard, remove the oxide layer, and then insert it into the rear panel.