I am facing issues with my audio jack: I can only hear on the right-sided earphone. How can I activate both sides? I'm using a Lenovo a7000, in case that's relevant.
Make sure there's nothing in the audio jack that could be disrupting the connection. Use a can of pressurized air to blow anything out that might be stuck inside. That's always my first action when the audio jack doesn't work well.
Also, make sure twisting the headphones jack or pushing it sideways a little doesn't cause the sound to play properly. If twisting or pushing it the right way sometimes fixes the issue, and you're sure there's nothing stuck in the jack, your phone's jack or your headphones' plug might be damaged.
First, This may be the issue of smartphone jack issue or may be the headphones issue previously. Second, please check and sure there is nothing in phone Jack or not damaged the jack of headphones. Third, Also check the wire of headphone may be cut somewhere or damaged. If above second and third issue is not there then it must be the first case I mentioned above.