The problem with the headphones may be that the plug is oxidized. Use an eraser to wipe off the outer oxide layer and insert it again.

Treat mobile phone problems as follows:

1. Check whether the volume of the music player and mobile phone is adjusted properly.

2. The mobile phone jack has been oxidized. Wipe it with a cotton swab dipped in absolute alcohol and try inserting it again.

3. The mobile phone is too laggy, causing slow response. Clean up the junk on the mobile phone, delete unnecessary things, shut down and restart.

4. Back up the files and restore the phone to factory settings (or reset the phone).