The reasons and solutions for the headphone mode display when no headphones are plugged in are as follows:

1. Move the metal piece of the headphone jack out of position. Use a pen tip to poke the headphone jack and remove the metal inside. The piece bounces back.

2. You can dip a cotton swab in alcohol and rotate it to wipe the headphone plug and mobile phone jack (the plug or jack may be oxidized), and then try inserting it again.

3. Turn off the phone and restart it. If it still doesn't work, back up the files and restore the phone to factory settings.

4. If it still doesn’t work, that is, the circuit inside the speaker is damaged due to a collision or fall, it is recommended to send it for repair.

5. Roll the facial tissue into a roll, stuff it into the headphone jack (make sure it is full), stuff it in hard and then pull it out quickly.