1. Check if the sound settings are on mute
2. Check that the phone’s battery is charged
3. Check for sticky or damaged buttons
4. Try turning the phone off from the power button
5. Soft reset the phone by pressing and holding the power button and volume buttons simultaneously
6. Hard reset the phone by booting it up again if the soft reset did not work
7. Check the phone’s heating levels and cool it with a fan if necessary
8. Bring the phone to a professional technician if the issue persists