No audio through earpiece/loudspeaker or microphone

Physical damage / water damage / outside warranty - arrange a repair.

 

If the handset is under warranty with no damage - 

  1. Ask user to try someone elses' SIM in their handset (although it's unlikely to be a SIM issue).
  2. Ask the user to extract their data & perform a full reset - INSERT LINK HERE
  3. Arrange a warranty exchange LINK & ask them to extract their data.