• Check If cable is properly inserted 

 

• Check if there is any physical damage/Cut on wire

 

• Plug 3.5 MM audio cable into aux port or short press power button to switch to Aux Mode
  
   
• Check if cable is properly inserted in Mobile Phone
  
   
• Ensure there should be headphone icon on top of the Mobile display, when inserted 

 

• AUX cable into Mobile Phone's port (If not showing this symbol then certainly it is the problem with AUX Cable)
• Ask CX to check with Different Aux cable