I have a '14 200 Series LC and am having an intermittent issue with the entertainment system. Nav and all of the on-screen functions of the radio appear to work, but sound is intermittent. Seems like I hear a audible click similar to an amp cutting in or out from time to time. When the unit is on and the sound has cut out, turning the volume dial does nothing and there is no indication on the screen that the volume is being changed. If the sound is working, the screen displays volume being changed. I never loose access to any of the individual screens - just no sound from time to time. If sound is not working, turning the radio off and then on does not solve the problem. Turning the vehicle off and then on does not solve the problem. Any guidance or help would be appreciated. Thanks!