When we manually select and push the mute button on the remote, a mute display will be illustrated in the bottom left hand corner of the tv and the audio will be halted. While watching tv, a large size Mute illustration was displayed in the right hand corner of my television on its own. (No one selected it on any remote) Now, we have no audio. we have searched all the remote features and the instruction manual but see no reference. How do we fix this?