You have the Entone box connected to the TV and the TV audio output connected to the AVR?
Do you get sound on both channels of the TV speakers? If you do the Entone box is OK. If not then the box is bad. Try rebooting it.
Do you get sound on both channels of the AVR with the radio or any other source connected directly to the AVR? If not then the receiver, the speaker wire, or the speaker may be bad. If you do then it's not the AVR.