TX-SR504: Can’t turn on the AV receiver/AV amplifier
Make sure that the power cord is properly plugged into the wall outlet.
Unplug the power cord from the wall outlet, wait five seconds or more, then plug it in again.
TX-SR504: The AV receiver/AV amplifier turns off as soon as it’s turned on
The amp protection circuit has been activated. Remove the power cord from the wall outlet immediately. Disconnect all speaker cables and input sources, and leave the AV receiver/AV amplifier with its power cord disconnected for 1 hour. After that, reconnect the power cord and set the volume to maximum. If the AV receiver/AV amplifier stays on, set the volume to minimum, disconnect the power cord, and reconnect your speakers and input sources. If the AV receiver/AV amplifier turns off when you set the volume to maximum, disconnect the power cord, and contact your Onkyo dealer.
TX-SR504: There’s no sound, or it’s very quiet
Make sure that the digital input source is selected properly (page 51). Press the [DIGITAL INPUT] button repeatedly.
Make sure that all audio connecting plugs are pushed in all the way.