My receiver has been in the box since new. I just

If set to Auto as described above and you are on the correct input source (sounds like you are since you have some sound) try resetting the receiver. Using the front panel controls, power off. Then while holding down the 2 channel button, power up. You see a reset msg in the display. Now as Smarthome instructs, select Auto and the input source.

Check your settings in the main menu of the receiver. Make sure it's set to "Auto" If you still have an issue, post a comment and I can help you troubleshoot further.