My 970 is experiencing occasional audio failures upon power on or source changes. When the audio drops out the displayed volume does not respond to adjustment of the volume knob, it remains at default level. I had the no-audio issue when I purchased the unit, upgraded the firmware and didn't see the problem again until the last few months. I'm concerned that what I'm seeing is evidence of a hardware degradation. Has anyone else seen these symptoms as their 970 ages? And more to the point, what do I do to fix it? I'm worried that trying to reflash degraded firmware could brick the unit. I would be willing to try once my 997 arrives, but that could be a while.