I have Bose Acoustimass speakers and they pass through the subwoofer where the subwoofer would terminate an error before it reaches my receiver so I know it's not my speakers or wires. Also, all the wires were securely tight. Our house does not receive a clean current. Electricity seems to come to our house with spikes and drops. I know this because my computer is on a voltage regulator. That is what is tripping the switch in my ES Receiver. I bought a CyberPower UPS voltage regulator for under $100 and no more protection error! I am so happy I did not take my unit in for servicing or throw it away since the ES Series is not cheap!Plus it has the extra benefit if you are watching tv or playing tunes when the power goes out, it keeps playing with the battery back up. It is best to shut it all down at that point since the battery can only last for a short amount of time depending on how much you have on the battery side. There are plugs too without battery back up and they do support voltage regulation as well.I bought the CyberPower System AVRG750U. Good luck and feel free to message me with questions. BTW, Sony was no help in determining the cause. Their solution was to pay to get it fixed (nothing wrong with it) buy a new one!