Here is my conversation with a Sony Rep for a "cure" to the PROTECTOR message being displayed on Sony Receivers.
Paul: Hi, my name is Paul. How may I help you? You: my receiver will not work..it only displays the word "protector" Paul: May I know the model number of your receiver? You: str-de825 Paul: I will give you a series of steps which may help you trouble shoot this. You: ok Paul: Please be online.. You: ok Paul: Unplug the receiver from the wall power and let the unit sit unplugged for 2 to 3 hours. Then plug the unit back in and test You: ok Paul: Disconnect all of the speaker wires from the rear of the receiver. Use a Q-Tip lightly moistened with alcohol (not dripping) and clean around the jacks. Wait approximately five minutes for the alcohol to dry then try to power on the receiver. You: ok Paul: Please ensure that the power is off in the receiver before connecting or disconnecting your speakers. You: ok Paul: Power off the receiver and connect the main left and right speaker wires (for those models with both an A and B speaker set, test set A, then B individually). Power on the receiver. If the receiver powers on, continue connecting one pair of speakers at a time to find which speaker (or set of speakers) is causing the problem. You: ok Paul: If the receiver does not power with the main speakers connected, check the speaker wires for any visible shorts or damaged shielding. Replace these wires and reconnect them to the receiver. You: ok Paul: If the receiver still does not power on after checking the wires, verify the speaker impedance rating. Check that you have selected the correct impedance on the rear of the receiver. Sony receivers are not compatible with speakers rated below 4 ohms. You: ok Paul: If the receiver is played back at maximum volume level, even for a short period, it may enter the protect mode. Maximum volume will cause the receiver to run very hot and may fully drain the output capacitors, causing the receiver to enter the protect mode. You: i had just turned it on You: played for a second You: went to protect mode Paul: If the problem persists once you have tried the above, we would recommend that you have the unit evaluated atone of our SonyY Factory Service Centers. You: this unit has already made one trip for repair You: i am not very happy with it Paul: I am sorry .I understand your concern. You: this flaw is apparent. There are complaints similar to mine posted all over the internet