Pretty much all of the other posts are correct to an extent. When your receiver goes into, “Protect Mode,” it can be a number of problems… The following is a check list I suggest before purchasing a new receiver;
1. If you have changed the speakers in your system, make sure the new speakers are within the impedance range the Sony can handle. (Nothing under 6 ohms).
2. If you have recently installed a new cable DVR box, these suckers run extremely hot and should not be directly stacked on top or on bottom of the receiver. Ventilation is the key.
3. If for some reason you have recently turned the receiver around to install a new DVR or gaming station, chances are speaker wire leads were accidentally pulled out and are now touching one another which is shorting out the receiver.
4. If you have had a power surge, (and it doesn’t take much), it could have locked up a micro processor or blown an amplifier capacitor.
Thus, improper ventililation, power surges, and speaker wire shorts are the usual suspects. The easiest way to diagonose the problem is to first completely disconnect all speaker wires. With all wires disconnected, turn the unit on. If the unit still goes into, “Protect Mode,” chances are a capacitor or an IC board is shot due to a power surge.
Next, if the unit does NOT go into, “Protect Mode,” with all speaker wires disconnected, shut the unit off and begin to connect speaker wires one at a time. Every time you connect a single speaker wire, turn the unit on again. Repeat this process for all speaker wires one at a time. If at any point, (EXAMPLE: 3 speakers are now connected), if you hook up the 4th speaker and it goes into, “Protect Mode,” there’s either a problem with the speaker wire, or the speaker is blown which would cause a dead short.
continued on next post… ran out of room-