I have looked through the threads about other people's protect mode problems, and I found many helpful suggestions, but I still can't fix my problem. My Sony STR-DE597 receiver is less than 6 months old. It worked great for about 3 months, then it continually goes into protect mode after about 20 minutes of use. This will happen no matter what input I’m using, either an optical or an analog (RCA cable) connection, and will even happen when I use the FM tuner. Volume level or tone seems to make no difference, and I mainly use the receiver for soft background music. I only use two speakers and shut off all of other possible speaker configurations using the receiver’s menu, and this problem has occurred when I’ve hooked up the speakers as the A speakers AND the B speakers. I have even got it to go into protect mode using the FM tuner and having no speakers connected to it at all. I cannot immediately turn the receiver back on after it shuts off automatically—if I do, it will flash “PROTECT” again and shut off—but after five to ten minutes I can turn it on again, only to have it go into protect mode after another 20 minutes or so. I bought the receiver at Best Buy with an extended warranty. I brought the receiver into Best Buy twice, and they were unable to replicate the problem either time. Unfortunately, I don’t know exactly how they set it up to test it. When I set up the receiver again after the second time I brought it to Best Buy, it worked well for about a week before it starting regularly going into protect mode again. I noticed that the receiver was getting very hot on top of the cabinet towards the right side. So I added gold banana plugs to all of my speaker cables. After experimenting with the speaker setup, I found the following: hooking up the left speaker (of the A set) makes the receiver get hot. I also noticed that the left speaker will make a “popping” noise when I first turn the receiver on and the input is already on or if I immediately switch it to the tuner. The hotness and popping occurred with both of my speakers, using both speaker cables, as long as they were plugged into the left speaker jack. I thought I could conclude that it wasn’t my speakers or my connection, so I left the receiver running with only the right speaker plugged in (the A set)—the receiver didn’t get hot, but it still went into protect mode and shut off after about 10 minutes. So, I brought the receiver into an authorized Sony service center, and they, too, were unable to replicate the problem. They evidently had the tuner running for days. I’m really at a loss here. It doesn’t seem to be my setup (speakers/connections or inputs), so the only thing that I can think of is maybe the problem has something to do with electrical current, but I’ve tried the receiver in different outlets, some with power strips and surge protectors, some without, and the same problem occurs. I also tried plugged the receiver into the Automatic Voltage Regulator/Battery back-up surge protector I have for my computer. The "Wiring Fault" light on the power strip doesn't come on, so apparently the outlets I've tried are grounded. I'm going to get one of those electrical testers from a friend to test the outlets directly, but in the meantime I thought I'd post this to see if anyone has any suggestions. Could it be my speakers? They are still under warranty. I also got authorization from Sony to ship it to them--are they likely to send me a new/furbished unit, and is that going to end my problems? Any suggestions would be welome.