I'm relatively new to the home theater market, and was hoping someone here could help me out. I have an older Onkyo TX-SV454 receiver that I've been using mainly for music in my office (I run MP3s off my computer and a CD player into it). It is hooked up to a pair of Monitor Audio Silver 7s. Anyway, out of the blue the other day, I turn it on, and it almost immediately displays "Protect" on the display, then shuts itself off. Nothing was changed from the way I had it running the previous year. I checked all the wiring (all Monster Cable of some sort or another), and it was intact, with no loose strands or anything that could have been causing a short. So I completely disconnected everything - RCAs, speaker wire, everything - and it still displays "Protect", even with nothing attached to it (and the volume turned all the way down). I opened it up to see if there was anything obvious and to check the fuse. Fuse was fine, and the wiring looked normal. There are no Onkyo service centers anywhere near me, unfortunately, so I'm looking for advice. Anything would be helpful - if it's something I can't fix easily, I'm going to sell it and buy a new receiver. Thanks in advance.