I have the SR6004 which I bought last year. I had used it minimally for only 7 months and came this problem. It goes to protect mode at only -23db volume with or without speaker loads. Inside were no premium parts. Power transformer is not massive. I now have the Onkyo TX-NR809 which for me is way more better than the 6004. In audio, the 6004 is I think only +5 and is way way behind the 809 in movies. Since I started this hobby in the early 90's, I always was a Marantz user and I still even have my first Marantz SR-82 which until today sings beautifully. Try to listen to the 809. But it all boils down to each own personal preference.