I have had a problem with my Denon x4000 AVR--after unplugging headphones, the speakers remain muted. I recorded a video of the problem before I sent it to United Radio for warranty service. I uploaded the video to youtube, and I included the URL for the video on the sheet I sent in with the unit.
I got an email from United Radio saying that they couldn't reproduce the problem. I emailed back, "Tell the technician to watch the video." When I checked the repair status a few days later, I saw they were waiting for parts.
Moral of the story: If you can get a video of a malfunction, you're more likely to get the service center to find and fix the problem.
I wish I had done this when I sent the unit to Panurgy a year ago for the shutdown/flashing red problem; they couldn't duplicate it, but somehow the problem hasn't recurred since it came back. I hope it doesn't start up again when the warranty runs out.
AT&T U-Verse Northeast Ohio
Denon x4000, Carver m1.0t, Samsung LED TV, B&W 704 mains, two M&K subwoofers, Oppo 103, Roku 2, etc.
Headphone system: Sennheiser HD600, AKG K702, Hifiman HE-400i, Marantz HD-DAC1 (also used for music playback in the main system, Marantz CD5004, Denon DVD-3910