DVR menu screen not appearing on TV
I own a Denon AVR-2311CI. Has worked beautifully for 4+ years. However, I can no longer see the Denon menu screen on my TV when I am listening to music. My set up is Xfinity Cable Box (HDMI), Panasonic Bluray (HDMI) and Squeezebox digital music source (Toslink)>>Denon AVR-2311CI (HDMI) >>Vizio TV. The AVR does the switching. I can see the AVR menu when watching cable and Bluray, but when I switch the Denon to the music source, I get nothing on the screen, not the DENON banner, nor the menu screen. Until a week ago I could see the menu when switched to any of these three sources, but for some reason it has stopped for the Squeezebox. Audio on this source is fine. On the TV, it shows a 720P input signal when watching cable, 1080p when watching Bluray, and 480i when switched to the Squeezebox, so it would appear that a video signal is getting through. So my guess is that it is a setting within the AVR, but I can't find it.
I have an almost identical setup in another room (It is a Denon AVR-891), and everything works fine. I have spent hours trying to figure this out, mostly making sure the settings on the AVR are as the same as one the AVR-891. Any ideas?