That might clear things up, especially if you say none of the connections have been altered and it used to work before.
If that still doesn't work, I can map out how I would connect everything from scratch.
I have no audio through the TV or through the receiver.
Yesterday I turned on my Sharp TV and switched the Yamaha HTR-5740 reciever to the DTV/CBL input BUT SUDDENLY THERE WAS NO AUDIO from either device. The audio works for the other inputs, like TUNER and V-AUX. There is also no audio through the TV, which I usually keep on mute, but it did work previously.
These functions have been working and now they suddenly don't so it is not a setup issue.
This is not a LAN button issue.
I have tried going through the Xfinity audio setup to Select to Optimize.
I do not think the receiver has HDMI.
I also have a Motorola cable box for Xfinity.
Any suggestions would be greatly appreciated!
And thanks for help in the past. This is surprisingly the first time I've had to post about an issue.
Good luck with any of your technical difficulties!