Input mode settings?
have you assigned input sources to input connections? For example, input source is your DVD player and then you'll assign HDMI1 as your input connector (as long as your cable is installed to input 1). I have a denon 1908 and it took me a while before I had configured the receiver by assigning the different inputs I had going into it. I had a dvd player, tv audio, and a video game system audio going to the receiver. I had to assign each device to whichever cables I had going into it by the connection. I hope I could help. Not trying to second guess anything you've done, but I understand your frutstration.