Let me start by saying good job for posting a link to the manual, very helpful. The answer is on pgs. 38 & 41, just explained poorly. You need to enter your set up menu by pushing amp to turn on the receiver, then set menu. Now use the down arrow to scroll down untill the word inputs shows up in the display. Now use the right and left arrows to toggle through your selections. What you want is to get to the digital coax, I believe it will be the third item in the list. Again use the up and down arrows to select the device you would like this input to be assigned to. In your case there is an option for DTV/CBL. Press a sound field button to exit. This post is the best I could figure with your manual. I hope it works for you, good luck.
