Here's one way to arrange things. We're going to use the Watch TV Combo button so that some buttons will control the TV and some will control the STB. First make sure you have a setup code assigned to the STB button, either by searching or by entering setup code 1982 (I guess that is correct for the Xfinity box.) Then assign the same EFCs to the Red Green and Orange buttons, but make these effective in STB mode by adding an additional step to the previous 994 procedure. 1. Press Setup until 2 blinks 2. Press TV - This button blinks once as you push it. 3. Enter 994 - It will blink once for 9, then 9, and twice for 4. 4. Press Setup 5. Press STB (this is the added step) 6. Enter the EFC 00193 (HDMI1) - enter 00193 7. Press RED Button 8. You get 2 blinks Now in either TV or STB mode, the color buttons should control the TV input.
At this point, if you press the TV Combo button briefly (it's the same button as Setup, so don't hold it) subsequent button presses of the Vol or Mute buttons will send a signal to the TV, while the other buttons will cause a signal to go to the cable box. If you need to use e.g. the arrow or Select/OK functions on the TV, press the TV button to revert to TV device mode.
In TV mode, you can toggle Power on the Vizio by pressing the Power button. In Combo mode, you need to hold the Power button for 2 seconds. By default in Combo mode, holding Power for 2 seconds will send toggle signals to both the Vizio and the Xfinity. You can stop the remote from sending power toggle to the cable box in Combo mode by: 1. Press Setup until 2 blinks 2. Press Setup briefly 3. Press STB 4. Press Power (should get 2 blinks)
Last thing: Set Volume Punchthrough to TV 1. Press Setup until 2 blinks 2. Enter 993 3. Press TV (should get 2 blinks) Setup in this way, the remote will control the TV volume in any of Combo, TV , or STB modes. In Combo or STB mode, all of the buttons except the Volume group and color buttons will control the Xfinity. In TV mode, any button which sends a signal will send it to the TV.