Question Activating 5.1 channel on Yamaha RX-V1800

Aug 8, 2019
Hi all,

Going to format that post as best as possible, hopefully everything is clear.

My equipment
  1. Pioneer Elite Plasma TV (paired with the Pioneer PRO-R06U).
  2. Yamaha Receiver RX-V1800
  3. Xfinity Cable box (latest)
  4. 5.1 surround sound setup all wired into the Yamaha Receiver.
The Problem
I am unable to activate the 5.1 channel (the receiver just shows the L/R channel). I have read other threads and did some research but this situation/setup I believe is a bit unique.​
What I’ve Tried
  1. From what I’ve learned (totally might have this a bit wrong), is that 5.1 and above can only be achieved using either an optical jack, HDMI, or a coaxial cable. So I right now have the Xfinity box wired with an optical out into the receiver, and the 3 video component cables going from the receiver to the xfinity box as well. To connect the receiver to the tv, I have an hdmi cable going from the “HDMI out” of the Yamaha into the pioneer media receiver’s “input 1”. Using this method, I am able to clearly hear all speakers, and perhaps even an emulated surround sound mode Yamaha has for stereo, but the receiver still only shows the 2 channels. The set menu reads “2/0/——-“ which tells me that the other channels are not being recognized somehow. Even with that, every speaker and the subwoofer has been tested with the setup menu and all work and are properly labeled and recognized by the receiver.
  2. I then learned that HDMI is the best way to transmit video/audio and have the highest quality etc. So I took out the component cables and optical and wired HDMI, I also changed the input assignments on the set menu to allow for the cable box to be recognized. I even tried other devices and was unsuccessful on any hdmi input.
  1. Since I am able to get audio/video through the setup with component cables and optical-(the hdmi issue might be a non related different problem) I am trying everything I can to get the receiver to connect with the other channels. When I switch the receiver input to “multichannel” all of the speakers are recognized and the icons appear on the receiver-which tells me I must be missing a step in terms of connections or something.
Any insight on this would be greatly appreciated, I’ve spent days on this trying to fix everything for parents before I go back to school!