IR cross-signals to Onkyo LS3100??
I really apologize for the long post and detail as I've already posted this on Comcast's forums, but I'm pretty confident I'll get an answer here.
Here's my set-up:
JVC EM48FTR TV
Onkyo LS3100 2.1 audio system
Harmony 300 remote
First things first: last week I had DirecTV and had zero issues. The set-up then, as it is now, is HDMI from cable/SAT box to TV, PCM from TV to Onkyo. The remote is programmed to operate the Onkyo when in cable/SAT mode. About as simple as it gets.
I essentially swapped out the DirecTV box for the Comcast box, reprogrammed the Harmony remote, and now I have the strangest audio problem. If I turn the volume up, and then press any button on the remote for the cable box (channel up, menu, guide, etc.), the volume goes up. If I hit mute, each time I press a button to operate the cable box it activates the mute button.
Basically, whichever audio button was pressed last (up, down, or mute), that selection is "remembered" and is activated anytime I make a selection in cable mode.
I swapped out a DCT3412 for the current DCX3400 and both boxes have this same problem. I tried component video cables and analog audio cables, same problem. I tried running audio straight to the Onkyo and skipping the TV, same problem.
As it would appear that it's a programming problem on the remote, I wiped the remote clean and re-added all the devices. Same problem. I tried the Comcast remote and although it isn't programmed to operate the Onkyo system, it caused the same problem which makes no sense. I did a factory reset on the Comcast remote, same problem.
After reading online I thought it might be a problem with IR interference. I screwed around with that for a while but that doesn't appear to be the case.
I disconnected the PCM line and changed the audio to go through the TV, but the volume at that point wouldn't change. It just muted/unmuted every time I changed the volume for the cable box. When I changed the remote to operate the TV volume, nothing happened at all.
The audio settings on the box are advanced, light, matrix. Changing these doesn't appear to affect the problem at all.
As you might imagine, this is driving me crazy, especially as I've tried so many cabling/setting combinations and nothing's working. Help?!
And here is a recent update:
Ok, so I don't know enough about IR signals to make this statement without potentially sounding like a fool, but here goes: I think that the same signals required to operate the Comcast box(es) are unintentionally triggering my Onkyo box. I've reset my Comcast remote so that it only controls the Comcast box, and I've removed the Onkyo box from my Harmony remote. I then turned my Comcast box around so that I cannot control it with the remote, and when I'm in front of the TV and Onkyo box, any button I press on either remote in Cable mode causes my Onkyo box to turn the volume down.