Facing TV Problems? Ask a TV Technician.
Hi, I'm Nathan.Sorry to hear that you're having trouble with this but I'll do my best to help you.
This actually isn't just a matter of the codes, if it is controlling anything on the receiver (power, etc) then you should be fine there,
instead the issue is that you reprogrammed the remote or it was somehow reset. You now have to change the control mode of the comcast remote, if you look in the comcast programming for your particular remote, you should see something called "aux mode" or "amp mode", which has the effect of telling the remote what device the volume keys should default to, and you want it to go to the receiver not the tv. Once that aux volume setting is enabled, you should be all set, but let me know if you get stuck and I'll help you through.
No I'm referring to a programming mode,
when done properly, when you hit volume the aux button should actually light up each time you press volume (instead of tv) which would confirm the source of the problem.
This is a switching mode issue that has to be programmed into the remote, but you'll have to check the documentation for your specific comcast remote for that process, they have 100+ different remote models.