That cured my old issues with the Comcast grey remote.
Bob's solution may cost more but can be really great.
Upgraded my tv this year to a Vizio 4K smart tv from a Sony. Third component is a Sony receiver DVD combo. With the old Sony tv, my comcast remote would communicate with the Sony tv and receiver to control volume up and down and mute. now, the remote still communicates with the tv and receiver to turn on/off the mute, but will only turn the volume down but not up. Thoughts? This is taking some of the fun out of my new purchase. I have the grey DVR capable Comcast remote.