Lionel got back to me on the Zephyr issue described above. They suggest the Railsounds Lite board ($79) or the RCMC ($120). The Tech indicated he would attempt to get a more definitive answer from his Director.
Given John's explanation here and his subsequent most helpful fix for the H 10 with the speaker replacement...I'm inclined to think the Railsounds Lite board....but I am not sure.
Given the symptoms Gents.....which board would you replace?
Thank You
Dave