Except to add a note from a colleague about another one of these that I had forgotten about --
After the Panasonic service department kept this unit for several weeks and could not find any problem with it, they sent it back. We could then not complete a channel scan at startup. It ran at a different percentage of the scan each time, but never completed.
A good answer is easier with a clear question giving the make and model of everything. "The biggest problem in communication is the illusion that it has taken place." -- G. “Bernie” Shaw