On my TV, my KDE desktop was too large. I.e., I could only see the top half of the main panel, the K menu was totally off the screen, etc.
What I discovered is that my TV has two 16:9 standard modes. Setting the TV to 16:9 standard2 made the entire KDE desktop visible. This then resulted in the on-screen orbiter floating in from the borders so had to re-run the video setup.