Sorry to be so long in responding. I was up in Fort Wilderness where WiFi has yet to be discovered. Anyway, I tried shutting the power down. No change. Later, accidently it appears to be fixed. My wife, Cherrie, lighting the screen up, touched the right bottom corner, where the "Preferences" selection was, and all worked normal again.
Normally I start the screen by touching the top right and my wife the bottom middle. So, I will describe the issue in case anybody runs into it.
Problem: Touch Screen Issue.
Description: Selections along the bottom work okay from left to right until you reach "Gen". Nothing happens when "Gen" is selected. Push the next one "Tanks" and the "Gen" selection appears. Select "Pref" and the "Tank" appears. "Pref" selection is not available. In addition, there was a couple of sub-selections, like the "EMS" on/off that did not toogle.
Correction: From the standby black screen, touch the right bottom corner that "Pref" would be. Screen should light with "Pref" selected.
Conclusion: This seemed to have fixed it, at least it did for me. Thought I would share it for others to try if they are faced with a similar issue.
Thanks for the help guys!
Peter