I FINALLY got a response from Yamaha.
I am not able to change, bass, trebble, sound parameters, etc., as it won't let me access the controls.
The Yamaha tech lad said to hook up component cables directly to the TV, then choose "component" on the TV source. That should "Key word, SHOULD" allow me to view the menus for adjustments of various atributes.
Whew. This HT stuff will drive a person crazy. Thanks for your help.
Now let's see if it works.
-John