When these highly integrated computer controlled systems work, they are wonderful...until any 'one' thing becomes marginal
Then the whole system can flake out and most mechanics just change out components and sub-systems...until the cost is so high as Kevin states and/or they create even more problems so they go in circles trying to find whatever it is
Sometimes it is best if the offending component or sub-system completely fails and they fix it before that takes down other components or sub-systems
One reason I'm not in a hurry to get another newer TV