For many years, I have ran RCA cables from back of this flat screen, to my Carver preamp’s video 1 input. Recently, the signal went bye-bye. I tested all the pre-amp’s RCA inputs and all work properly. Thinking there might be an issue with the RCA audio out’s of Vizio, I bought an optical cable and an optical to RCA converter This did not work, leading me to believe the issue lies with the audio outputs on the Vizio. Has anyone encountered this? If so, what is the solution?