When turning on my 32" Magnavox, I get a picture but no sound. I also notice that the channel randomly changes on the TV from Ch 2 to 99 or Ch 99 to 2 and when doing so it also displays Mono. I am able to route Red/White sound cables to my Tuner to get TV sound out stereo speakers but I am not able to do this for DVD or Video Games.

I've gone into the TV menu and tried changing sound setting but that didn't do anyhthing. Any ideas?