Have a Vizio 50". The video works fine, but I have no sound. I tried the external audio jacks (both the RCA and 1/8"), but no sound from either (and yes, I changed the speaker settings from internal to external). After doing some research, though it was the main board as all the jacks and speakers come out of that control panel. However, replaced the main board and still no sound from the speakers or the external audio jacks. Any thoughts on what else I am missing? It is our only TV, don't really have the money to buy a new TV right now, and the wife is getting grumpy over not having TV. Thanks in advance for any help.