No audio at all

there is no internal switch inside the tv to fix the problem. have you unplug the tv for 5 minute and see if it reset. if that don't work is in internal circuit sound board unit, sound is a bit difficult to diagnose and fix yourself, Any tv shop can fix the issue under 100 buck replacing the board, or you can bypass the sound by using RCA out put from tv than to an amp OR spend 50.00 and get a computer speakers that has an amprefier built into it and plug it in head phone from your tv and you can control the volume from computer speaker unit. My friend has the almost the same issue that the tv wont change channel by remote or from tv unit itself, so we use cable box and the remote to by pass the problem. I hope that help a bit..good luck!