Check whether the audio is muted by accidental press at remote control button. Enter its sound menu, and check it. If muted, as you know there will be no audio output. If not muted, check the speaker/s. If found OK; check and replace the damaged component/s at its audio output section circuit board. If needy, replace this board as card basis. If you wish to get some details; check the site linked here. Surf the site with patience. Pull up older posts. Surf the site with patience.
http://electronicshelponline.blogspot.com/
http://electro-medical.blogspot.com/