Duplicate post. See https://www.cnet.com/forums/discussions/soundaudio-1/
Locked this one.
I have a 3 month old 43in LG smart tv. Just 2 days ago I lost audio on live tv. Using Netflix, or a dvd through the TV, I do have sound. But when I turn on Live tv through my HDMI 1, I have zero sound. I have tried a factory reset, and also unplugged the power cord and held the power button on the tv for 30 seconds (what an LG rep told me to do.) any ideas on how to fix the problem? Much thanks!