Hi there and welcome to Just Answer. Thanks for asking your question.
What we have to do is determine if it is your TV or if it is the TV signal.
How do you get your TV signal? Cable? Cable box? Satellite? Antenna?
That doesn't sound good.
Try this first. I have to rule out the easy stuff first.
Go into the on screen menu and into Audio. Check that the internal speakers are 'ON'.
Let me know.
Ok. I will have to research if there is a hard rest for this TV. I know there is for other larger LG LCD models.
I'll be back.