Hi, I have a 50-inch 4K Lg and for now the audio went out and I no longer return it to the factory settings, I checked the volume and everything is fine but still no audio how much would the repair cost be?

They would be able to give you a free estimate if you drop it off. Since there are different reasons things like that happen it's hard to give the cost without seeing the TV

I can never address the cost to repair it without troubleshooting it on my workbench to determine exactly what has failed and what my own costs would be. We do not charge for that service and the estimate is free but cost of repair is almost always much less than the cost to replace it, even at the low prices for new sets today. Right now I am running about 3 days behind, it would take at least that long from the time you brought it in until I could give you an estimate.