My dad was using a wireless headset on his TV, and one day he unplugged it and there was no audio coming from the TV speakers. So we're thinking that the headphone output jack broke somehow, and the TV thinks headphones are still connected. When we went into the audio settings it said "can't adjust settings while headphones are in use" or something like that. Even plugging in the headphones produces no sound.

Should I try opening it up and seeing if there's something broken with the output? Take it to a repair shop? Or, would it be possible to connect a digital-to-analog converter to the optical audio output and connect to external speakers?

My dad called Best Buy and they said they'll come to the house and repair it, but the trip alone is $100, and my dad thinks by the end of it they'll charge as much as a new TV would cost.

What to do?

Some laptops have an issue where the switch that detects headphones gets stuck. Usually because iPhone headphones were inserted (it is a slightly longer connector because of the microphone.)

I don't know if this what happened to your TV, but the solution to the laptop problem is to plug the headphones in a few times to hopefully "unstick" the switch. Maybe even try poking a small screwdriver or paper clip in the jack a few times.

I accidentally set my tv to headphone output. Didn't matter that no headphones were plugges in... I couldn't get sound. I had to go in and change the sound back to tthe TV's speakers. Give that a try?

No dice. Tried playing with the headphone jack without any luck. And the TV won't even let me get into the audio settings as long as it thinks a headset is plugged in.

I'm wondering if the switch inside the headphone jack is broken and the headphone jack needs to be replaced. I tried searching online for a replacement main board for it, but it's out of stock everywhere. I'm no expert solderer, but I think I can replace it if I can find the appropriate replacement. However, I'm wondering if it'll function if I just remove the jack.

Fixed it: Apparently TVs have built in service menus. I was able to download an app called AnyMote and used the IR blaster on my dad's phone to get into that menu and turn off the headphone jack. TV appears to be working fine now.

For more info there's a post here that details how to use it: https://www.cnet.com/forums/discussions/lg-tv-sound-only-via-headphone-jack-596549/