Well the audio circuit has finally failed on your TV set. You will need to replace the main board on it. That's the one with all the input jacks on it.
Part number is 934C335005
Hmm, looks like they are out of stock right now....
Wow, seems everybody is out of stock, so it's likely to be on National Backorder and unavailable for 4-6 weeks possibly.
Of course it could come in later this week. But that's hard to know.
Anyways, use that part number I gave you, and simply use it to Google the part suppliers, and get one.
Now, replacing the board is fairly simple. You should lay the TV face down on a blanked table. Remove all the screws in the rear cover and pull the rear cover off.
The board you will be replacing has several Locking connectors, so squeeze the tabs and waddle the connectors off. Then remove the screws on the board. get the now board out, and swap any trim plates over to the new one. Screw it back in, plug the plugs back in, and put the rear cover back on.
You'll get your sound back...
If you have any questions, just ask
If you are finished, please press the ACCEPT button.
Tips are greatly appreciated !
You're right, there is a software download on your TV set. You must have had HDMI Issues.