Had a 42 “ LG and after about 18 months screen would go black but sound was still on , rang LG but wouldn’t do anything as it was out of warranty. After 5 years of messing around with it (turning it off and on ) decided to buy a 50” Panasonic which is brilliant ,in the meantime I thought I would take the back off the LG and give it a good clean and push all the connections on securely and tighten all screws ( some of which were quite loose ) we now have the LG on the kitchen wall and it has not gone off at all and that’s after 1 week , it worked for me maybe it could work for you ,good luck