I also had this issue, It's the led backlight has gone bad. Company will ask to change the entire panel assembly , for huge amount of money. Or ask to buy a Annual maintenance contract. Still expensive. Simply go to AliExpress website, buy led backlight bars and replace them. Or u can also buy individual LEDs there, and reflow/hot air solder it yourself. The LG company is fraud. The service guy took ₹3500, but on aliexpress it costs only ₹2000. Thank you, Good Luck.