Hi! I have this LG tv and it is about 3-4 years old. It has developed an issue, that it shuts down the screen after a few hours of watch time. The sound and the power stays on. If you leave it for a few hours or overnight to "cool down", it works again for a few hours. If I have it on maximum power saving mode, so that the screen is very dim, it will work just fine. But if you put it on medium saving mode, for example, it does it again. Is it something related to overheating or smth?