Mushvig

Hi! My TV turns itself off suddenly and then turns on after a while (several minutes) when I'm watching, for example, a movie in its relatively noisy or sound effects-heavy part. When connecting external sound speakers, this problem does not occur. TV software has been updated, the latest version. There are no other external devices connected to the TV, no problems with electricity/. What could be causing the problem and how can it be fixed? Thank you.