Samsung UN55ES8000G E-Manual page 704

either your Timer settings or your Eco
friendly No Signal Power Off feature.
First make sure Sleep Timer is not
accidentally set. The Sleep Timer turns
off the TV automatically after a certain
period of time has passed.
Œ
Sleep
Sleep Timer
If the Sleep Timer is not activated, you
may have engaged the No Signal Power
Off or Auto Power Off feature.
Timer: System
→ →
Time