Samsung UN55ES6580FXZA - Manual (Page 609)

If your Samsung TV appears to turn off
by itself, there may be an issue with
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.
ΠSleep Timer : System
→
Time
→
Sleep Timer
If the Sleep Timer is not activated, you