Samsung PN64E8000 manual ŒŒ Sleep Timer System → Time →

off the TV automatically after a certain period of time has passed.

ŒŒ Sleep Timer: System → Time →

Sleep Timer

If the Sleep Timer is not activated, you may have engaged the No Signal Power Off or Auto Power Off feature.

ŒŒ No Signal Power Off: System → Eco Solution → No Signal Power Off

ŒŒ Auto Power Off: System → Eco

Solution → Auto Power Off