How do I adjust the sleep timer to save power on the ET-3850U?

Press the home button, then select Settings > General Settings > Basic Settings > Sleep Timer. Press the + or – button to increase or decrease the number of minutes, or press OK to use the on-screen keypad to enter a value, then select Done. You can also configure the Power Off Timer by selecting Power Off Timer and choosing a time period between 30 minutes and 12 hours. (Page 25)