How do I adjust the sleep timer and power off settings to save energy on the ET-3850?

To change the sleep timer, press the home button, select Settings > General Settings > Basic Settings > Sleep Timer, then press the + or – button to adjust the number of minutes. To set an automatic power off, go to Settings > General Settings > Basic Settings > Power Off Timer, and select a time period between 30 minutes and 12 hours. (Page 25)