3-5 Hidden Key list No 1. Hidden Service Function -. After setting brightness and contrast '0' push the "Enter" button more than 5 seconds. -. Service Function appear. 2. Factory Reset -. While Menu is opened(any menu), press "enter" key over 5 seconds. -. Screen is flashing, then all menus return to the factory default. 3. Auto calibration To Analog video, In 16gray or any pattern using black and white and any mode.(16gray and XGA mode recommend) 1. Push the OSD Menu button to open the OSD. 2. Select language English. 3. Push enter button during 5 seconds. 4. Screen is flashed and auto calibration is completed. 4. OSD lock -. Press the menu key over 5 seconds, then OSD is locked . -. To unlocked the OSD, press the memu key over 5 seconds.