DOWN 
1) Adjusts audio volume or selects Mute option (if no OSD is currently displayed on screen)
2) Decreases value of OSD adjustment choice
SELECT 1) Selects Analog or Digital
2)Selects adjustment choices from the OSD menus.
POWER Turns the monitor on or off.
After adjusting the values, the monitor automatically saves the changes.
OSD Lock/Unlock
You can lock and unlock the OSD feature. The monitor is shipped with the OSD unlocked, no OSD can be displayed or used.
To lock the OSD:
1Press the MENU button and UP button simultaneously for 2 seconds. A window appears displaying “OSD Unlock.”
2Continue to hold the buttons down for another 2 seconds and the window toggles to “OSD Lock.”
Power Lock/Unlock
You can lock and unlock the Power feature. When the power is locked, pressing the power switch does not turn off the monitor. The monitor is shipped with the power unlocked.
To lock the power:
1Press the MENU button and the DOWN button simultaneously for 2 seconds. A window appears displaying “Power Unlock.”
2Continue to hold the buttons down for another 2 seconds and the window toggles to “Power Lock.”
NOTE: By default, the OSD screen disappears if no input activities are detected for 30 seconds.
Elo TouchSystems 1900L User Guide 17