Scanner Basics > Control Panel > Basic Screen Composition Control Panel Buttons and Light Basic Screen Composition 21 A Power button/ light Turns the scanner on or off. Do not turn of fthe scanner while the light is flashing because the scanner is operating or processing a data. B – LCD Screen Tap the screen to select menus or make settings. A Indicates the scanner status as icons. Select the icon to check the current settings or access each setting menu. B Displays menus. You can add menu icons and change the display order. C Displays the presets list. You can load your presets and register new presets. D Switch tabs.