Acer AL2002 AL2002 Service Guide - Page 13

12 Go to cover page 4. FLAT PANEL: 4.1. General Requirements The panel used as the display device shall be a WSXGA resolution, 20" diagonal, TFT-LCD. 4.2. Panel Timings The controller included with the monitor shall translate all video timings from the CPU that meet the timing requirements listed in Panel specification into timings appropriate for the panel. Under no circumstances may the controller supply the panel with timings that may result in damage. The controller shall insulate the panel from the CPU, so that the panel shall always be driven per its own specification regardless of the timings being sent from the CPU. 4.3. Polarizer Hardness The outer face of the front polarizer panel shall be covered with a coating with a 3H hardness value, Haze 44% (AMLCD). 4.4. Backlight Requirements 4.4.1. General Requirements The backlight assembly shall be designed to support field replacement at the customer site or authorized service center. The lamps shall have a continuous operating life of at least 50,000 hours at 25oC. The operating life is defined as having ended when the illumination of light has reached 50% of the initial value. The lamps shall extend a sufficient amount from the edge of the light guide that sputtering over the life of the lamps shall not cause degradation of the luminance uniformity (such as non-illuminated bands along the edges of the display). 4.4.2. Lamps Startup Time The backlight lamps shall start within 3 sec. of the time the monitor power switch is pressed or the monitor is restarted from a power - down mode .The starting time shall stay below 3 sec. for the minimum expected life of the lamps. Test conditions are as follows: Ambient Light Temperature < 1.0 lux. 10oC Inactive Time 24 hours 4.5. Defects: 4.5.1. Visual Inspection The LCD panel shall be inspected with all pixels set to white, black, red, green, and blue. The color variation, brightness variation, and overall appearance must not be perceived as poor quality by Lite - On. Areas and / or parameters considered questionable shall be subjected to detailed measurements.