Acer P203 Service Manual page 7

ACER P203W
6
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1.3.8 Display Communications Channel
The monitor assembly shall provide a display
communications channel that conforms to VESA
DDC2Bi hardware requirements. This configuration
shall contain the 128-byte EDID file as specified by
VESA EDID standard.The monitor should not write to
the EDID file for the first two minutes of operation
following power-up UNLESS some action taken by the
user or the host CPU forces the write (for instance,
requesting the serial number via the OSD).
Furthermore, it is recommended that CMOS switches
be incorporated to isolate the DDC IC from outside
connections while the EDID Fault Management is
being updated. This is to prevent corruption of the data
by attempts to read the data while it is being changed.
1.3.9 Firmware Update Function (same ISP function)
The update firmware need through from the D-Sub
connector, use DDC I2C bus to do update firmware.
1.4 PANEL ELECTRICAL
1.4.1 General Requirements
The panel used as the display device shall be an
WSXGA resolution,20/22W, TFT-LCD.This panel shall
be approved for use in this monitor.
1.4.2 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 it's own specification regardless of the
timings being sent from the CPU.
1.4.3 Polarizer Hardness
The outer face of the front polarizer panel shall be
covered with a coating with a # 3 hardness value
1.4.4 Backlight Requirements
1.4.4.1 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 40,000 hours at 25. 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).
1. Product Specification (continued)
1.4.4.2 Lamps Startup Time
1.4.5 Defects
1.4.5.1 Visual Inspection
1.4.5.2 Display Degradation
1.4.5.3 Light Leakage
1.4.5.4 Allowable Defects
.
The backlight lamps shall start about 2 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 about 2 sec. for the
minimum expected life of the lamps.
Test conditions are as follows :
Ambient Light ----------------------
Temperature--------------------------
Inactive Time -----------------------
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 .
Over the life of the product , variation of the
parameters specified in Panel specification shall be
maintained within reasonable limits.The panel must
not exhibit any significant defects while in operation
( excluding the CCFL operation ).This does not in
any way change the warranty given by the panel
manufacturer .
Except for the active display area , there shall be no
light emission visible from any angle from any other
part of the display . For this test , the ambient
illumination must follow panel's specification.
No cosmetic defects are allowed except those
specified below.The conditions of visual inspections
are as follows :
For P20/22 W Series.
■
Viewing distance is to be approximately 35-50cm
■
Ambient illumination is to be 300 to 700 lux.
■
Viewing angle shall be at 90 degree.
■
Defects not apparent within one minute shall be
ignored.
< 1.0 lux
10 ℃
> 24 hours