JVC LT-19D200 Service Manual page 15

4.6 VCOM ADJUSTMENT
Test Point
Screen
M. EQ.
Color analyzer
To avoid interference from ambinent
light, this adjustment should be
performed in a dark room.
Perpendicularity
L = 3 cm
(1) Operate the unit for more than 20 minutes.
(2) Set the color analyzer and bring the optical receptor to the
center on the LCD-Panel surface after zero point calibra-
tion as shown above. Note: The optical receptor must be
set perpendicularly to the LCD Panel surface.
(3) Enter the Service mode.
(4) Press [3] button on the service remote control unit.
(5) Press [CHANNEL UP/DOWN] buttons on the service re-
mote control unit so that the color analyzer value becomes
minimum.
Adj. Point
[CHANNEL UP/DOWN ]
buttons
Spec.
See below
Figure
Color Analyzer
4.7 WHITE BALANCE ADJUSTMENT
The white balance adjustment should be performed when
replacing the LCD Panel or Digital PWB.
Purpose: To mix red, green and blue beams correctly for pure
white.
Symptom of Misadjustment: White becomes bluish or reddish.
Test Point Adj. Point
[VOLUME
[VIDEO1]
Screen DOWN]
button
M. EQ.
Pattern Generator,
Color analyzer
To avoid interference from ambinent
light, this adjustment should be
performed in a dark room.
Perpendicularity
L = 3 cm
INPUT: WHITE 70%, 40%
(1) Operate the unit for more than 20 minutes.
(2) Input the White Raster(70%=70IRE, 40%=40IRE).
INPUT SIGNAL
0IRE
Low
Light
100IRE
40%=40IRE
(3) Set the color analyzer to the CHROMA mode and bring the
optical receptor to the center on the LCD-Panel surface af-
ter zero point calibration as shown above.
Note: The optical receptor must be set perpendicularly to
the LCD Panel surface.
(4) Enter the Service mode. Press [VOLUME DOWN] button
on the service remote control unit and select "C/D" mode.
(5) [CUTOFF]
Press [1] button to select "COR" for Red Cutoff adjustment.
Press [3] button to select "COB" for Blue Cutoff adjustment.
[DRIVE]
Press [4] button to select "DR" for Red Drive adjustment.
Press [6] button to select "DB" for Blue Drive adjustment.
(6) In each color mode, press [CHANNEL UP/DOWN] buttons
to adjust the values of color.
(7) Adjust Cutoff and Drive so that the color temperature be-
comes 12000°K (x= 0.272 / y= 0.278 ±0.005).
Mode Input
White Raster
(APL 70%)
C/D
or
(APL 40%)
Spec.
x= 0.272 ± 0.005
y= 0.278 ± 0.005
Figure
Color Analyzer
0IRE
Hight
Light
100IRE
70%=70IRE
(No.YA711<Rev.002>)1-15