White Balance Adjustment - Philips 40PFL5505D/F7 Service Manual

The White Balance Adjustment should be
performed when replacing the LCD Panel
or Digital Main CBA Unit.

2. White Balance Adjustment

Purpose: To mix red, green and blue beams correctly
for pure white.
Symptom of Misadjustment: White becomes bluish
or reddish.
Test Point Adj. Point
[CH] + or -
Screen
button
M. EQ.
Pattern Generator,
Color analyzer
Figure
To avoid interference from ambinent
light, this adjustment should be
performed in a dark room.
Perpendicularity
L = 3 cm
INPUT: WHITE 70%
1. Operate the unit for more than 60 minutes.
2. Input the White Raster (70%=70IRE).
3. Set the color analyzer to the CHROMA mode and
bring the optical receptor to the center on the
LCD-Panel surface after 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 [VOL] - button on the
remote control unit and select "C/D" mode.
Mode Input
White Raster
C/D
(APL 70%)
Spec.
x= 0.272 ± 0.003
y= 0.278 ± 0.003
Color Analyzer
5. [CUTOFF]
Press [1] button to select "COR" for Red Cutoff
adjustment. Press [2] button to select "COG" for
Green Cutoff adjustment. Press [3] button to select
"COB" for Blue Cutoff adjustment.
[DRIVE]
Press [4] button to select "DR" for Red Drive
adjustment. Press [5] button to select "DG" for
Green Drive adjustment. Press [6] button to select
"DB" for Blue Drive adjustment.
6. Adjust the data of "1(COR)", "2(COG)" and
"3(COB)" to 0 by using [CH] - or + button.
7. Adjust the data of "4(DR)", "5(DG)" and "6(DB)" to
63 by using [CH] - or + button.
8. Adjust Drive so that the color temperature
becomes 12000°K (x= 0.272 / y= 0.278 ±0.003).
9. Adjust the highest data from the "4(DR)", "5(DG)"
and "6(DB)" to 127 by using [CH] - or + button.
To adjust the rest of the two drive data, calculate
the data by the following method.
{ (128 + A) x 255 / (128 + B) } - 128
A: One of two data, except for the highest drive
data, you would like to calculate.
B: The highest drive data.
For example:
(When the current data says DR=70, DG=63 and
DB=59.)
1: Adjust the highest data to 127.
In this case, adjust the DR to 127.
2: Calculate the DG data.
{(128+63)x255/(128+70)}-128=117.9
The result for the DG data is 118.
3: Calculate the DB data.
{(128+59)x255/(128+70)}-128=112.8
The result for the DG data is 113.
10. To cancel or to exit from the White Balance
Adjustment, press [PREV. CH] button.
5-2 PL10.4EA