Sylvania 6842THG, Service Manual

Page: 31 / 123

1-6-4 L0700EA
6. White Balance Adjustment
Purpose: To mix red, green and blue beams correctly
for pure white.
Symptom of Misadjustment: White becomes bluish
or reddish.
Notes:
- Use service remote control unit.
- This adjustment should be performed in Video 1
mode.
1. Operate the unit more than 20 minutes.
2. Input the gray scale pattern signal (5 scales) from
Composite AV Input (1) video jack (Video1).
3. Set the color analyzer to the CHROMA mode and
after zero point calibration, for high light
adjustment, bring the optical receptor to the 2nd
scale as shown below.
4. Enter the Service mode.
5. Enter the component adjustment mode, press
[VOL
p
] button once on the service remote
control unit.
6. Press [4] button on the service remote control unit
for Red adjustment. Press [6] button on the service
remote control unit for Blue adjustment.
7. In each color mode, press [CH
o
/
p
] buttons to
adjust the values of color.
8. Adjust Red and Blue color so that the temperature
becomes 12000
°
K-5MPCD (x: 272 / y: 278) ±3%.
9. For low light adjustment, bring the optical receptor
to the 4th scale as shown below.
10. Press [1] button on the service remote control unit
for Red adjustment. Press [3] button on the service
remote control unit for Blue adjustment.
11. In each color mode, press [CH
o
/
p
] buttons to
adjust the values of color.
12. Adjust Red and Blue color so that the temperature
becomes 12000
°
K-5MPCD (x: 272 / y: 278) ±3%.
13. Check adjustment value in high light adjustment
again. If adjustment value is not within
specification, repeat steps 2 to 8.
14. To enter the adjustment mode in the Composite
mode (Video 1 mode), press [VOL
p
] button once
on the service remote control unit.
Test
Point
Adj.
Point
Mode Input
Screen
[CH
o
/
p
]
buttons
Video 1
Gray scale
pattern signal
(5 scales)
M. EQ. Spec.
Pattern Generator,
Color analyzer
See below
Figure
Fig. 8
Fig. 9
Color Analyzer
2nd gray scale
Fig. 10
4th gray scale