Samsung CHA4217L Service Manual page 20

6 Alignment and Adjustments
CONDITIONS
Measurement instrument: Color analyzer
Scanning frequency:
Display image:
Brightness:
Contrast:
PROCEDURE
1. Display the full white pattern.
2. Adjust R-Gain and B-Gain so that the video is
white.
(x = 0.283 ± 0.02 and y = 0.298 ± 0.02)
6-3-5 White Balance Fine Adjustment
CONDITIONS
Measurement instrument: Color analyzer
Scanning frequency:
Display image:
X-Y coordinates:
PROCEDURE
1. Adjust the Contrast control so that the
brightness of the video is about 5 ft-L.
2. Check whether the white coordinates of the
video meet the specification above. If they do
not, adjust them so that they do.
3. Adjust the Contrast to maximum luminance.
4. Check whether the white coordinates still
meet the specification above. If they do not,
adjust them so that they do.
6-3-6 ABL Point Adjustment
CONDITIONS
Measurement instrument: Color analyzer
Scanning frequency:
Display image:
Brightness:
Contrast:
PROCEDURE
Adjust ABL so that the brightness level is
35 ± 1 ft-L.
6-6
53.7 kHz/85 Hz (15Ó)
43.3 kHz/85 Hz (14Ó)
Full white pattern
Maximum
Maximum
53.7 kHz/85 Hz (15Ó)
43.3 kHz/85 Hz (14Ó)
Full white pattern
x = 0.283 ± 0.02
y = 0.298 ± 0.02
53.7 kHz/85 Hz (15Ó)
43.3 kHz/85 Hz (14Ó)
Full white pattern
Maximum
Maximum
6-3-7 Focus Adjustment
CONDITIONS
Measurement instrument: Color analyzer
Scanning frequency:
Display image:
Brightness:
Contrast:
PROCEDURE
1. Adjust the Focus VR on the FBT to display the
sharpest image possible.
2. Use Locktite to seal the Focus VR in position.
6-3-8 Luminance Uniformity Check
CONDITIONS
Measurement instrument: Color analyzer
Scanning frequency:
Display image:
Brightness:
PROCEDURE
Measure luminance at nine points on the display
screen: top left corner, top center, top right corner,
center row left side, center, center row right side,
bottom left corner, bottom center, and bottom
right corner.
53.7 kHz/85 Hz (15Ó)
43.3 kHz/85 Hz (14Ó)
ÒHÓ character pattern
Maximum
Maximum
53.7 kHz/85 Hz (15Ó)
43.3 kHz/85 Hz (14Ó)
White flat field
Cut off point at 30 ft-L
CHA42*7L/5**7L