Samsung SPT51A Service Manual page 18

Alignment and Adjustments
5-5 Lens Focus and Static Focus
Adjustment
5-5-1 Static Focus (Electric Focus)
PREPARATION
1. Select the "STANDARD" video mode.
2. Input a crosshatch pattern.
3. Cover the lenses that are not being adjusted.
4. Connect a convergence jig and read data.
5. Adjust the lens for best focus.
ADJUSTMENT
Vary the focus pack VR (Red, Blue) on the front
cabinet. Adjust the TV for best possible focus
around the center of the crosshatch pattern,
without losing overall screen balance.
Fig. 5-2 Crosshatch Pattern. Examine these points together
Fig. 5-3 Color Aberration
5-2
5-5-2 Lens Focus
PREPARATION
1. Do this adjustment after the static focus
adjustment .
2. Select the " STANDARD" video mode.
(Contrast: 64, Brightness: 32)
3. Input a cross hatch pattern.
ADJUSTMENT
1. Loosen the lens screws.
2. Cover the two lenses that are not being
adjusted.
3. Adjust the lens, observing the color aberration
vertically and horizontally within 3 blocks of
the center of the crosshatch pattern.
4. When the lens is turned clockwise, the color
aberration will change as follows:
Lens Color Aberration Change
R Orange —- Crimson
G Blue
B Purple —- Green
5. Green lens adjustment:
Set the lens at the point where Blue just
changes to Red. If the color aberration is
irregular throughout the picture screen,
adjust the lens to show Red within a 3-block
grid around the horizontal center-line.
Observe the the color aberration near the
intersection points of the horizontal and
vertical lines (approximately 1 - 3 mm area).
If the aberration is irregular, adjust the lens as
shown in the diagram below. (Accurate
alignment of Green is important for overall
color quality.)
6. Set the Red lens at the point where Orange
becomes Crimson.
7. Set the Blue lens at the point where Purple
becomes Green.
—- Red
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