Alignment and Adjustments
4-4-6 F.S. (Fail Safe) Circuit Check4-4-8 Lens Focus Adjustment
Note : The F.S. Circuit check must be performed PRECAUTIONS
after servicing.
1. Do this adjustment after the static focus
1. Turn on the TV.adjustment and the tilt adjustment.
2. Select the OSTANDARD� video mode.2. Select the OSTANDARD� video mode.
(Contrast:100, Brightness:50)
3. Short F/S Test point (located on the SUB PCB).
Then, both sound and picture disappear.3. Input a crosshatch pattern.
(Note: Even if the shorted terminals are
removed, both sound andADJUSTMENT
picture do not appear. This proves the F.S.
circuit is working. )1. Loosen the lens screws.
4. To restore both sound and picture, turn off the2. Cover the two lenses that are not being
TV and reset it after about 30 seconds.adjusted.
4-4-7 Static Focus Adjustment3. Adjust the lens, observing the color aberration
vertically and horizontally within 3 blocks of
PRECAUTIONthe center of the crosshatch pattern.
1. Select the OSTANDARD� video mode.4. When the lens is turned clockwise, the color
aberration will change as follows:
2. Input a crosshatch pattern.
LensColor Aberration Change
3. Cover the lenses that are not being adjusted.R Orange - Crimson
G Blue - Red
4. Connect a convergence jig and read data.B Purple - Green
5. Adjust the lens for best focus.5. Green lens adjustment:
(See Fig, 4-1, next page)Set the lens at the point where Blue just
changes to Red. If the color aberration is
STATIC FOCUS (CONTINUED)irregular throughout the picture screen, adjust
the lens to show Red color aberration
Vary the focus pack VR (Red, Blue) on the(approximately 1~3 mm area) within a 3-block
front cabinet. Adjust the TV for best possiblegrid around the horizontal center-line. If the
focus around the center of the crosshatchcolor aberration is irregular, adjust the lens as
pattern, without losing overall screen balance.shown in the diagram below. (Accurate
Figure Crosshatch Pattern alignment of Green is important for overall
Examine these points together.color quality.)
6. Red lens adjustment
Set the Red lens at the point where Orange
becomes Crimson.
7. Blue lens adjustment
Set the Blue lens at the point where Purple
becomes Green.
Examine these points togetherP
Fig. 4-1 Crosshatch Pattern.L1L2
RED ABERRATION BLUE ABERRATION
L1, L2 _< P
Fig. 4-2 Color Aberration
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