Purity And Convergence - Sanyo CZP1662 Service Manual

PURITY AND CONVERGENCE ADJUSTMENT
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CAUTION: The Convergence and Purity adjustments have been made at the factory. Readjustment should be
made only after picture tube or deflection yoke replacement, following the steps below
PURITY ADJUSTMENT
1.
Demagnetize the picture tube and receiver using an external
degaussing coil. When replacing picture tube or deflection
yoke, mount deflection yoke and purity - convergence
magnets assembly properly, see figures 1 and 4.
2.Turn Red and Blue guns off and provide only
Green raster.
Rotate Screen control to fully counterclockwise. Rotate Red
and Blue Bias controls fully counterclockwise. Slowly rotate
Green Bias control clockwise to produce Green raster.
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3. Loosen the screw holding the Deflection Yoke and remove
the 3 Rubber Wedges, and slide the Deflection Yoke fully
frontward.
4. Rotate and spread the Tabs of the two Purity Magnets to
center the vertical green belt in the picture
screen. The Purity
Magnets are also adjusted to obtain vertical centering of the
raster.
5. SIOWIY slide the Deflection Yoke backward until a uniform
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green screen is obtained.
6. Check the purity of the red and blue screens for uniformity,
turn off other colours to check this (use bias controls).
Readjust the yoke position if necessary until all screens are
pure.
7. Adjust each Bias control and screen control to obtain white
raster. Refer to Gray Scale Adjustment. If part of the picture
screen is coloured, adjust
the Deflection Yoke position
.
forward or backward slightly.
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Figure- 1. PURITY
AND CONVERGENCE MAGNETS
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Adjust tabs angle to superimpose
blue and red vertical line
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Adjust tabs together to
+"
"D\___ p__~ / ;;;;%z%$l%d
BLUE
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Figure-2 BLUE AND RED LINE MOVEMENT
8. Tighten the mounting screw of the Deflection Yoke. Adjust
Convergence next.
CENTER CONVERGENCE ADJUSTMENT
1. Use a dot crosshatch pattern signal.
2. Turn Red and Blue guns on and turn off Green
gun. Adjust
the angle between the Tabs of the Four Pole Magnet 1 and
2,and superimpose the Red and Blue
vertical lines in the
center area of the picture screen. Refer to figure 2.
3. Keeping the mutual angle of the Tabs of the Four Pole
Magnet turn them together to superimpose the Blue and Red
horizontal lines in the center area of the picture screen. Refer
to figure 2.
4. Turn Green gun on and adjust Six Pole Magnet 3 and 4 s that
the Green line superimposed on the Red/Blue lines,
This is the same procedure used in steps 2 and 3.
Refer to figure 3.
OUTER AREA CONVERGENCE ADJUSTMENT
Slightly loosen the screw holding the Deflection Yoke. Adjust
the Deflection Yoke to converge the detail in the outer area (left
side and right side) of the picture screen by orbital movement of
the front of the Yoke, then secure the Deflection Yoke in
appropriate position by putting the wedges as illustrated.
Tighten screw holding the Deflection Yoke.
DEFLECTION YOKE
ION
YOKE
G SCREW
Figure- 4. ADJUSTMENT DEFLECTION
YOKE
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Adjust tabs angle to superimpose
red/blue and green vertical line
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Adjust tabs together to
+
GREEN
\___ r' -4.
/
superimpose red/blue
and green horizontal line
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BLUE/RED
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Figure- 3 BLUE/RED AND GREEN LINE MOVEMENT
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