JVC AV-21L11, AV-21L31, AV-25L31,, Руководство по обслуживанию

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30 No. 51904
AV-21L11
AV-21L31
AV-25L31
PURITY AND CONVERGENCE ADJUSTMENTS
Note: The final adjustment of CONVERGENCE must be done after the
FOCUS adjustment. (CONVERGENCE is changed by FOCUS
adjustment.)
When makes difference by FOCUS adjustment, should be
reconfirming PURITY adjustment.
PURITY ADJUSTMENT
1. Demagnetize CRT with the demagnetizer.
2. Loosen the retainer screw of the deflection yoke.
3. Remove the wedges.
4. Input a green raster signal from the signal generator, and turn the
screen to green raster.
5. Move the deflection yoke backward.
6. Bring the long lug of the purity magnets on the short lug and position
them horizontally. (Fig. 2)
7. Adjust the gap between two lugs so that the GREEN RASTER will
come into the center of the screen. (Fig. 3)
8. Move the deflection yoke forward, and fix the position of the deflec-
tion yoke so that the whole screen will become green.
9. Insert the wedge to the top side of the deflection yoke so that it will
not move.
10. Input a crosshatch signal.
11. Verify that the screen is horizontal.
12. Input red and blue raster signals, and make sure that purity is prop-
erly adjusted.
Fig. 1
• P/C MAGNETS
P : PURITY MAGNET
4 : 4 POLES (convergence magnets)
6 : 6 POLES (convergence magnets)
CRT
WEDGE
P
P / C
MAGNETS
4 6
DEFLECTION
YOKE
Fig. 2
Long lug
Short lug
PURITY MAGNETS
Bring the long lug over the short lug
and position them horizontally.
Fig. 3
(FRONT VIEW)
GREEN RASTER
CENTER