JVC AV20NT11/P
Service Manual

4.7.8 PURITY AND CONVERGENCE PURITY ADJUSTMENT (1) Demagnetize CRT with the demagnetizer.
WEDGE DEFLECTION YOKE
P

(2) Loosen the retainer screw of the deflection yoke.

(3) Remove the wedges.

CRT
46

(4) Input a green raster signal from the signal generator, and turn the screen to green raster.

P/C MAGNETS

(5) Move the deflection yoke backward.
P/C MAGNETS P : PURITY MAGNET 4 : 4 POLES (convergence magnets) 6 : 6 POLES (convergence magnets)

(6) Bring the long lug of the purity magnets on the short lug and position them horizontally. (Fig.2)

Fig.1 (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 deflection yoke so that the whole screen will become green.
Long lug

PURITY MAGNETS

(9) Insert the wedge to the top side of the deflection yoke so that it will not move.
Short lug

(10) Input a crosshatch signal.

Bring the long lug over the short lug and position them horizontally.

Fig.2 (11) Verify that the screen is horizontal.

(12) Input red and blue raster signals, and make sure that purity is properly adjusted.
(FRONT VIEW) GREEN RASTER

CENTER

Fig.3

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