JVC AV20D303/S
Service Manual

AV-20D303

ADJUSTMENT OF PURITY / CONVERGENCE
PURITY ADJUSTMENT
1. Demagnetize CRT with the demagnetizer.
W EDGE DEF LECT ION YOKE
P

2. Loosen the retainer screw of the deflec tion yoke.

3. Remove the wedges.
CR T

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

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5. Move the deflection yoke backward.

P/C MAGNET S

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

# P/C MAGNETS P : PURITY MAGNET 4 : 4 POLES (convergence magnets) 6 : 6 POLES (convergence magnets) Fig.1

7. Adjust the gap between two lugs so that the GREEN RASTER will come into the c enter of the screen. (Fig.3)

8. Move the deflection yoke forward, and fix the pos ition of the deflection yoke so that the whole screen will bec ome green.

9. Ins ert the wedge to the top side of the deflection yoke so that it will not move. 10. Input a cross hatch signal.
Long lug

PURIT Y MAGNET S

11. Verify that the screen is horizontal.
Short lug

12. Input red and blue raster signals, and make sure that purity is properly adjusted.

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

Fig.2

(F RONT VIEW )

GREEN RASTER

CEN TER

Fig.3

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No. 51939