JVC AV-T2122 Service Manual page 18

AV-T2122
PURITY, CONVERGENCE
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
deflection 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
properly adjusted.
24
CRT
$ P/C MAGNETS
P : PURITY MAGNET
4 : 4 POLES (convergence magnets)
6 : 6 POLES (convergence magnets)
Long lug
Short lug
Bring the long lug over the short lug
and position them horizontally.
(FRONT VIEW )
No.51866
WEDGE
DEFLECTION
YOKE
P
4 6
P / C
MAGNETS
Fig.1
PURITY MAGNETS
Fig.2
GREEN RASTER
CENTER
Fig.3