Haier DTA-2198 Service Manual page 12

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. (Fig2)
7. Adjust the gap between two lugs so that the GREEN
RASTER will come into the centre 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.
CRT
P: PURITY MAGNET
4: 4-POLES
6: 6-POLES
Fig. 1
PURITY MAGNETS
Long lug
Short lug
Bring the long lug over the short lug and
position them horizontally.
(FRONT VIEW)
12
WEDGE
DEFLECTION YOKE
P
4 6
P/C MAGNETS
(convergence magnets)
(convergence magnets)
Fig. 2
GREEN RASTER
CENTER
Fig. 3