NEC PF-68T31, Руководство по обслуживанию

Страница: 15 / 27

.
15
PURITY / CONVERGENCE 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. (Fig2)
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.
Imput 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
WEDGE
DEFLECTION YOKE
P
4 6
P: PURITY MAGNET
4: 4-POLES
(convergence magnets)
6: 6-POLES
(convergence magnets)
P/C MAGNETS
Fig. 1
PURITY MAGNETS
Long lug
Short lug
Bring the long lug over the short lug
and position them horizontally.
Fig. 2
(FRONT VIEW)
GREEN RASTER
CENTER
Fig. 3