Toshiba 3787DB - Page 5

CONVERGENCE ADJUSTMENTS
NOTE: Before attempting any convergence adjustments, the
receiver should be operated for at least fifteen min-
utes.
m@ CENTER CONVERGENCE ADJUSTMENT
. Use the cross-dot pattern from among the built-in test sig-
nals.
. Set the brightness and contrast for well defined pattern.
. Adjust two tabs of the 4-Pole Magnets to change the an-
gle between them (See figure 2.) and superimpose red
and blue vertical lines in the center area of the picture
screen.
4. Turn the both tabs at the same time keeping the angle
constant to superimpose red and blue horizontal lines at
the center of the screen.
5. Adjust two tabs of 6-Pole Magnets to superimpose red/
blue line and green one. Adjusting the angle affects the
vertical lines and rotating both magnets affects the hori-
zontal lines.
6. Repeat adjustments 3, 4, 5 keeping in mind red, green
and blue movement, because 4-Pole Magnets and 6-Pole
Magnets have mutual interaction and make dot movement
complex.
—
[cu e)
4-POLE
MAGNETS
PURITY
MAGNETS
CONVERGENCE MAGNET ASSEMBLY
Figure 2.
BLU RED
4-POLE MAGNETS MOVEMENT
ADJUST THE ANGLE
(VERTICAL LINES)
CIRCUMFERENCE CONVERGENCE ADJUSTMENT
. Loosen the clamping screw of deflection yoke slightly to
allow the yoke to tilt.
. Temporarily put a wedge as shown in figure 1. (Do not
remove cover paper on adhesive part of the wedge.)
. Tilt front of the deflection yoke up or down to obtain better
convergence in circumference. (See figure 3.) Push the
mounted wedge into the space between picture tube and
the yoke to fix the yoke temporarily.
. Put other wedge into bottom space and remove the cover
paper to stick.
. Tilt front of the yoke right or left to obtain better conver-
gence in circumference. (See figure 3.)
. Keep the yoke position and put another wedge in either
upper space. Remove cover paper and stick the wedge
on picture tube to fix the yoke.
. Detach the temporarily mounted wedge and put it in an-
other upper space. Stick it on picture tube to fix the yoke.
. After fixing three wedges, recheck overall convergence.
Tighten the screw firmly to fix the yoke and check the yoke
is firm.
. Stick three adhesive tapes on wedges as shown in figure
1.
ROTATE TWO TABS\\
AT THE SAME TIME
(HORIZONTAL LINES)
ADJUSTMENT OF MAGNETS
RED/BLU GRN
RED/BLU
6-POLE MAGNETS MOVEMENT
Center Convergence by Convergence Magnets
INCLINE THE YOKE UP (OR DOWN)
(INCLINE THE YOKE RIGHT (OR LEFT)
Circumference Convergence by DEF Yoke
Figure 3. Dot Movement Pattern
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