TOSHIBA 28Z23G
Service Manual

CONVERGENCE ADJUSTMENTS NOTE: Before attempting any convergence adjustments, the receiver should be operated for at least fifteen minutes. s CENTER CONVERGENCE ADJUSTMENT 1. Use the cross-dot pattern from among the built-in test signals. 2. Set the brightness and contrast for well defined pattern. 3. Adjust two tabs of the 4-Pole Magnets to change the angle 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 horizontal 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.
6-POLE MAGNETS 4-POLE MAGNETS

s CIRCUMFERENCE CONVERGENCE ADJUSTMENT 1. Loosen the clamping screw of deflection yoke slightly to allow the yoke to tilt. 2. Temporarily put a wedge as shown in figure 1. (Do not remove cover paper on adhesive part of the wedge.) 3. 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. 4. Put other wedge into bottom space and remove the cover paper to stick. 5. Tilt front of the yoke right or left to obtain better convergence in circumference. (See figure 3.) 6. 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. 7. Detach the temporarily mounted wedge and put it in another upper space. Stick it on picture tube to fix the yoke. 8. After fixing three wedges, recheck overall convergence. Tighten the screw firmly to fix the yoke and check the yoke is firm. 9. Stick three adhesive tapes on wedges as shown in figure 1.

ADJUST THE ANGLE (VERTICAL LINES)

FIXED

ROTATE TWO TABS AT THE SAME TIME (HORIZONTAL LINES) PURITY MAGNETS CONVERGENCE MAGNET ASSEMBLY ADJUSTMENT OF MAGNETS

Figure 2.
BLU RED RED/BLU GRN

BLU RED

RED/BLU GRN

4-POLE MAGNETS MOVEMENT

6-POLE MAGNETS MOVEMENT

Center Convergence by Convergence Magnets

BGR R G B RGB INCLINE THE YOKE UP (OR DOWN) B G R

B G R

RGB

BGR

R G B

INCLINE THE YOKE RIGHT (OR LEFT)

Circumference Convergence by DEF Yoke

Figure 3. Dot Movement Pattern

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SPECIFIC INFORMATIONS GENERAL ADJUSTMENTS