Toshiba 13A20 Service Manual - Page 7

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WARNING: BEFORE SERVICING THIS CHASSIS, READ THE "X-RAY RADIATION PRECAUTION", "SAFETY PRECAU-

TION" AND "PRODUCT SAFETY NOTICE" ON PAGE 3 OF THIS MANUAL.

SET-UP ADJUSTMENT FOR 13", 14", 19", 20".

The following adjustments should be made when a complete realignment is required or a new picture tube is installed.

Perform the adjustments in order as follows :

1. Color Purity

2. Convergence

3. White Balance

Note: The PURITY/CONVERGENCE MAGNET assembly and rubber wedges need mechanical positioning.

Refer to figure 1.

Mounting position of the purity magnet assembly should fit to same position as old one because slightly difference to

the position depend on a kind of tube.

There are no adjustment of purity and convergence in some picture tube (Unified with purity magnet)

COLOR PURITY ADJUSTMENT

NOTE : Before attempting any purity adjustments, the receiver

should be operated for at least fifteen minutes.

1. Demagnetize the picture tube and cabinet using a degauss-

ing coil.

2. Set the brightness and contrast to maximum.

3. Use a green raster from among the built-in test signals.

4. Loosen the clamp screw holding the yoke and slide the

yoke backward or forward to provide vertical green belt

(zone) in the picture screen.

DEFLECTION

YOKE

GLASS CLOTH

TAPES

SET-UP ADJUSTMENT

5. Remove the Rubber Wedges.

6. Rotate and spread the tabs of the purity magnet (See fig-

ure 2.) around the neck of the picture tube until the green

belt is in the center of the screen. At the same time, enter

the raster vertically.

7. Slowly move the yoke forward or backward until a uniform

green screen is obtained. Tighten the clamp screw of the

yoke temporarily.

8. Check the purity of the red and blue raster.

14mm(13", 14")

19mm(19", 20")

PURITY/

CONVERGENCE

MAGNET ASS'Y

Figure 1.

– 4 –

TEMPORARY

MOUNTING

DEFLECTION

YOKE

RUBBER WEDGE

ADHESIVE