SECTION 3 SET-UP ADJUSTMENTS

When complete readjustment is necessary or a new picture tube is installed, carry out the following adjustments.

Unless there are specific instructions to the contrary, carry out these adjustments with the rated power supply.

Unless there are specific instructions to the contrary, set the controls and switches to the following settings :

Contrast

80% [or remote control normal]

Brightness

50%

Carry out the adjustments in the following order :

3-1. Beam Landing.

3-2. Convergence.

3-3. Focus.

3-4. White Balance.

Note : Test equipment required.

1.Color bar/pattern generator.

2.Degausser.

3.Oscilloscope.

4.Digital multimeter.

Preparation:

1.In order to reduce the influence of geomagnetism on the set’s picture tube, face it in an easterly or westerly direction.

2.Switch on the set’s power and degauss with the degausser.

3-1. Beam Landing

1.Input an all white signal from the pattern generator. Set the Contrast and Brightness to normal.

2.Set the pattern generator raster signal to Red.

3.Move the deflection yoke forward and adjust with the purity control so that the Red is at the centre and the Blue and Green take up equally sized areas on each side of the screen. [See Fig.3-1 - 3-3].

4.Move the deflection yoke backwards and adjust so that the entire screen becomes Red. [See Fig.3-1]

5.Switch the raster signal to Blue, then to Green and verify the condition.

6.When the position of the deflection yoke has been determined, fasten the deflection yoke with the screws.

7.If the beam does not land correctly in all the corners, use a magnet to correct it. [See Fig.3-4]

Fig. 3-2.

Purity

Fig. 3-3.

GREEN

RED

BLUE

Fig. 3-1.

Purity control corrects this area

ab

cd

Deflection yoke positioning corrects these areas

Disk magnets or rotatable disk magnets correct these areas (a-d)

Caution :

 

High voltages are present on the Deflection yoke terminals

 

- take care when handling the Deflection yoke whilst carrying

 

out adjustments.

Disk Magnets

 

 

Fig.3-4

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Sony KV-29LS30E service manual SET-UP Adjustments