Service manual

Model no.:CT-21CBS5CPH.doc

version 1.0

ADJUSTMENTS

SET-UP ADJUSTMENTS

The following adjustments should be made when a complete realignment is required or a new

picture tube is installed.

Perform the adjustments in the following order:

1. Color purity

2. Convergence

3. White balance

Notes:

1. The purity/convergence magnet assembly and rubber wedges need mechanical ositioning.

Refer to Fig1, 2.

2. For some picture tubes, purity/ convergence adjustments are not required.

1. Color Purity Adjustment

Preparation:

Before starting this adjustment, adjust the vertical sync, horizontal sync, vertical amplitude and

focus.

1.1 Face the TV set north or south.

1.2 Connect the power plug into the wall outlet and turn on the main power switch of the TV set.

1.3 Operate the TV for at least 15 minutes.

1.4 Degauss the TV set using a specific degaussing coil.

1.5 Set the brightness and contrast to maximum.

1.6 Counter clockwise rotate the R /B low brightness potentiometers to the end and rotate

the green low brightness potentiometer to center.

1.7 Receive green raster pattern signals.

1.8 Loosen the clamp screw holding the deflection yoke assembly and slide it forward

or backward to display a vertical green zone on the screen. Rotate and spread the

tabs of the purity magnet around the neck of the CRT until the green zone is

located vertically at the center of the screen.

1.9 Slowly move the deflection yoke assembly forward or backward until a uniform

green screen is obtained.

1.10 Tighten the clamp screw of the assembly temporarily. Check purity of the red raster

and blue raster until purities of the three rasters meet the requirement.