Magnum PF21500 Service Manual - page 4
the exterior of the TV set or CRT screen. Do not use liquid cleaners or aerosol cleaners.
2. ADJUSTMENTS
2.1 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:
Color purity
Convergence
White balance
Notes:
The purity/convergence magnet assembly and rubber wedges need mechanical positioning.
For some picture tubes, purity/ convergence adjustments are not required.
2.1.1 Color Purity Adjustment
Preparation:
Before starting this adjustment, adjust the vertical sync, horizontal sync, vertical amplitude and focus.
•Face the TV set north or south.
•Connect the power plug into the wall outlet and turn on the main power switch of the TV set. •Operate the
TV for at least 15 minutes.
•Degauss the TV set using a specific degaussing coil.
•Set the brightness and contrast to maximum.
•Counter clockwise rotate the R /B low brightness potentiometers to the end and rotate the green low brightness
potentiometer to center.
•Receive green raster pattern signals.
•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. •Slowly move the deflection yoke assembly
forward or backward until a uniform green screen is obtained.
•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.
4