Saturday, November 24, 2012

AKIRA CT-21CQS5CPT _ SERVICE MODE _ COLOR PURITY ADJUSTMENT_ CONVERGENCE ADJUSTMENTS




SERVICE MODE

  1. Set the volume to 0. [Zero]
  2. Then press and hold the MUTE button on the remote control, and press the MENU button on the TV to enter the SERVICE mode.
  3.  To Exit from the SERVICE mode, turn off the TV set by the POWER button on the remote control.



 THE BELOW STATED PROCEEDINGS ARE COMMON TO ALL PICTURE TUBE BASED TVs

 COLOR PURITY ADJUSTMENT

 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 raster meet the requirement.

CONVERGENCE ADJUSTMENT

CENTER CONVERGENCE ADJUSTMENT
  1. Adjust the brightness/contrast controls to obtain a sharp picture.
  2. Adjust two tabs of the 4-pole magnet to change the angle between them and red and blue vertical lines are superimposed each other on the center of the screen.
  3. Turn both tabs at the same time keeping the angle constant to superimpose red and blue horizontal on the center of the screen.
  4. Adjust two tabs of the 6-pole magnet to superimpose red/blue line and green line.
  5. Remember red and blue movement. Repeat steps 2.1.3 2. 1.5 until optimal convergence is obtained.
CIRCUMFERENCE CONVERGENCE ADJUSTMENT

  • Loosen the clamp screw holding the deflection yoke assembly and allow it tilting.
  • Temporarily put the first wedge between the picture tube and deflection yoke assembly.  Move front of the deflection yoke up or down to obtain better convergence in circumference.  Push the mounted wedge in to fix the yoke temporarily.
  • Put the second wedge into bottom.
  • Move front of the deflection yoke to the left or right to obtain better convergence in circumference.
  • Fix the deflection yoke position and put the third wedge in either upper space. Fasten the deflection yoke assembly on the picture tube.
  • Detach the temporarily mounted wedge and put it in either upper space. Fasten the deflection yoke assembly on the picture tube.
  • After fastening the three wedges, recheck overall convergence and ensure to get optimal convergence. Tighten the lamp screw holding the deflection yoke assembly.






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