AKIRA CT-21CCS5CPT SERVICE MODE AND ADJUSTMENTS
SERVICE MODE
To enter the SERVICE mode
Set the volume to 0. Then press and hold the MUTE button on the remote control, and press the MENU button on the TV to enter the SERVICE mode.
To exit from the
SERVICE mode, turn off the TV set by the POWER button on the remote control.
Caution: The user service mode
adjustment can be changed only when service personnel
adjust the whole set data during servicing. As the control
data have dramatic effects on functions.and performance of the TV, service personnel should not tell
user how to enter the SERVICE mode to avoid improper data settings.
White Balance Adjustment
Generally, white balance adjustment is made with professional equipment. It’s
not practical to get good white balance only through manual adjustment. For TVs
with I2C bus control, change the bus data to adjust white balance
CIRCUIT ADJUSTMENTS
Preparation:
Circuit adjustments should be made only after completion of set-up adjustments.
Circuit adjustments can be performed using the adjustable components inside the
TV set. For TVs with 2 I C bus control, first change the bus data.
Degaussing
A degaussing coil is built inside the TV set. Each time the TV is powered on,
the degaussing coil will automatically degauss the TV. If the TV is magnetized
by external strong magnetic field, causing color spot on the screen, use a
specific degausser to demagnetize the TV in the following ways. Otherwise,
color distortion will be shown on the screen.
#Power on the TV set and operate it for at least 15 minutes.
#Receive red full-field pattern.
#Power on the specific degausser and face it to the TV screen.
3Turn on the degausser. Slowly move it around the screen and slowly take it
away from the TV
#Repeat the above steps until the TV is degaussed completely. Confirmation and Adjustment for Voltage
Caution: +B voltage has close relation to high voltage. To prevent X-ray
radiation, set +B voltage to the rated value
#Make sure that the supply voltage is within the range of the rated value.
#Connect a digital voltmeter to the voltage output terminal of the main PCB.
Power on the TV and set the brightness and sub-brightness to minimum. Ensure
that the voltage from the main PCB reads as follows.
#Regulate voltage adjustment components on the power section until the +B the
voltage reaches the rated value.
High Voltage Inspection
Measure voltages of test points on the main PCB with the digital voltmeter.
Measure the CRT high voltage with the high-voltage testing equipment and heater
voltage with the high-frequency effective voltmeter.
Focus Adjustment
Caution: Dangerously high voltages are present inside the TV. Extreme caution
should be exercised when working on the TV with the back removed.
#After removing the back cover, look for the FBT on the main PCB. There should
be a FCB (FOCUS) on the FBT.
#Power on the TV and preheat it for 15 min.
#Receive a normal TV signal. Rotate knob of the FCB until you get a sharp
picture.
Convergence Adjustment
Preparation: Before attempting any convergence adjustment, the TV should
be operated for at least 15 minutes.
#Center convergence adjustment.
#Receive dot pattern.
#Adjust the brightness/contrast controls to obtain a sharp picture.
#Adjust two tabs of the 4-pole magnet to change the angle between them and red
and blue ertical lines are superimposed each other on the center of the screen.
#Turn both tabs at the same time keeping the angle constant to superimpose red
and blue horizontal on the center of the screen.
#Adjust two tabs of the 6-pole magnet to superimpose red/blue line and green
line.
#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.
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.
SERVICE MODE
To enter the SERVICE mode
Set the volume to 0. Then press and hold the MUTE button on the remote control, and press the MENU button on the TV to enter the SERVICE mode.
To exit from the
SERVICE mode, turn off the TV set by the POWER button on the remote control.
Caution: The user service mode
adjustment can be changed only when service personnel
adjust the whole set data during servicing. As the control
data have dramatic effects on functions.and performance of the TV, service personnel should not tell
user how to enter the SERVICE mode to avoid improper data settings.
White Balance Adjustment
Generally, white balance adjustment is made with professional equipment. It’s not practical to get good white balance only through manual adjustment. For TVs with I2C bus control, change the bus data to adjust white balance
Generally, white balance adjustment is made with professional equipment. It’s not practical to get good white balance only through manual adjustment. For TVs with I2C bus control, change the bus data to adjust white balance
CIRCUIT ADJUSTMENTS
Preparation:
Circuit adjustments should be made only after completion of set-up adjustments. Circuit adjustments can be performed using the adjustable components inside the TV set. For TVs with 2 I C bus control, first change the bus data.
Preparation:
Circuit adjustments should be made only after completion of set-up adjustments. Circuit adjustments can be performed using the adjustable components inside the TV set. For TVs with 2 I C bus control, first change the bus data.
Degaussing
A degaussing coil is built inside the TV set. Each time the TV is powered on, the degaussing coil will automatically degauss the TV. If the TV is magnetized by external strong magnetic field, causing color spot on the screen, use a specific degausser to demagnetize the TV in the following ways. Otherwise, color distortion will be shown on the screen.
A degaussing coil is built inside the TV set. Each time the TV is powered on, the degaussing coil will automatically degauss the TV. If the TV is magnetized by external strong magnetic field, causing color spot on the screen, use a specific degausser to demagnetize the TV in the following ways. Otherwise, color distortion will be shown on the screen.
#Power on the TV set and operate it for at least 15 minutes.
#Receive red full-field pattern.
#Power on the specific degausser and face it to the TV screen.
3Turn on the degausser. Slowly move it around the screen and slowly take it away from the TV
#Repeat the above steps until the TV is degaussed completely. Confirmation and Adjustment for Voltage
#Receive red full-field pattern.
#Power on the specific degausser and face it to the TV screen.
3Turn on the degausser. Slowly move it around the screen and slowly take it away from the TV
#Repeat the above steps until the TV is degaussed completely. Confirmation and Adjustment for Voltage
Caution: +B voltage has close relation to high voltage. To prevent X-ray
radiation, set +B voltage to the rated value
#Make sure that the supply voltage is within the range of the rated value.
#Connect a digital voltmeter to the voltage output terminal of the main PCB. Power on the TV and set the brightness and sub-brightness to minimum. Ensure that the voltage from the main PCB reads as follows.
#Regulate voltage adjustment components on the power section until the +B the voltage reaches the rated value.
#Make sure that the supply voltage is within the range of the rated value.
#Connect a digital voltmeter to the voltage output terminal of the main PCB. Power on the TV and set the brightness and sub-brightness to minimum. Ensure that the voltage from the main PCB reads as follows.
#Regulate voltage adjustment components on the power section until the +B the voltage reaches the rated value.
High Voltage Inspection
Measure voltages of test points on the main PCB with the digital voltmeter. Measure the CRT high voltage with the high-voltage testing equipment and heater voltage with the high-frequency effective voltmeter.
Measure voltages of test points on the main PCB with the digital voltmeter. Measure the CRT high voltage with the high-voltage testing equipment and heater voltage with the high-frequency effective voltmeter.
Focus Adjustment
Caution: Dangerously high voltages are present inside the TV. Extreme caution should be exercised when working on the TV with the back removed.
#After removing the back cover, look for the FBT on the main PCB. There should be a FCB (FOCUS) on the FBT.
#Power on the TV and preheat it for 15 min.
#Receive a normal TV signal. Rotate knob of the FCB until you get a sharp picture.
Caution: Dangerously high voltages are present inside the TV. Extreme caution should be exercised when working on the TV with the back removed.
#After removing the back cover, look for the FBT on the main PCB. There should be a FCB (FOCUS) on the FBT.
#Power on the TV and preheat it for 15 min.
#Receive a normal TV signal. Rotate knob of the FCB until you get a sharp picture.
Convergence Adjustment
Preparation: Before attempting any convergence adjustment, the TV should be operated for at least 15 minutes.
#Center convergence adjustment.
#Receive dot pattern.
#Adjust the brightness/contrast controls to obtain a sharp picture.
#Adjust two tabs of the 4-pole magnet to change the angle between them and red and blue ertical lines are superimposed each other on the center of the screen.
#Turn both tabs at the same time keeping the angle constant to superimpose red and blue horizontal on the center of the screen.
#Adjust two tabs of the 6-pole magnet to superimpose red/blue line and green line.
#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.
Preparation: Before attempting any convergence adjustment, the TV should be operated for at least 15 minutes.
#Center convergence adjustment.
#Receive dot pattern.
#Adjust the brightness/contrast controls to obtain a sharp picture.
#Adjust two tabs of the 4-pole magnet to change the angle between them and red and blue ertical lines are superimposed each other on the center of the screen.
#Turn both tabs at the same time keeping the angle constant to superimpose red and blue horizontal on the center of the screen.
#Adjust two tabs of the 6-pole magnet to superimpose red/blue line and green line.
#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.
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.
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.
#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.
