Akira CT-21FD9 Schematic

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CHASSIS: H704V

MODEL:

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CT-21FD9CP

CT-21FD9M

Model No: CT-21FD9CP_21FD9M
Version 1.0

CONTENTS

1. SAFETY INSTRUCTIONS ……………………………………... 4

2. GENERAL INSTRUCTIONS …………………………………… 6

3. SPECIFICATIONS ………………………………………………. 9

4. INSTRUCTION MANUAL ……………………………………….11

5. TROUBLESHOOTING …………………………………………..21

6. BLOCK DIAGRAM ……………………………………………….27

7. THE METHOD OF ADJUSTMENT FOR CHASSIS ………….28

8. IC DESCRIPTION ……………………………………………….. 32

9. EXPLODED VIEW ………………………………………………. 37

10. SCHEMETIC DIAGRAM …………………………………………39

11. PRINTED CIRCUIT BOARD …………………………………… 41

12. REPLACEMENT PARTS LIST …………………………………43

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Model No: CT-21FD9CP_21FD9M
Version 1.0

4

• SAFETY PRECAUTION

WARNING: Service should not be attempted by anyone unfamiliar with the necessary

precaution on this receiver. The following are the necessary precaution to be observed before
servicing.

1. Always discharge the picture tube anode to the CRT conductive coating before
handing the picture tube. The picture tube is highly evacuated and if broken, glass
fragments will be violently expelled. Use shatterproof goggles and keep picture tube
away from the body while handing.

2. When replacing chassis in the cabinet, always be certain that all the protective
devices are put back in place, such as; nonmetallic control knobs, insulating covers,
shields, isolation resistor-capacitor network, etc.

3. Before returning the set to the customer, always perform an AC leakage current

check on the exposed metallic parts of the cabinet, such as antennas, terminals,
screw heads, metal overlays, control shafts etc. To be sure the set is safe to operate
without danger of electrical shock. Plug the AC line cord directly onto an 110/220V
AC outlet. Use an AC voltmeter having 500 ohms per volt or more sensitivity in the
following manner. Connect a 1500 ohm 10-watt resistor, paralleled by a 0.15 µF, AC
type capacitor, between a known good earth ground (water pipe, conduit etc.) and the
exposed metallic parts, one at a time. Measure the AC voltage across the
combination of 1500-ohm resistor and 0.15-µF capacitor. Reverse the AC plug at the
AC outlet and repeat AC voltage measurements for each exposed metallic part.
Voltage measured must not exceed 0.3 volts RMS. This corresponds to 0.2 milliamp.
AC Any value exceeding this limit constitutes a potential shock hazard and must be
corrected immediately.

Model No: CT-21FD9CP_21FD9M
Version 1.0

5

1. SAFETY INSTRUCTIONS

1-1 PRODUCT SAFETY NOTICE

Many electrical and mechanical parts in this chassis have special safety-related
characteristics.
These characteristics are often passed unnoticed by a visual inspection and the protection
afforded by them cannot necessarily be obtained by using replacement components rated for
higher voltage, wattage, etc. Replacement parts which have these special safety
characteristics are Identified in this manual and its,
Supplements: Electrical components having such features are identified by shading on the
schematic diagram and the part list. Before replacing any of these components, read the parts
list in this manual carefully. The use of substitute replacement parts which do not have
same safety characteristics as specified in the parts list may create shock, fire or other
hazards.

1-2 SERVICE NOTES

1. When replacing parts or circuit boards, clamp the lead wires to terminals before
soldering.

2. When replacing a high wattage resistor (metal oxide film resistor in the circuit. board)
keep the resistor min 1 /2inch away from the circuit board.

3. Keep wires away from high voltage or high temperature components.

Model No: CT-21FD9CP_21FD9M
Version 1.0

6

2. GENERAL INSTRUCTIONS

2-1 CONVERGENCE MAGNET ASSEMBLY POSITIONING

Convergence magnet assembly and rubber wedges need mechanical positioning following
figure 2.

2-2 COLOR-PURITY-ADJUSTMENT

NOTE: Before attempting any purity adjustments, the receiver should be operated for at least
15 minutes.

1. Demagnetize the picture tube and cabinet by using a degaussing coil.

2. Turn the CONTRAST and BRIGHTNESS controls to maximum.

3. Adjust RED and BLUE BIA, 5 controls to provide only a green rather.

4. Loosen the clamp screw holding the yoke, and slide the yoke backward to provide
vertical green belt (zone) in the picture screen.

5. Remote the Rubber Wedges.

6. Rotate and spread the tabs of the purity magnet (See figure 3) around the neck of the
picture tube until the green belt is in the center of the screen. At the same time,
center the raster vertically.

7. Move the yoke slowly forward until a uniform green screen is obtained. Tighten the
clamp screw of the yoke temporarily.

8. Check the purity of the red and blue raster by adjusting the BIAS controls.

9. Obtain a white raster, referring to “CRT GRAY SCALE ADJUSTMENT”.

10. Proceed with convergence adjustment.

Model No: CT-21FD9CP_21FD9M
Version 1.0

7

2-3 CONVERGENCE ADJUSTMENTS

NOTE: Before attempting any convergence adjustment, the receiver should be operated for at
least 15 minutes.

2-3-1 CENTER CONVERGENCE ADJUSTMENTS

1. Receive a crosshatch pattern with a color bar signal generator.

2. Adjust the BRIGHTNESS and CONTRAST controls for a well-defined pattern.

3. Adjust two tabs of the 4-pole Magnets to change the angle between them (See figure
(3) and superimpose red and blue vertical lines in the center area of the picture
screen.

4. Turn both tabs at the same time keep in their angles constant to superimpose red and
blue horizontal lines at the center of the screen. (See figure 4).

5. Adjust two tabs of 6-Pole Magnets to superimpose red/blue line with green one.
Adjusting the angle affects the vertical lines and rotating both magnets affects the
horizontal lines.

6. Repeat adjustment 3, 4, 5 Keeping in mind red. green and blue movement, because

4-Pole Magnets and 6-Pole Magnets interact and make dot movement complex.

Model No: CT-21FD9CP_21FD9M
Version 1.0

2-3-2 CONVERGENCE ADJUSTMENTS

NOTE: This adjustment requires Rubber Wedge Kit.

1. Loosen the clamping screw of deflection yoke to allow the yoke to tiIt.

2. Place a wedge as shown in figure (2) temporarily.
(Do not remove cover paper on adhesive part of the wedge.)

3. Tilt the front of the deflection yoke up or down to obtain better convergence in
circumference (See figure 4) Push the mounted wedge into the space between
picture tube arid the yoke to hold the yoke temporarily.

4. Place other wedge into bottom space arid remove the cover paper to stick.

5. Tilt the front of the yoke right or left to obtain better convergence in circumference

(See figure 4.)

6. Hold the yoke position arid put another wedge in upper space, remove cover paper
and stick the wedges, recheck overall convergence.

7. Detach the temporarily mounted wedge and put it in another upper space.
Stick 2 on picture tube to fix the yoke.

8. After placing three wedges, recheck overall convergence.
Tighten the screw firmly to hold the yoke tightly in place.

9. Stick 3 adhesive tapes on wedges as shown in figure 2.

Model No: CT-21FD9CP_21FD9M
Version 1.0

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3. SPECIFICATIONS

9

Model No: CT-21FD9CP_21FD9M
Version 1.0

10

Model No: CT-21FD9CP_21FD9M
Version 1.0

4. INSTRUCTION MANUAL

To get the best satisfaction with your new COLOR TV SET, please read carefully and follow the
instruction in this guide.
We recommend that you read it before turning on your TV for the first time.

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4-1. VHF ANTENNA or CABLE HOOK UP

At first, insert the lead of rod antenna into antenna adapter.
And connect antenna adapter to tuner jack. This antenna will provide an excellent picture in most areas.
For the best picture quality, adjust the length and position of antenna.

Model No: CT-21FD9CP_21FD9M
Version 1.0

• MAKE REFERENCE TO THE BELOW THE PICTURE

4-2. TO TURN ON/OFF THE TV SET

4-2-1 To turn on the TV, press MAIN POWER BUTTON on the front of TV, then
press any BUTTON on the PANEL or REMOTE CONTROLLER.

4-2-2 To turn off the TV, press POWER BUTTON on the PANEL or REMOTE
CONTROLLER.

4-3. TO SELECT CHANNEL

You can select the channels with CHANNEL NUMBER buttons or CHANNEL
UP/DOWN button.

4-3-1. TO SELECT CHANNEL DIRECTLY
Press the channel number you want with the number buttons. You can select 0~99 channels.

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Model No: CT-21FD9CP_21FD9M
Version 1.0

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4-3-2. TO SCAN THROUGH CHANNELS
Press the CH UP/DOWN buttons on the PANEL or REMOTE CONTROLLER to find the channel you
want to see.

4-4. TO ADJUST VOLUME

To increase or decrease the volume, press the VOLUME UP/DOWN buttons on the PANEL or
REMOTE CONTROLLER.

4-5 OTHER FUNCTIONS

4-5-1 QUICK VIEW FUNCTION
If you want to go back to the previously viewed channel, press the QUICK VIEW
button.

4-5-2 SLEEP FUNCTION
Press the SLEEP button to set the timer from 30 to 120 minutes. Each time you
press the SLEEP button, changes of time as follows:

Model No: CT-21FD9CP_21FD9M
Version 1.0

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Your TV will be turned off automatically after the set time.
The initial state of SLEEP mode is “ 00”, and the SLEEP FUNCTION does not operate in this state.

4-5-3 MUTE FUNCTION
MUTE button makes the sound off and displays an icon on the right top of the
screen. Press the MUTE button again or press the VOL UP/DOWN buttons to
restore the sound.

4-5-4 TV/AV BUTTON FUNCTION
You can select TV and VIDEO mode.
To select VIDEO mode, press TV/AV button. The icon below will appear on
the right top of screen.

* STEREO MODEL (OPTION)
You can select TV, VIDEO 1 and VIDEO 2 mode.
To select VIDEO 1 mode, press TV/AV button once, and press twice for Video 2 mode. The icon
below will appear on the right top of the screen.

4-5-5 FUZZY FUNCTION
Users can select a combination of picture control. That includes a
combination of contrast, brightness, sharpness, color and tint.
These combinations are classified as three steps, Normal 1, Normal 2,
Favourite.
Each step will be selected by pressing FUZZY button on REMOTE
CONTROLLER.

4-5-6 DISPLAY FUNCTION
Press the DISPLAY button to see the current time and channel on the screen.
It lasts for four seconds. However, you can press again the DISPLAY button
to make the display disappear instantly.
Time display of this mode indicates the state of clock memory of TIMER of
MENU FUNCTION.

Model No: CT-21FD9CP_21FD9M
Version 1.0

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4-5-7. Timer FUNCTION
You can see the current time.

4-5-8. SOUND FUNCTION (STEREO MODEL ONLY)
You can select MONO, STEREO and DUAL 1, DUAL 2 by press the SOUND
button.

4-5-9. OK/DG BUTTON (DC POWER INPUT MODEL ONLY)
DC POWER INPUT MODEL BELOW FUNCTION ITEM ADD.
When the blue parts appear, you can clear the blue parts by press the OK key, but
you can press the OK button just one time during the one minute.

4-6 MENU FUNCTION

If you press the MENU button, six items will
appear on the screen as following.
Press again the MENU button. Then the display
will return to the original screen.

4-6-1. PICTURE

1) Press Menu

2) Press CH UP/DOWN to select PICTURE item, and press O.K

3) Then, four items will appear as following on the screen.

4) Press CH UP/DOWN to select the item you want to adjust.

5) And press VOL UP/DOWN to adjust the item’s value.

6) To adjust other items, repeat step 4 and 5.

7) Press MENU to return to the MENU screen.

Model No: CT-21FD9CP_21FD9M
Version 1.0

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• TINT item appears only when TV set receives the NTSC (play back only) signal.

4-6-2. SOUND (STEREO MODEL ONLY)

1) Press Menu

2) Press CH UP/DOWN to select SOUND item, and press O.K

3) Then, seven items appear as following on the screen.

4) Press CH UP/DOWN to select the item you want to adjust.

5) And press VOL UP/DOWN to adjust the item’s value.

6) To adjust other items, repeat steps 4 and 5.

7) Press MENU to return to the MENU screen.

• AVC : Press VOL. UP/DOWN, then OSD changes from OFF to ON.

You can hear different sound of many broadcasting stations as regular valued sound through this
function.

• Equalizer: Higher resolution is possible in a gain step of about

1/8 dB. With positive equalizer settings, internal clipping may
occur even with overall volume less than 0 dB. This will lead
to a clipped output signal. Therefore, it is not recommended to
set equalizer bands to a value that, in conjunction with volume,
would result in an overall positive gain.

• Audio in (Sound L, R divide mode): When you use the audio

out, you selected STEREO or MONO mode STEREO mode:

audio out divided L, R

• MONO mode: Audio out L (You must hear sound L)

Model No: CT-21FD9CP_21FD9M
Version 1.0