TCL LCD20VS User manual

20’’ LCD TV TCL LCD20VS
1
Service
Service
Service
Horizontal Frequency
31.5- 49 kHz
TABLE OF CONTENTS
Description Page Description Page
SAFETY NOTICE
ANY PERSON ATTEMPTING TO SERVICE THIS CHASSIS MUST FAMILIARIZE HIMSELF WITH THE
CHASSIS AND BE AWARE OF THE NECESSARY SAFETY PRECAUTIONS TO BE USED WHEN SERVICING
ELECTRONIC EQUIPMENT CONTAINING HIGH VOLTAGES.
CAUTION: USE A SEPARATE ISOLATION TRANSFOMER FOR THIS UNIT WHEN SERVICING
R FOR TH
UNIT WHEN S
6.1.Main Board…………………….……… .......25
6.2.Power Board…………………….……….......27
6.3.Tuner Board…………………….……….......30
6.4.Key Board……………………………….……….......30
6.5.IR Board………………………………………….......30
6.6.Earphone Board………………………..……….......31
7. Block Diagram.…….........................................32
8. Schematic……………...…………..………………...33
8.1 Main Board…………………….…………….….......33
8.2.Power Board…………………….………….......46
8.3 Tuner Board……..…………………….……….......49
9. Exploded View………….………………....….......52
10. BOM List……………….…………………………….53
Table Of Contents.......……..............................…........1
Important Safety Notice.......................................……......2
Revision List.…........................................……...... 3
1. General Specification..............................………........4
2. Operating Instructions…………………….……….......5
2.1. The Use Of Remote Control…….………….…….......5
2.2. To Use the Menu…...…………………….……….......6
2.3. How to Connect…….…………………….………......11
2.4. Front Panel Control Knobs……………….……….....13
3. Input/Output Specification…………....................…....14
4. Mechanical Instructions…………………….................16
5. Repair Flow Chart ……………………….…….…….....19
6. PCB Layout ……….………….………………....….......25

20’’ LCD TV TCL LCD20VS
2
Important Safety Notice
Proper service and repair is important to the safe, reliable operation of all TCL Company Equipment. The service
procedures recommended by TCL and described in this service manual are effective methods of performing service
operations. Some of these service operations require the use of tools specially designed for the purpose. The
special tools should be used when and as recommended.
It is important to note that this manual contains various CAUTIONS and NOTICES which should be carefully read in
order to minimize the risk of personal injury to service personnel. The possibility exists that improper service
methods may damage the equipment. It is also important to understand that these CAUTIONS and NOTICES ARE
NOT EXHAUSTIVE. AOC could not possibly know, evaluate and advise the service trade of all conceivable ways in
which service might be done or of the possible hazardous consequences of each way. Consequently, TCL has not
undertaken any such broad evaluation. Accordingly, a servicer who uses a service procedure or tool which is not
recommended by TCL must first satisfy himself thoroughly that neither his safety nor the safe operation of the
equipment will be jeopardized by the service method selected.
Hereafter throughout this manual, TCL Company will be referred to as TCL.
WARNING
Use of substitute replacement parts, which do not have the same, specified safety characteristics might create
shock, fire, or other hazards.
Under no circumstances should the original design be modified or altered without written permission from TCL. TCL
assumes no liability, express or implied, arising out of any unauthorized modification of design.
Servicer assumes all liability.
FOR PRODUCTS CONTAINING LASER:
DANGER-Invisible laser radiations when openAVOID DIRECT EXPOSURE TO BEAM.
CAUTION-Use of controls or adjustments or performance of procedures other than those specified herein may
result in hazardous radiation exposure.
CAUTION -The use of optical instruments with this product will increase eye hazard.
TO ENSURE THE CONTINUED RELIABILITY OF THIS PRODUCT, USE ONLY ORIGINAL MANUFACTURER'S
REPLACEMENT PARTS, WHICH ARE LISTED WITH THEIR PART NUMBERS IN THE PARTS LIST SECTION OF
THIS SERVICE MANUAL.
Take care during handling the LCD module with backlight unit
-Must mount the module using mounting holes arranged in four corners.
-Do not press on the panel, edge of the frame strongly or electric shock as this will result in damage to the screen.
-Do not scratch or press on the panel with any sharp objects, such as pencil or pen as this may result in damage to
the panel.
-Protect the module from the ESD as it may damage the electronic circuit (C-MOS).
-Make certain that treatment person’s body is grounded through wristband.
-Do not leave the module in high temperature and in areas of high humidity for a long time.
-Avoid contact with water as it may a short circuit within the module.
-If the surface of panel becomes dirty, please wipe it off with a soft material. (Cleaning with a dirty or rough cloth may
damage the panel.)

20’’ LCD TV TCL LCD20VS
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Revision List
Version
Release Date
Revision Instructions
TPV Model
A00
Feb.-28-2007
Initial Release
E206CHHLD1TSNP

20’’ LCD TV TCL LCD20VS
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1. General Specifications
Items
Specification
LCD Panel
Panel Type
20” CPT VA07panel
Driving system
TFT-LCD Panel
Aspect Ratio
4: 3
Resolutions
640 x 480(VGA)
Active Area
408mm (H) x 306mm (V)
Pixel Pitch
0.6375 (H) x 0.6375(V)
Contrast Ratio
400:1 (type)
Brightness
350:1 (type)
Response Time
12ms
ViewAngle
160(H)/160(V) (CR>20)
Display colors
16.2 million
Lamp Type/Life
60000 hr (type)
Color Temperature
Cool / Warm/normal
VGA Function
Input support definition
Only support:640*480 60Hz
If input signal isn’t 640*480 60Hz,Picture display
abnormally, At same time TV set will display” out
of range”，So please return to 640*480 60Hz
Audio input
Mini jack for stereo headphones (3.5ø)
TV Function
TV Standard
PAL B/G, I, D/K, I、NTSC/M
Sound System
NICAM、FM-MONO
Color systems
PAL / NTSC
Video Inputs
AV
RCA x 1
Audio L/R x 1
S-Video
S-Video x 1
Audio L/R x 1
COMPONENT
Y,Cb,Cr x 1
Audio channel L / Rx 1
YPbPr support timing
480i、576i、480p、576p、720p、1080i (include
YCbCr input) Audio L/R x 1
Audio Output
Audio Output: L / R
Speaker (built-in): Two 5W speakers
Headphone Mini-jack for stereo (3.5ø)
Wall Mount
VESA 100 x 100 mm
Power
Power Supply
AC100V~240V, 50/60Hz
Power Consumption
<70W
Environment
Operating
+ 0 °C ~ + 40 °C
Storage
- 10 °C ~ + 50 °C
Operating
10% ~ 85%
Dimension
W x H x D
498 x 498x 181(mm)
Net Weight (Kg)
9.7 Kg
Accessories
Remote Controller, Batteries (x2),AC Power Cord, D-sub Signal Cable,Audio Cable,
User’s Manual,

20’’ LCD TV TCL LCD20VS
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2. Operating Instructions
2.1. The Use of Remote Control
POWER
Press to turn on/off the
TV. The TV is never
completely powered off
unless it is physically
unplugged.
CH
Press or (or ▲ or ▼
button) to brows through
the TV channels which are
not erased.
VOL
Press + or –to adjust the
volume.
0~9/100 Digit buttons
To select a TV channel.
SOUND
It can select TV sound
system, Eg:Mono、Stereo、
Sound I、Sound II
SLEEP
With this key you can set a
time period after which the
TV should switch itself to
standby. Press the key
repeatedly to select the
number of minutes. The
counter runs from
5,10,15,20,25…120
minutes.
MUTE
Temporarily interrupt the
sound or restore it.
DISPLAY
(1) Display Channel
number when use
RF input.
(2) Display input source
when use other input
except TV RF input。
(3) The information will
disappear after 5s。
PRE-CH
To display the previously
selected TV channel.
MENU
Press repeatedly to
display OSD menu or
exit OSD menu.
TV/VIDEO
Select your input source:
press repeatedly to
select TV, AV, S-VIDEO,
YPbPr, PC.
PC
Press this button to turn
PC mode

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MAIN MENU
2.2 To Use the Menus
1. Press the MENU button repeatedly to display each menu.
2. Use the cursor up/down to select a menu item or adjust the setting of Menu item.
3. Use the cursor left/right to enter a submenu or enable/disable the function.
4. Press the MENU button to exit the menu.
Press the MENU button to enter the main OSD (On Screen Display). Adjust the items including Sound setup, Picture
Setup, Function Setup and TV setup. When the input source is PC or YPbPr, AV, S-VIDEO mode, only the Sound
Setup, Picture Setup and Function Setup can be selected; shown in the figure below:
When the input source is TV mode, the Sound Setup, Picture Setup, Function Setup, TV Setup can be selected;
shown in the figure below

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Sound Setup (Same as in all modes)
1. The range of adjusting volume, bass and treble is from 0~100.
2. Select “ON” or “OFF”in Audio selection to control the sound output.
3. The range of adjusting Balance is -50~+50; when adjusting from 0 to -50, the sound from the right track fades
until silence; when adjusting from 0 to +50, the sound from the left track fades until silence.
4. AVL: you can set it “ON” or “OFF”.
The function is to adjust the input sound automatically. You may enable this function when you notice that the
sound in the two tracks are very different, in order to prevent the bad sound effect resulting from large sound
variation.
5. Select "ON" or "OFF" for Loudness: a default setting is preset, you may adjust when necessary.
The following menu will appear when selecting continuously:
6. Preset: Designed for different types of sound output, wherein, the Voice, music and theater modes are preset;
you can set Bass, Treble and Equalizer in sound output mode according to your preference.
7. Equalizer: You can select and adjust 100, 300, 1K, 3K and 8K respectively (the figures represent the sound
frequency range).
8. Reset to default: Reset the sound setting to the factory default value.
Picture Setting
When the input source is in PC mode, shown in the figure below:

20’’ LCD TV TCL LCD20VS
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1. Brightness and Contrast: The range can be adjusted from 0~100.
2. Position: There are two options, Horizontal and Vertical, which can be adjusted from -50 to +50.
3. Video noise: There are two options, Phase and Clock, which can be adjusted from -50 to +50.
4. Sharpness: Select from six options of Softest, Soft, Normal, Auto, Sharp and Sharpest. You may adjust the
above options according to your preference.
5. Auto Adjust: Automatically adjust PC input to the optimal screen size.
6. Info: Prompt the current size for PC input definition (only the definition that can be shown by this device).
7. Colour Temp.: There are four options of colour temperature provided for users - cold, normal, warm and
Personal. You can select the three colour temperatures of cold, normal and warm, or manually adjust red, green or
blue in the personal setting (you can only adjust red, green and blue in the personal setting).
8. Reset to default: It is used to reset the picture settings to the factory default mode.
When the input source is in TV/AV/S-Video mode, shown in the figure below:
1. Brightness and Contrast: The range can be adjusted from 0~100; use Brightness and Contrast options to adjust
the brightness and Contrast of picture.
2. Colour: The range can be adjusted from 0~100; use this option to adjust the colour saturation of picture.
3. Sharpness: Select from five options of Softest, Soft, Normal, Auto, Sharp and Sharpest. You can adjust the
sharpness of picture using any optiois n above.
4. Tint: The range can be adjusted from -50~+50; use thoption to adjust the colour tone of picture(you can only
adjust tint in the NTSC source mode).
5. Dyn. Skin tone: When the Dynamic skin tone is ON, the skin tone of person in the picture becomes more vivid.
6. Colour Temp.: There are three options of colour temperature provided for users - warm, normal and cool.
7. Reset: It is used to reset the picture settings to the factory default mode.
When the input source is in Y Pb/Cb Pr/Cr mode, shown in the figure below:

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Function Setup
1. Language setting: There are three language options provided - English, Simple Chinese and Traditional
Chinese.
2. Sleep timer：Set the time when TV set enter power saving mode。
When sleep timer only remain 1 minute，It will display the counter beginning 59 （it means 59 seconds）and
decrease after per second，Now If you press any key on the remote control, The sleep timer will be set to off。
3. Reset: It is used to reset the OSD settings.
TV Setting
The following menu appears only in the TV mode.

20’’ LCD TV TCL LCD20VS
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1. Channel nr: Shows the current channel number.
2. Colour system: Display the current channel signal color system(after auto search it will be set to auto)
3. Sound system: Display the current channel signal sound system(after auto search it will be set to auto)
4. Auto search :it is used to auto search and store the channel program.
5. Frequency：Display current channel signal frequency, You can fine tune frequency to your favor .
6. AFC can be set to ON or OFF. When it is set to ON, theTV will search the TV signal automatically; when there is
any offset in the signal, it will automatically adjust the channel to the correct position.
7. Skip can be set to ON or OFF. When it is set to ON, a channel can be skipped by pressing the CH button on the
remote control or on the front panel.
8. Reset to default: Reset to the factory default value.

20’’ LCD TV TCL LCD20VS
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2.3 How to Connect
Remove the back plate at the back of the TV as shown on the illustration opposite. Lay the LCD TV with the screen
down on a table, as it will be easier to connect your peripheral equipment. Please take precaution not to damage the
screen
1: VGA input .
2: VGA audio input .
3: AC power input terminal
4: Headphone out put
5: AV signal input
6: Left video/audio track input
7: Right video/audio track input
8: S-Video signal input
9, 10 and 11: Y、Pb/Cb、Pr/Cr Component signal input
12: Y Pb Pr left audio track input
13: Y Pb Pr right audio track input
14: TV signal input
15: AC main switch
VIDEO RECORDER
How to connect
1. Connect the supplied antenna cable to the RF IN port of your VCR.
2. Connect another RF cable from the port of your VCR to the antenna port of you TV set. If you have connected
the video/audio cable to the video AV port, you may have better sound and picture when playing the VCR .
If your VCR has an S-VHS video jack:
For improved picture quality, connect an S-Video cable with the S-VIDEO input on the TV.
S-Video does not provide audio, audio cables must still be connected to provide sound(AV and S terminal share one
audio input).

20’’ LCD TV TCL LCD20VS
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Watching VCR
1. If you use connection TV, select the TV channel auto search.
2. If you use connection AV, select video AV input.
3. Insert videotape in the VCR and press the PLAY button.
CAMERA CAMCORDER VIDEO GAME SET…
How to connect
1. Connect the camera, camcorder and game set to the ports of the audio/video set.
2. The camcorder may get better picture by connecting a S-VHS cable between the S terminal and the Audio set.
How to use it
1. Select the videoAV or S terminal input.
2. Enable the exterior AV equipment.
Warning: In case you notice scrolling images, wrong colors or no color, no picture or even combinations of these, on
your screen, check if the connections are done in the right way. Check if the cable colors match with the Input
connector colors.
DVD PLAYER
How to connect
1. Connect 3 separate components signal cables to the Y, Pb/Cb Pr/Cr ports of the back cover of the DVD player,
and the other ports to the Y, Pb/Cb Pr/Cr ports of the component signal of theTV set.
2. Connect the audio cable to the audio output port of the DVD player and the audio input port of the component
signal of the TV set.
How to use
1. Select COMPONENT.
2. Turn on the DVD set.
DIGITAL SET TOP BOX
Connect the top box to the input port of the component signal.
How to connect
1. Connect 3 separate component signal cables to the Y, Pb and Pr ports of the component signal of the Digital TV/
Top Box, and the Y, Pb and Pr ports of the component signal of theTV set.
2. Connect the audio cable with the audio port of the Digital TV/Top Box and the audio port of the TV set.
How to use
1. Select COMPONENT.
2. Turn on the set-Top box set.
Warning: In case you notice scrolling images, wrong colors or no color, no picture or even combinations of these,
on your screen, check if the connections are done in the right way. Check if the cable colors match with the Input
connector colors.

20’’ LCD TV TCL LCD20VS
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HEADPHONE
1. The headphone jack is located at the rear corner of the TV.
2. The MUTE key on the remote control works on both internal speaker and the headphone.
3. Use volume key to adjust the volume
2.4 Front Panel Control Knobs
①SOURCE: Press to select your input source.
②③VOL: Press to confirm your function selection and adjustment volume.
④:Press to turn on or off the TV.
⑤⑥CH:Select the intended function by pressing these two Keys, or switch the channels in the TV mode.
⑦MENU: Press to show the OSD menu and exit OSD menu at the TV.

20’’ LCD TV TCL LCD20VS
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3. Input/Output Specification
3.1 TV RF Input
TUNER SIGNAL
Channel Coverage
PAL/NSTC-M
Tuner
Philips UV1356E/AIH-4
AIR
CATV
VHF Low band
49.25~85.25
112.25~152.25
VHF High band
168.25~216.25
160.25~440.25
UHF band
471.25~863.25
448.25~456.25
IF Frequency
Picture carrier
Sound carrier
38.00 MHz
31.5 MHz
Impedance
75 ohm terminated
LEVEL
70dBuV
3.2 AV/S-Video/Component Video Inputs
AV
(Composite Video)
Video system
PAL/NSTC-M
Amplitude
1.0Vpp (including sync)
Impedance
75 ohm terminated
S-Video
Video system
NTSC/PAL/SECAM
Y signal amplitude
1.0Vpp (including sync)
C signal amplitude
0.286Vpp
Impedance
75 ohm terminated
Component Video
(D4)
DTV
480i, 480p, 576i,576p,720p, 1080i
Y signal amplitude
1.0Vpp (including sync)
Pr,(R-Y) / Pb,(B-Y) signal amplitude
0.7Vpp
Impedance
75 ohm terminated
3.3 Compatible Mode Table
Dots × Lines
Vertical
Horizontal
Sync Polarity
Presence
Screen Mode
Frequency
Frequency
Horizontal
Vertical
Horizontal
Vertical
FULL
(Hz)
(KHz)
4:3
640 ×480
59.9
31.5
NEG
NEG
YES
YES
YES

20’’ LCD TV TCL LCD20VS
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3.4 RGB Signal
15 - Pin Color Display Signal Cable
Pin No.
Description
Pin No.
Description
1
Red Video
9
Mandatory +5V Supply for PC Bypass
2
Green Video
10
Sync Ground
3
Blue Video
11
Ground
4
Ground
12
Bi-directional Data (SDA) for PC Bypass
5
Ground
13
H-Sync.
6
Red Video Ground
14
V-Sync.
7
Green Video Ground
15
Data Clock (SCL) for PC Bypass
8
Blue Video Ground
1
6
11
15
5
10

20’’ LCD TV TCL LCD20VS
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4. Mechanical Instructions
1. Remove the four screws to remove the base.
2. Remove the seven screws to remove the back cover.
3. Remove many screws to remove the bezel.

20’’ LCD TV TCL LCD20VS
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4.Remove many screws to remove the shield.
5. Remove the 14 screws to remove the main board, power board and I/O board.
6. Remove the two screws to remove the headphone board.

20’’ LCD TV TCL LCD20VS
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7. Remove the ten screws to remove the main frame.

20”LCD TV TCL LCD20VS
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5. Repair Flow Chart
5.1 No Power (No LED indicator)
Check power cord
and board interface
NG
Plug in power cord and interface
Check F901, BD901
Replace F901 or BD901
Check the circuit
Check IC901 Q901
Replace IC901 or Q901
Check T901
Replace T901
Check D904, D902
Replace D904, D902
Replace Q903, ZD902,
IC903 IC902
Check Q903, ZD902, IC903 IC902
and relative circuit
Check Q906, IC905 and relative circuit
No Power
OK
NG
OK
NG
OK
NG
OK
NG
OK
NG
OK

20”LCD TV TCL LCD20VS
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5.2 No Display (LED indicator green)
Check the source
Reset source
Check LVDS cable
NG
Replace LVDS cable
Check 12V power supply
Return to “1”
Check U406
Replace U406
Check panel
Replace panel
Check main board power supply
Check I2C communication
Repair I2C communication relative circuit
No display
OK
NG
OK
NG
OK
OK
NG
OK
NG
OK
NG