TCL LCD20W5HE User manual

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Service
Service
Service
TABLEOFCONTENTS
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 VOLTAGE.
Table Of Contents.......……..............................…........1
Revision List.…........................................……......2
Important Safety Notice.……..................……......3
1.General Specifications..............................………........4
2.Operating Instructions………..…………………….......5
2.1.The Use of Remote Control…................……...........5
2.2.To Use the Menu………..............................…...........7
2.3.LCD TV Description…….…..............……...............15
2.4.Interface Connector……............................…...........15
3.Precautions and Notices…............……………............16
3.1.Assembly Precaution…............………….................16
3.2.Operating Precaution…………...........................16
3.3.Storage Precaution…......………………..................16
3.4.High Voltage Warning.…..........…………................16
4.Input/Output Description……..…………… ...........17
4.1.D-SUB Connector……...…………………....….......17
4.2.Factory Preset Display Modes……………..….......18
5.Front Panel Control Knobs…....................................18
6.Repair Flow Chart…….............................................19
7.Mechanical Instructions……………................25
8.PCB Layout..………….......................................29
8.1.Main Board……….....…….................................29
8.2.Power Board…...………...................................32
8.3.Tuner Board…………........................................34
8.4.IR Board……………….......................................35
8.5.Key Board………………......................................35
8.6.Headphone Board………..................................36
9.Block Diagram………………..............................37
10.Schematic Diagram………………...............…38
10.1.Main Board.............................................38
10.2.Power Board....……....................................51
10.3.Tuner Board....……....................................52
11.Exploded View………..….......................................56
12.BOM………………………………………….............57
CAUTION: USE A SEPARATE ISOLATION TRANSFOMER FOR THIS UNIT WHEN SERVICING

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Revision List
Revision Date Revision History TPV Model
A00 Sep-09-06 First Version Release E206MTNMC1TLNP

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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. TCL 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 may 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 radiation when open AVOID 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.)

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1. General Specifications
Items Specification
Screen Size 20” (51cm)
Driving system TFT-LCD Panel (CMO)
Resolution 1366×768
Display Area 444.633(H) x 249.984 (V)
Pixel Pitch 325.5um × 325.5um
Display colors 16.2 million
Contrast Ratio 1000:1 (Typical)
Brightness 500 cd/m2(Typical)
Viewing Angle 176(H)/176(V) (CR>20)
Response Time 8ms
LCD Panel
Lamp Type/Life 60000 hr
TV Standard PAL B/G, D/K, I, L/L’ and SECAM L/L’(Multi-Europe)
Full Channel with Electronic PLL Tuner
Sound Systems NICAM
TV Function
Video Color systems PAL/SECAM/NTSC
Video Inputs SCART, S-Video, Composite, HDMI, Component
Signal Input Analog: D-Sub 15 pin (detachable cable)
PnP compatibility DDC 2B
Input frequency Analog: FH: 31.5KHz to 48KHz FV: 56Hz to 75Hz
PC Input
Input Audio Headphone Mini-jack for stereo (3.5ø)
Speaker (built-in): 3 watt speakers x 2
Headphone Mini-jack for stereo (3.5ø)
Audio Output Audio Output: L / R
Line Output (SCART L/R)
Other Function PIP (in PC Mode)
Table Stand Included
Wall Mount VESA 100 x 100 mm
Power Supply AC100V~240V, 50/60Hz
Power
Power Consumption < 90 W
Operating temp + 0 °C ~ + 40 °C
Storage temp - 10 °C ~ + 50 °C
Environment
Operating humidity 10% ~ 85%

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2. Operating Instructions
2.1. The Use Of Remote Control

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2.2 To Use The Menus

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2.3 LCD TV Description
The LCD TV will contain a main board, a power board, an IR board, a key board, a tuner board and a
headphone Board. The main board and power board will house the flat panel to control logic I²C bus, DDC,
brightness control logic for LCD panel, DC-DC conversion to supply the appropriate power to the whole board
and transmitting TTL level signals into LCD Module to drive the LCD display circuit.
The inverter board will drive the five CCFLs (Cold Cathode Fluorescent Tube).
The switching power board will provides the power ON/OFF to control the TV and control LED indicator for
DPMS.
The function keyboard and Remote Control will provide the OSD control signal to the Main Board.
2.4 Interface Connector
(A) Power Cord Connector.
(B) RF Signal Connector.
(C) Video / Audio Signal Connectors.
(D) PC D-sub 15 pin Connector.
(E) PC Audio Connector
(F) SCART Connector
(G) S-Video Connector
(H) Composite Connector
(I) Component Connector
(J) HDMI Connector

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3. Precautions and Notices
3.1 Assembly Precaution
(1) Please do not press or scratch LCD panel surface with anything hard. And do not soil LCD panel surface
by touching with bare hands (Polarize film, surface of LCD panel is easy to be flawed)
In the LCD panel, the gap between two glass plates is kept perfectly even to maintain display
characteristic and reliability. If this panel is subject to hard pressing, the following occurs:
(a) Uniform color (b) Orientation of liquid crystal becomes disorder
(2) Please wipe out LCD panel surface with absorbent cotton or soft cloth in case of it being soiled.
(3) Please wipe out drops of adhesive like saliva and water in LCD panel surface immediately.
They might damage to cause panel surface variation and color change.
(4) Do not apply any strong mechanical shock to the LCD panel.
3.2 Operating Precaution
(1) Please be sure to unplug the power cord before remove the back-cover. (Be sure the power button is
turn-off)
(2) Please do not change variable resistance settings in MAIN-BOARD; they are adjusted to the most
suitable value. If they are changed, it might happen LUMINANCE does not satisfy the white balance
spec.
(3) Please consider that LCD backlight takes longer time to become stable of radiation characteristic in low
temperature than in room temperature.
(4) Please pay attention to displaying the same pattern for very long-time. Image might stick on LCD.
3.3 Storage Precaution
(1) When you store LCD for a long time, it is recommended to keep the temperature between -10°C -50°C
without the exposure of sunlight and to keep the humidity less than 85% RH.
(2) Please do not leave the LCD in the environment of high humidity and high temperature such as 60°C,
85%RH.
(3) Please do not leave the LCD in the environment of low temperature: below -10°C.
3.4 High Voltage Warning
The high voltage was only generated by INVERTER module on Power Board, if carelessly contacted the
transformer on this module, can cause a serious shock. (The lamp voltage after stable around 600V, with
lamp current around 8mA, and the lamp starting voltage was around 1500V, at Ta=25°C)

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4. Input/Output Description
4.1 D-SUB Connector
This procedure gives you instructions for installing and using the LCD TV display.
1. Position the display on the desired operation and plug the power cord into a convenient AC outlet.
Three-wire power cord must be shielded and is provided as a safety precaution as it connects the chassis
and cabinet to the electrical conduct ground. If the AC outlet in your location does not have provisions for
the grounded type plug, the installer should attach the proper adapter to ensure a safe ground potential.
2. Connect the 15-pin color display shielded signal cable to your signal system device and lock both screws
on the connector to ensure firm grounding. The connector information is as follow:
1
6
11 15
5
10
15 - Pin Color Display Signal Cable
Pin No. Description Pin No. Description
1 Red Video 9 No Pin!
2 Green Video 10 Sync Ground
3 Blue Video 11 Not Used
4 Not Used 12 Serial Data for DDC
5 Ground 13 H-Sync.
6 Red Ground 14 V-Sync.
7 Green Ground 15 Serial Clock for DDC
8 Blue Ground
3. Apply power to the display by turning the power switch to the "ON" position and allow about ten seconds
for Panel warm-up. The Power-On indicator lights "GREEN" when the display is on.
4. With proper signals feed to the display, a pattern or data should appear on the screen, adjust the
brightness and contrast to the most pleasing display, or press auto-adjust to get the best picture-quality.
5. This TV (with PC function) has power saving function following the VESA DPMS. Be sure to connect the
signal cable to the PC.
6. If your TV requires service, it must be returned with the power cord.

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4.2 Factory Preset Display Modes:
Analog RGB Signal Timing
Horizontal Vertical Sync Polarity Presence Screen Mode
Dots × Lines Frequency
(kHz)
Frequency
(Hz) Horizontal Vertical Horizontal Vertical Normal (4:3)
FULL
(16:9)
720×400 31.47 70.08
NEG POS YES YES YES YES
640×480 31.50 60.00
NEG NEG YES YES YES YES
640×480 37.50 75.00
NEG NEG YES YES YES YES
640×480 37.86 72.81
NEG NEG YES YES YES YES
800×600 37.90 60.32
NEG NEG YES YES YES YES
800×600 46.90 75.00
NEG NEG YES YES YES YES
800×600 48.08 72.19
NEG NEG YES YES YES YES
1024×768 48.40 60.00
YES YES YES YES YES YES
1280×768 47.7 60 YES YES YES YES YES YES
5. Front Panel Control Knobs

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6. Repair Flow Chart
6.1 No Power (No LED indicator)
NG
Check power cord and board interface Plug in power cord and interface
OK
Check F901, BD901, D910
NG Replace F901 or BD901 or D910
OK
Check IC930, Q930 (VCC1)
Check D970, D980
NG Replace IC930 or Q930
Check Q931, ZD930 (VCC2) NG Replace Q931 or ZD930
OK
OK
Check T901
OK
NG
Replace T901
Replace D970 or D980
OK
Check F970 (12V), F980 (24V)
Check PC950, TL950 (FB) Replace PC950 or TL950
OK
NG
NG
NG Replace F970 or F980 Check the load
OK
Check IC 960 NG Replace IC 960
OK
Check Q961, Q962 Replace Q961 or Q962
NG
OK
Check Q960 NG Replace Q960
Check F960 NG Replace F960
OK
Check the load
Check the load

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6.2 Can not start (LED indicator yellow)
NG Repair the keyboard
OK
Check 5V_SB NG Return to “6.1”
Check 3.3V_SB Replace U703 or F702
OK
NG
Check PWR_ON signal
OK
NG
Check Q703, Q708, Q704, Q911 NG Replace Q703 or Q708 or Q704 or Q911
Check U402, U403 NG Replace U402 or U403
Check I
2
C communication
OK
Check Q940 (VCC3) NG Replace Q940
Check PFC circuit NG Replace IC901 or Q901
OK
OK
Check main board power supply
Check keyboard
NG Replace panel
Check Panel inverter board