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LCD COLOUR TV

SERVICE MANUAL CHASSIS NO.:LS03W

Please read this manual carefully before service.

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Catalog Chapter 1: Specifications and Composition ......................................3

Chapter 2: Function Introduction of Main ICs ...................................5

Chapter 3: Analysis of Signal process flowchart and key point

measure date ......................................................................7

Chapter 4: Maintenance Procedure and Examples of Typical

troubleshooting ...................................................................9

Chapter 5: Factory Setup...................................................................15

Appendix 1 Circuit Schematic Diagram ............................................18

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Chapter 1: Specification and Composition

1. Main Feature

Region

America

Color

system

NTSCPAL MPAL N RF signal

Sound

system

M

Video or Y/C signal

PALNTSCSECAM

Program presetting 68 AIR2-69

125 CABLE1-125 Audio outputTHD

7%

6W+6W

Power source

100V240V

CCD

Yes

Sound demodulator

BTSC

VGA input

Yes

YPBPR input

Yes

HDMI input

Yes

OSD language

English, French, etc.

Auto Off without

Signal Reception 15 minutes

Energy saving systemCustomer could adjust LCD screen backlight brightness manually to save

energy.

Plug and Play LCD TV could be used as computer screen, no need for the installation of

software, which is Plug and Play in real sense

2. Unit IC Compositions

The LT32GR01U is made up of switch power, system control circuit, video processing circuit, audio processing circuit, Power Amplifier circuit, AV input circuit, LCD screen module. Block circuit diagram is shown as below:

TUNER AV1/AV2 LVDS S-VIDEO YPbPr1/YPbPr2 VGA HDMI

Audio1(for AV1/YPbPr1/S-VIDEO)

Audio2(AV2/YPbPr2)

Audio3(VGA)

POL4558 Audio switch

AMP TPA300BD2

Sound effect

POL4558 HCF4052

TV Audio

PANEL MST9U19 DECODER/SC LAER

3. Introduction of PCB module The LT32GR01U is made up of power board, Side TV board, remote control reception board, key board, and mainboard. The table below is the introduction of the function of all printed Board modules. No Parts Description

1

Mainboard

Module

Mainboard module is the core of LCD TV signal processing. Under the

control of the system control circuit, It undertakes the task of converting the

external input signal into the unified digital signal that the LCD screen could

identify. Mainboard controls the whole machine through IIC bus, decode

VIDEO signal, controls the Video (brightness, contrast, chroma, hue,

definition etc), white balance adjusts, generates OSD, de-interlaces signal,

converts signal frequency, and finishes signal A/D and D/A conversion,

video enhancement, LVDS signal coding and output; it has Scart , S-Video,

AV , YPbPr, HDMI and PC interface, Tuner input, sound demodulation,

sound processing, sound power amplifier, and online update.

2

Remote reception

module

The remote reception board module is constituted by an indicator-light and

a remote reception. Customer could manipulate the LCD TV by using

remote controller very conveniently. By the color of the indicator light, the

operation mode of the LCD TV could be judged (red is standby, green is

power on).

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3 Built-in power board module

Convert the 100V240V 50/60HZAC into DC, output have +24v, +12V, +5V, and the +5V_STB in standby state.

4 Keyboard module

Keyboard module has 7 function keys (program +/-, volume +/-, AV/TV, menu ,power), customer could use the key to operate the TV freely.

5 LCD screen module

LCD screen has built-in inverter that convert DC into high voltage AC signal to turn on the backlight CCFL (Cold Cathode Fluorescent Light); the LCD screen process the video signal from signal board and reappear.

6 TV board TV board is used for RF signal.

Chapter 2: Function Introduction of Main ICs 1. Main ICs and functional modules of the LT32GR01U Mainboard

No. Item no. Model Main function

1 U10 MST9U19 Video decoder, Audio signal processor, image processor, A/D and D/A conversion

2 U2 EONP40-50GCP Flash, Store the Control program.

3 U1 AT24LC32 EEPROM

4 U3 SI9435 MOS switch

5 U4 TPA3008D2 Audio amplifier

6 U5 CM1117ADJ-3.3 5V to 3.3V DC conversion

7 U6 BM1084ADJ-1.8 3.3V to 1.8V DC conversion

8 U7 BM1084ADJ-3.3 5V to 3.3V DC conversion

9 U11 CD4052B Audio switch

10 U12 PI5V330S Video switch

11 U13 FM24C02 EEPROM

12 U14 FM24C02 EEPROM

TV board

No. Item no. Model Main function

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1 U1 TSN6312-N Tuner output sound IF and video signal

2 U2.U3 78M05 12V to 5V DC conversion

Function introduction of ICs or functional modules of the LT32GR01U 1.Tuner (JS-6H2/121 or CDT-6GPL22-00)

Pin No. Definition of pin Function description 1 Ground Ground 2 Ground Ground 3 VCC +5V power 4 SCL IIC bus (clock) 5 SDA IIC bus (data) 6 AS Ground 7 NC No connection 8 NC No connection 9 Ground Ground 10 Ground Ground 11 SIF/Out Sound intermediate Frequency output

12 Video/Out CVBS signal output

13 VCC+5V +5V power 14 Audio/Out Audio signal output

2. Image processing IC MST9U19 Main features: Integrated 6th Generation Motion and Edge Adaptive De-interlacing Integrated ADC PC auto tune Built-in 8-bit LVDS Transmitter 6th generation cubic-4 image scaling engine Advanced Chroma Processing and Dynamic Contrast Function Green color stretch, blue color stretch, skin color enhancement Integrated 6th Generation Motion Adaptive 3D Digital Comb Video Decoder with Programmable Filter 60Hz/100Hz interlaced scanning and 50Hz/75Hz progressive scanning frame rate conversion Advanced Film Mode Recovery-3:2/2:2 pull down Build-in A/D conversion function Teletext function Supports 16/32bits SDRAM memory interface Multi-screen display mode OSD and VBI/Closed caption and advanced OSD engine

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Chapter 3: Analysis of Signal process Flowchart and key

point measure date

This chapter mainly introduces the receipt and dispose of AV signal, the power supply system and system control process of this TV.

1. Video signal flow RF signal is demodulated by tuner, then the obtained video signal and signals inputted

from COMPONENT terminal, 2-way AV, S-VIDEO, 2-way YPBPR interface, VGA interface and HDMI interface are all sent into video-processing IC MST9U19 for decoding. The different format input signals are changed into uniform LVDS signals, and are sent to LCD screen.

2. Sound process flow RF signal is demodulated by tuner, and then the obtained SIF signal (SIF-2 signal) is

directly processed by MST9U19. The output audio signal of MST9U19 is sent into power amplifier TPA3008D2.

Signals from HDTV terminal, AV terminal, YPBPR interface and PC Audio are also sent into MST9U19 for demodulation and sound process. The output audio signal is sent into power amplifier TPA3008D2,

3. Power supply system There are 4 ways of voltage output in the power panel: +24V6A+12V2A+5V

2Aand +5VS1A. +24V output is provided for LCD screen; +12V output is provided for power amplifier TPA3008D2. +5V output is changed into 1.8V output and 3.3V output by DC/DC to satisfy the needs ICs. +24V, +12V and +5V outputs will be cut off in standby state. While +5VS output is the power supply of infrared receiver and EEPROM etc, and will be cut off when the AC is turn off. (1) The composition and distribution of the TV power supply

12VAUDIO

AUDIO_MUTE circuit

+12V power supply J4

Pin 10.11

U4 power amplifier TPA3008D2 Pin14.15.22.23.33.38.39.46.47

V_VIDEO

U11 CD4502B Pin16

U10 PI5V330 Pin16 +5V

power supply J4

Pin 3,4

+5V

_LC

+5V_4052

8

+5V

STB

pow

er su

pply

J4 P

IN2

+5V

stb

LC

POWERDOWN_A

U6 BM1084ADJ +1.8V_LDO

U1 AT24LC32 Pin8

CM1117ADJ +3.3VA_LDO

U7 BM1084ADJ +3.3V_LDO

VDDC1.8V U10 MST9U19 Pin77.98.107.142.158.203

U2 EONP40-50GCP

Back light height control

U10 MST9U19 Pin88.100.102.103.119.140.151.159.172.186

+3.3V_ADC

Back light switch control

IIC Bus data interface

IIC Bus clock interface VDDP_3.3V

U10 MST9U19 Pin 36

U10 MST9U19 Pin 60 +3.3V_AU

+3.3V_SIF U10 MST9U19 Pin 53

+3.3V_MEMPLL U10 MST9U19 Pin 105

+3.3V_HDMI U10 MST9U19 Pin 6.12

+3.3V_MPLL U10 MST9U19 Pin 157.208

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4. Position and definition of the main components and sockets on mainboard

Socket definition

Serial number

Position number

Connecting object Function description

1 J1 Keyboard and Remote control receiving board

+5V,LED-GRN,LED-RED,MENU,SEL,UP,DOWN, LEFT,RIGHT,POWER,REMOTR,GND

2 J4 Inverter GND,GND,INV-ADJ,INV-ON,+12V,+12V

3 J7 Power In POWERDOWN-AC,+5VSTB-IN,+5V,+5V,VCC-PANNEL,VCC-PANNEL,GND,GND,GND,+12V,+12V

4 J5 Speaker R+,R-

5 J6 Speaker L+,L-

6 J11 TUNER SCL.SDA,TV-AFT,GND,IF,GND,CVBS,GND,AF, GND,+5V,+5V,GND,12V

7 J9 LVDS VCC,VCC,VCC,VCC,VCC,GND,GND,GND,GND,GND,LVB0-, LVB0+, LVB1-, LVB1+, LVB2-, LVB2+, LVBCK-, LVBCK+, LVB3-, LVB3+, LVA0-, LVA0+, LVA1-, LVA1+, LVA2-, LVA2+, LVACK-, LVACK+, LVA3-, LVA3+

Chapter 4: Maintenance Procedure and Examples of Typical

troubleshooting

Power troubleshooting

the pin 2 of J7 is 5V or not?

check Power Module

the pin3/4 of J7 is 5V or not

the pin10/11 of J7 is 12V or not

the input of AC is right or not check 3.3V output of U5

1.8V output of U6, 3.3Voutput of

U7

OK Detect and repair the Electricity Networks

LDO is broken or the load is short circuit

OK

Y N

Y N

Y N

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Display troubleshooting 1.

Blank Screen or the image showed

abnormal (backlight is light)

Panel Interface cable connect well

and ecactly

LCD is right or

not?

change

Panel Interface cable

Y N

change

the LCD

N Y

check the output networks,

J8 and circuit between U10 and J8

Y N

Check power and Clock circuit

of U10

repair this

circuit

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2.

3.

Blank Screen

Pin4 of J4 is 5V

Chenk the 24V of Power Module

Check the control circuit,

netwoork of Q2 and pin 110 of U10

N

N Y

Y

check Power Module

Inverter is broken or the cable

connect not well

White Screen

Panel power voltage is right

N Y

Pin4 of U3 is low voltage?

Check the output of U10

Check the Pin 5/6 of J7

(5V or 12V)

Check the circuit between this pin and

U3 or I/O of U10 is broken (pin 112).

N Y

LCD or Panel Interface

cable is broken

U10 is broken or

power supply

irregular

Y N

Check J7and the related circuitChange U3

N Y

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Audio troubleshooting

NO SOUND

1. check audio input

2. check power supply of power amplifier

1.Check the

audio

peripheral

equipment

2.check the

power circuit

of power

amplifier

Check the input signal of pin2,6 of U4

N

Y

Y N

the set up of Volume and mute are right

Rein-

stall

The output signal of J5 and J6 is existed

Y N

Check

The

Speaker

Check the circuit of

power amplifier

Check pin 54.55.66-69 of U10

Whether exist the input

N

Y

Check the output signal of

U10(pin 74.75)

U10 is broken or power

supply is not good

Y N

Check the

Input equipment

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TV troubleshooting

1.

2.

TV do not tune/ there is no picture

The input of RF is normal

N

Check the

RF

peripheral

equipment

Y

check pin 3.13 of tuner whether is 5V

Check the

power

supply of

this pin

Y N

Check the I2C of tuner (PIN4.5)

Check I2C network

(connect with pin

131.132

of U10)

N Y

Check the pin12 of tuner whether it has signal

N

Check

pin49 of

U10 and

filter

network

Y

Tuner is broken .change the tuner

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PC troubleshooting

YP/CbP/CrS- VideoAV troubleshooting

IN PC MODE

The picture Is not

in the middle

color is

abnormal

The image jitter On signal

Auto adjust

Check the R G B input of U10 is right

The setup is not

correct.

Reset.

Y N

Check the

R G B circuit

Check the HS and VS

is regular and steady

Check the

VS,HS circuit

Setup of osd is not

matching or do not

support the input

Check the

VS,HS circuit

Y N

TV has the picture but no picture

There has sound in PC/AV mode

N Y

Check the pin11 of the tuner whether it has signal output

Check the connection between

Mainboard and TV board.

The tuner

Is broken.

Y N

Y

Refer the audio

troubleshooting

process

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Chapter 5: Factory Setup Enter factory menu

Switch to TV Cable mode, and make LCD at operating state: Press MUTE key on remote control Press number key 919 on remote control to enter password.

The detailed setting items are given bellow: Setting method INDEX

0. Version 1.Picture Nonlinear 2. Picture Mode 3.Sound Nonlinear 4. Sound Mode 5. Offset Gain 6.Picture Adjustment7. 9Win

Press key to enter submenu

YP/CbP/CrS- VideoAV

color is abnormal

YP/CbP/Cr

No signal

All no signal

The setup is not

correct.

Reset.

Check the Y, P/Cb, P/Cr

Input network

Check

U10

Check the power of

U10 and Crystal

Oscillator X1.

Check the Y, P/Cb, P/Cr input of U10 is right

Y N

AldoText BoxEntre en el men de fbrica Cambie al modo de TV por cable, y crea LCD en estado de funcionamiento: Pulse MUTE en el control remoto; Presione la tecla nmero "9", "1", "9" en el control remoto para introducir la contrasea

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8. Function 9. Factory setting A. Hotel Setting

submenu of each item Use keys on remote control to make up or down option and usekeys to set. 1.Picture Nonlinear

Item Setting value Port VContrast 0-63-128-191-255 VBrightness 0-63-130-191-255 VSaturation 0-63-128-191-255 VSharpness 0-4-8-12-16

2. Picture Mode Item Setting value Brightness 50 45 55 50 Contrast 50 45 55 50 Hue 50 50 50 50 Saturation 50 35 65 50 Sharpness 50 40 50 50 Picture Mode Normal Soft Vivid User

3. Sound Nonlinear Item Setting value Bass 0-6-12-18-24 Treble 0-6-12-18-24

4. Sound Mode Item Setting value Bass 50 40 60 50 Treble 50 40 60 50 Sound Mode Normal News Movie User

5. Offset Gain Setting value Item R G B

Offset 127 127 127 Gain 127 127 127 Auto Color Video Col Tem. Normal Cool Warm User Video R 50 50 55 50 Video G 50 50 50 50 Video B 50 55 50 50 PC Col Tem. Normal Cool Warm User

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PC R 50 50 55 50 PC G 50 50 50 50 PC B 50 55 50 50

6. Picture Adjustment

Item Setting value Port Display the input mode Mode Type Color, sound system, or input format

TV AV1 AV2 S-VIDEO YPBPR1 YPBPR2 PC HDMI Picture H.SIZE 42 42 42 20 21 Picture V.SIZE 26 24 23 18 17 Picture H.Pos H 0 0 0 0 1 Picture H.POS L 135 134 112 109 23 Picture V.POS.H 0 0 0 0 0 Picture V.POS.L 7 7 3 22

According to various format, the value is not fixed

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8. Function Item Setting value First Language English TTX Language WEST Sound SYS M/N Color SYS NTSC DNR MID

9. Factory Setting Item Setting value Disable all Power OFF Buring Mode OFF

10.Hotel Setting Item Setting value Hotel Mode OFF Volume Control OFF Tune Control OFF Max Volume 100

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Appendix 1 Circuit Schematic Diagram(see next page)

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