Xoceco LC-42FE32 Schematic

LCD TELEVISION

LC-42FE32

CONTENTS

Safety precautions………………………………………………………………………..…

Alignment instructions …………………………….…….…………………………………

Working principle analysis of the unit……………………………….………….………….

Block diagram …………………………………..………………………………….…………

IC block diagram………………………………………………………………………..……

Wiring diagram …………………………………………………………………………….

Troubleshooting….…..………………………………………………………………..……

Schematic diagram…………………………………………………………………………

APPENDIX-A: Assembly list

APPENDIX-B: Exploded View

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Attention: This service manual is only for service personnel to take reference with. Before

servicing please read the following points carefully.

Safety precautions

1. Instructions

Be sure to switch off the power supply before replacing or welding any components or
inserting/plugging in connection wire Anti static measures to be taken (throughout the entire
production process!):
a) Do not touch here and there by hand at will;
b) Be sure to use anti static electric iron;
c) It’s a must for the welder to wear anti static gloves.
Please refer to the detailed list before replacing components that have special safety requirements.
Do not change the specs and type at will.

2. Points for attention in servicing of LCD

2.1 Screens are different from one model to another and therefore not interchangeable. Be sure to
use the screen of the original model for replacement.

2.2 The operation voltage of LCD screen is 700-825V. Be sure to take proper measures in
protecting yourself and the machine when testing the system in the course of normal operation or
right after the power is switched off. Please do not touch the circuit or the metal part of the module
that is in operation mode. Relevant operation is possible only one minute after the power is
switched off.

2.3 Do not use any adapter that is not identical with the TV set. Otherwise it will cause fire or
damage to the set.

2.4 Never operate the set or do any installation work in bad environment such as wet bathroom,
laundry, kitchen, or nearby fire source, heating equipment and devices or exposure to sunlight etc.
Otherwise bad effect will result.

2.5 If any foreign substance such as water, liquid, metal slices or other matters happens to fall into
the module, be sure to cut the power off immediately and do not move anything on the module lest it
should cause fire or electric shock due to contact with the high voltage or short circuit.

2.6 Should there be smoke, abnormal smell or sound from the module, please shut the power off at
once. Likewise, if the screen is not working after the power is on or in the course of operation, the
power must be cut off immediately and no more operation is allowed under the same condition.

2.7 Do not pull out or plug in the connection wire when the module is in operation or just after the
power is off because in this case relatively high voltage still remains in the capacitor of the driving
circuit. Please wait at least one minute before the pulling out or plugging in the connection wire.

2.8 When operating or installing LCD please don’t subject the LCD components to bending, twisting
or extrusion, collision lest mishap should result.

2.9 As most of the circuitry in LCD TV set is composed of CMOS integrated circuits, it’s necessary
to pay attention to anti statics. Before servicing LCD TV make sure to take anti static measure and
ensure full grounding for all the parts that have to be grounded.

2.10 There are lots of connection wires between parts behind the LCD screen. When servicing or
moving the set please take care not to touch or scratch them. Once they are damaged the screen

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would be unable to work and no way to get it repaired.
If the connection wires, connectors or components fixed by the thermotropic glue need to disengage
when service, please soak the thermotropic glue into the alcohol and then pull them out in case of
damage.

2.11 Special care must be taken in transporting or handling it. Exquisite shock vibration may lead to
breakage of screen glass or damage to driving circuit. Therefore it must be packed in a strong case
before the transportation or handling.

2.12 For the storage make sure to put it in a place where the environment can be controlled so as to
prevent the temperature and humidity from exceeding the limits as specified in the manual. For
prolonged storage, it is necessary to house it in an anti-moisture bag and put them altogether in one
place. The ambient conditions are tabulated as follows:

Temperature Scope for operation 0 ~ +50 oC

Scope for storage -20 ~ +60 oC

Humidity Scope for operation 20% ~ 85%

Scope for storage 10% ~ 90%

2.13 Display of a fixed picture for a long time may result in appearance of picture residue on the
screen, as commonly called “ghost shadow”. The extent of the residual picture varies with the
maker of LCD screen. This phenomenon doesn’t represent failure. This “ghost shadow” may remain
in the picture for a period of time (several minutes). But when operating it please avoid displaying
still picture in high brightness for a long time.

3. Points for attention during installation

3.1 The front panel of LCD screen is of glass. When installing it please make sure to put it in place.

3.2 For service or installation it’s necessary to use specified screw lest it should damage the screen.

3.3 Be sure to take anti dust measures. Any foreign substance that happens to fall down between
the screen and the glass will affect the receiving and viewing effect

3.4 When dismantling or mounting the protective partition plate that is used for anti vibration and
insulation please take care to keep it in intactness so as to avoid hidden trouble.

3.5 Be sure to protect the cabinet from damage or scratch during service, dismantling or mounting.

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Alignment instructions

1. Test equipment

Digital Multi-meter
54200 (Signal generator)
PC (FLASH writing programs have to be installed first, W24CXX.EXE)
VG849 (HDMI signal generator)
CA210 (White balancer)
DVD player (with HDMI output)
Monitor

2. The alignment flow chart (see below figure)

Production of main board, high frequency board,

other little board, power board on the line.

ADC emendation and white balance adjustment

Connect to central signal source, check
various TV functions (station search, system
identify, modulate quantity control etc), check if
the output of earphone and speaker are normal
Picture and sound of AV-out is normal. (check
stereo/SAP and CCD, VCHIP for America) .

FLASH write N5, N9, N13, N24

High frequency board test

Main board test

Test of Button board and IR board

Combined test for general assembly

Aging

Fig.1 Flow process of alignment

Check accessories and then packing

Input VGA signal, check if display is normal in

the state of PC and various functions (analog

control), line/ field center etc. the picture and

sound of AV-OUT should be the picture and

sound of the current channel

Input HDMI and DVI signal (use a connection

wire, input audio signal from D-sub Audio in),

check if HDCP KEY, picture and sound are

normal.

the picture and sound of AV-OUT should

be the picture and sound of the current channel

Input YPbPr/YCbCr 1/2 signal and check if

picture, sound and analog quantity control is

normal in the state of COMPONENT. the picture

and sound of AV-OUT should be the picture and

Input AV1/S/AV2 signal, check various functions
under each terminal (system identify, analog
control etc), check if Picture and sound of AV-out
is normal. (S-terminal and AV1 share the same
audio channel, the output picture from AV-out is
the picture of AV1 in the status of S-terminal)

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3. Flash writing programs

Flash write N5, N9, N13, N24
Flash write W24CXX.EXE to N13, N24 with self-made flash write tool on the line.
Note: software upgrade of N5 from socket X51

software upgrade of N9 from USB interface
software upgrade of N13, N24 from HDMI and VGA interface separately

Adjustment of main board and high frequency board

a) Connect the main board and high frequency board according the wiring diagram. Connect X402

(on main board) with IR board and insert the plug of power supply assy into X707, now the
indicator light of IR board is red.

b) Press POWER button on the remote control set, now the indicator light of IR board is blue.

c) Check if picture and sound are normal of all the channels, if STEREO/SAP can be identified

correctly. Check AV-OUT function: the picture and sound of AV-OUT should be the picture and
sound of the current channel at TV/AV1/S/AV2; the sound from AV-OUT should be the sound of
the current channel at the other signal source, while the picture don’t need to check.

4. Unit adjustment

4.1 Adjustment of unit connection

Turn on the TV and check if it is normal: display LOGO about 8 seconds later, display picture about
12 seconds later.

4.2 Aging

a) Turn on the TV, select TV channel without signal input.

b) Aging for an hour in the aging room.

4.3 ACD calibration and White balance adjustment (use CA210, VG849 generator)

Method of entering factory menu: enter “INPUT” menu, then press”2 5 8 0” one by one.

Note: Coordinate of cold color temperature 9300K is (X=283, Y=299), coordinate of warm color
temperature 6500K is (X=311, Y=329).

YPbPr channel (YPbPr1 or YPbPr2)

a) Input SMPTE COLOR BAR signal of 480P (TIMING:976, PATTERN:984)

b) Set brightness to 50; contrast to 50

c) Enter factory menu and perform “Calibration”

VGA channel

a) Input 16-level gray scale signal of the mode 800*600 @60 (TIMING:885, PATTERN:920)

b) Set brightness to 50; contrast to 50

c) Enter factory menu and perform “Calibration”

d) Select “color temperature” of “COOL”

e) Enter “color temperature setting” menu

f) Fix GREEN GAIN at 128, adjust RED GAIN, BLUE GAIN to set the color coordinates of

fourteenth level to (X=283, Y=299).

g) Set the color coordinates of warm color temperature (WARM) to (X=311, Y=329) using the

same method.

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h) Check if the color coordinates of the cool/warm color temperature at YPbPr (include 480i,

480P, 720P, 1080i), VIDEO(NTSC, PAL) and TV channels are within the scope of the
corresponding value (permit ±8 error).

5 Functional Inspection

5.1 TV function
Connect RF terminal to the central signal source, Enter Search menu → auto search, check if there
is station skipping. Check if Fine Tune, the output of earphone and speakers, and the picture are
normal. Check STEREO/SAP/CCD/Parent Control and the picture and sound from AV-OUT.

5.2 ATSC function
Connect AIR terminal to the central signal source, press INFO button and check if the information is
right. Open EPG table and do the same check. Open CCD, V-CHIP and check the display.

5.3 AV/S-Video terminal
Separate input AV1/S/AV2 signal, check if they are normal. Check if the picture and sound from
AV-OUT is normal. It should auto-jump to S terminal when insert S-terminal at the status of AV1.

5.4 VGA terminal
Input VGA signal (VG849 signal generator), separate input the VGA format signal of table 1 and
check if the display and sound are normal. If the image is slight disturb, press auto correction button
on the remote control and check the display.

Table1 PC signal format

No Resolution H-frequency(kHz) V-frenquency(Hz)

1 720×400 31.47 70.08 25.17 DOS

2 640×480 31.50 60.00 25.18 DOS

3 640×480 37.90 72.00 31.50 Mac.(SOG)

4 640×480 37.50 75.00 31.50 VESA

5 640×480 43.30 85.00 36.00 VESA

6 800×600 35.16 56.25 36.00 VESA

7 800×600 37.90 60.00 40.00 VESA

8 800×600 46.90 75.00 49.50 VESA

9 800×600 48.08 72.19 50.00 VESA

10 832×624 49.00 74.00 57.27 Mac.(H+V)

11 1024×768 48.40 60.00 65.00 VESA

12 1024×768 56.50 70.00 75.00 VESA

13 1024×768 60.00 75.00 78.75 VESA

14 1280×1024 64.00 60 108.00 SXGA

15 1280×1024 80.00 75 135.00 SXGA

5.5 YPbPr terminal
Input YPbPr signal (VG849 signal generator), separate input the format signal of table 2, check if
the image and sound is normal. If the image is slight disturb, press auto correction button on the
remote control and check the display.

Point clock pulse
frenquency(MHz)

Remark

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Table 2 Component mode

No Resolution H-frequency(kHz) V-frenquency(Hz)

720×480 15.734 59.94 13.5 480i(NTSC)

1

2 720×576 15.625 50 13.5 576i(PAL)

720×480 31.469 59.94 27 480p(NTSC PROG)

3

4 720×576 31.25 50 27 576p(PAL PROG)

1280×720 45 59.94 74.18 720p(59p)

5

6 1280×720 45 60 74.25 720p(60p)

1280×720 37.5 50 74.25 720p(50p)

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8 1920×1080 33.75 59.94 74.25 1080i(59i)

1920×1080 33.75 60 74.25 1080i(60i)

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10 1920×1080 28.125 50 74.25 1080i(50i)

5.6 HDMI terminal
Input HDMI signal (VG849 signal generator), separate input the format signal of table 3 and table 4.
Check if the image and sound is normal. Input DVI signal through DVI-HDMI trans-connection wire,
input audio signal from DVI/VGA AUDIO and check if it is normal.

Table 3 HDMI signal format

No H-frequency(kHz) V-frenquency(Hz) Remark

1 15.735 60 SDTV 480i

2 15.625 50 SDTV 576i

3 31.47 60 SDTV 483p

4 45.00 60 HDTV 720p

5 33.75 60 HDTV 1080i

Table 4 HDMI audio signal format

Channel 2

Sampling frequency 32 Kbit/s, 44.1 Kbit/s, 48 Kbit/s

Wide 16 bit, 20 bit, 24 bit

Point clock pulse
frenquency(MHz)

Remark

6 Ex-factory preset

Enter the factory menu in the status of TV, then perform the ex-factory preset.

7 Packing

Check the accessories and then packing.

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Working principle analysis of the unit

1. Video signal flow (see below figure)
TV VIDEO signal(TV1, TV2) output from TUNER1 and TUNER2 is divided into two ways, one way
is sent to PW328 process of main-picture; another way is sent to TVP5147 process of sub-picture.
Likewise, analog video signal of AV1, AV2, Y/C is divided into two ways and separate sent to
PW328 and TVP5147 to do the same process. In addition, 44MHZ digital IF signal output from
TUNER1 is sent to N717 demodulating for TS(0:7), then it send to PWM2000 to do the
corresponding process, then switch to RGB of 30bit output to PW328, the signal of TV1,TV2, AV1,
AV2, Y/C input into TVP5147 digital processing and convert into 20bit YC signal output to PW328;
while digital signal of YPbPr1,YPbPr2 and VGA send straight to PW328. The differential signal of
HDMI-1 and HDMI-2 via HDMI receiver SIL9011 after, demodulate 30bit RGB signal output to
PW328 too. The all signal input into PW328 digital processing then send to LVDS level drive for
LCD panel. In addition, TV1, TV2, AV1 and AV2 via QS3257 select after, send to X704 for output of
video.

Tuner 1

Tuner 2

V-out

Tuner 1

AV 1

AV 2

YCbCr

YPbPr 1

YPbPr 2

VGA

HDMI-1

HDMI-2

IF

TV1

TV2

3257

T312

VSB/QAM

Demodulator

30-BIT RGB

PWM328

SiL9011

TS

PWM2000

TVP5147

20-BIT Y/C

LVDS

30-BIT RGB

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2. Audio signal flow (see below figure)
SIF1, SIF2 of TUNER1 and TUNER2 send straight to MSP4440G demodulate of MTS. The signal
and the sound of AV1, AV2, VGA and YPbPr1, YPbPr2(via PIV331 to select signal),send to
MSP4440G select output. CL/WS of HDMI-1, HDMI-2 and digital MEPG_CL/WS demodulated from
PWM2000 via 3257 select after, it send to MSP4440G, while the data D1 and D2 of HDMI and
PWM2000 send straight to MSP4440G. IIS and the audio signal of each channel are demodulated
in MSP4440G then sent to TPA3008 amplify and output. The audio signal of TS stream may be
demodulated and converted into SPDIF to output in PWM2000 at the same time.

Audio out

Tuner 1

SIF1

SIF2

Tuner 2

AV 1

AV 2

VGA

MSP4440G

PIV331

3257

IIS D1

Mepg cl/ws

Hdmi cl/ws

IIS D2

PWM2000

SiL9011

YPBPR 1

HDMI-1

YPBPR 2

HDMI-2

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I2C

Block diagram

DDR

128M

FLASH

4MBITS

DDR

64M

MASTER

TV1

PWM2000

CPU

MPEG 2 decode

TS

T312

TUNER1

slowbus

30bit RGB

PWM328

SCALER

20BIT Y/C

lvds

Panel

RS-232

TV2

TUNER2

TVP5147

DECORDER

AV 1 / S

30BIT RGB

PIV331

YPrPb1

YPrPB2

2X amplify V-OUT

HDMI/DVI-2

IR Key

PIV331

ATMEGA8L

SII9011

HDMI

receiver

Note:

HDMI/DVI-1

VGA

Earphone

Video signal

Audio signal

I/O signal

Digital audio signal

HD signal

Digital signal

Speaker

MSP4440

Sound processor

TPA3008

Sound amplify

Earphone

NJM1109

Earphone amplify

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IC block diagram

1. PWM2000

Feature:

 Main frequency of RSIC CPU up to 200MIPS
 USB controller
 MPEG2 decoder
 Intelligent controller
 Audio decode, supports formats of all kinds. In this system, it decodes TS audio signal,

supports SPDIF output.

Pin descriptions:

Pin Type Name Instruction

AN8 IRQ5 IR2000 Remote reception

AK9 IRQ1 EXTINT_328 V-sync send to PWM2000 judge of

signal

AK10 IRQ0 INTENETn Net adjustment board interrupt

(DEBUG emulation)

AK11 PIO17 VO_SEL0

AN10 PIO20 VO_SEL1

AK13 PIO9 AUDIOSEL Select HDMI/MPEG I2S output

AL13 PIO8 AUDIOSEL_Y Selection of YPBPR input audio

AL12 PIO11 BK_ON Backlight control: 0=OFF 1=ON

AK12 PIO10 LCD_ON Power supply control of panel:

AM11 PIO15 HOT_PLUG Hot-plug control

AM13 PIO7 OSCOFF A/D conversion of main tuner

AN13 PIO6 SID Detect of SVIDEO input (SVIDEO

AN14 PIO5 MUTE Control of mute

AK14 PIO20 RF_SW Select RF input (AIR/CABLE)

Selected video output
(TV1, TV2, AV1, AV2)

0=OFF 1=ON

prior)

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2. PWM328

Feature:

 Supports V-CHIP, CCD, OSD
 DEIMTERLACING
 SCALING
 PIP/POP
 Integrated ADC, VIDEO DECODER

Block diagram is follow:

Pin descriptions:

Pin Type Name Instruction

M1 PORTA0 SBBE0

M2 PORTA1 SBBE1

D24 ADC0 KEY1_328

Enable control of bus line of bit
store

Button

C26 ADC1 KEY2_AD_IN

A10 PWM0 BRIGHT Brightness of backlight control

Description of main periphery components:
R62: amplitude adjustment of LVDS output, the resistance bigger, the LVDS amplitude smaller.
R259: DDR clock matching resistor for PWM328. in this system, DDR clock up to 180MHZ. The

resistor is 0ohm for compatible 200MHZ.
R263-R269: DDR matching resistor
R721, R724: matching resistor for HD synchronizing separator circuit
C268: isolating capacitor for SOG separator circuit of VGA signal
R478: matching resistor of SLOWBUS 50MHZ clock signal

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3. TVP5147

Feature:

 VEDIO DECORDER of sub-picture
 BT 601 20-BIT 4:2:2 YCbCr output

Block diagram is follow:

Description of main periphery components:

C19, C20, C22, C23, C27: isolating capacitor for video input
R18: I2C sub-address select pin
R19: connect to the ground to insure the signal format output of BT.601
R22: indicator pin of odd-even bit output: select pin of BT.601 signal format output

4. SII9011

Feature:

 HDMI1.1 and DVI1.0 compatible receiver, integrated HDCP1.1
 Supports digital interface of all kinds, this system supports 30bit RGB output
 Color space convert
 Four channels I2S outputs, sampling frequency up to 192KHZ
 Audio protection

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