Datasheet LC-37HC40E Datasheet

LCD TELEVISION

LC-37HC40 E

CONTENTS

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

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

Method of BOOTCODE & FLASH burned in ............................................................

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

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

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

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

Troubleshooting guide ………………………………………………………………..……

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

APPENDIX-A: Assembly list

APPENDIX-B: Exploded View

3
5
9

16
17
18

20
21
26

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 must 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 necessary for the welder to wear anti static gloves.
Please refer to the part list before replacing components that have special safety requirements.
Do not replace with different components with different specs and type at will.

2. LCD servicing precautions

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

1

would be unable to work and no way to get it repaired.
If the connection wires, connections 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 dagmage.

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 Operation range 0 ~ +50 oC

Storage range -20 ~ +60 oC

Humidity Operation range 20% ~ 85%

Storage range 10% ~ 90%

2.13 Display of a fixed picture for a long time may cause a permanent after-image on the screen,
as commonly called “ghost shadow”. The degree of the after-image 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. Installation precautions

3.1 The front panel of LCD screen is made 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.

2

Alignment instructions

1. Test equipment

PM5518 (video signal generator)
VG-848 (VGA, HDMI signal generator)
CA210 (color analyzer)
PC (for writing HDCP KEY)

2. Alignment flow-chart

The alignment flow-chart is shown as fig-1

Check if FLASH,VGA EDID and USB FLASH (option) is written?

ADC correction of VGA, YPbPr

Fig-1 adjustment flow-chart

Check power voltages

Write HDCP KEY

Factory data initialization

White balance adjustment

Performance check

Preset ex-factory

3. Alignment instruction

Before alignment check if the program is written? Please refer to the software instruction (table3).

3.1 Power check
Connect all the boards according to wiring diagram. Check 5V-STB at standby, tuner 32V at
power on and backlight 24V.

3.2 Alignment
Connect all the boards according to wiring diagram then power on and check if the display is
normal?

Method for entering factory menu: press “INPUT”, “2”, “5”, ”8” and “0” in turn to enter factory

menu; press “CH+” or “CH-” to select adjustment items and press “VOL+” or “VOL-” to adjust
value items, press “MENU” repeatedly to exit. Set AGING MODE of the factory menu to ON,
AGING MODE icon will display on the top left of the screen, now you can press “NR” button to
enter the factory menu.

3

Method for software upgrading: Prepare the software upgrade program and set the software

upgrade tool correctly, press CONNECT then power on, the program will upgrade automatically.
After system prompts upgrade success, press EXIT to exit. When REALTEK appear, it means the
upgrade is complete, then restart the unit.

3.3 Write HDCP KEY
Turn on the PC and set the software tool correctly, click HDCP then turn on the unit, the program
will be written automatically. It needs about 5s and after finish, system will prompt upgrade
success.
Note: HDCP button can only be pressed one time for one unit.
The power should be off and 5V-STB disappear for 5s then start writing.

3.4 Initialization
Enter factory menu, press “CH+” or “CH-” to select adjustment items and press “VOL+” or “VOL-”
to enter the sub menu or adjust value items, adjustment items are shown in table1.

Table1 sub-menu adjustment

Items Preset Remarks

HOTEL OPT OFF ON: HOTEL OPTION of factory menu is available

OFF: HOTEL OPTION of factory menu is unavailable.

BACK LIGHT 0 Software will preset the data according the type of panel

LOGO OPTION ON ON: display LOGO when no signal is received or power on

OFF: no LOGO display

AGING MODE OFF OFF: power off when no signal

ON: aging mode

POWER MODE 0 0: standby 1: power on 2: memory

TEMP ADJUST→

ALL COLOR

RESET RESET Initialization (operate when EEPROM data chaos)

OFF ON: white balance of each channel auto offset based on the HDMI white

balance

0: white balance of each channel adjust the offset base separately

3.5 White balance adjustment

3.5.1 white balance adjustment of HDMI

a. Input VG-848 signal to HDMI port: TIMING85

signal of PAT920. Use color analyzer CA210 to adjust white balance.

4 (800x600/60Hz) and 16-level gray scale

BBY model should be adjusted
from BBY channel first. The unit must be working for above 30 mins to be in a stabler state for
adjustment.

b. Enter factory submenu of TEMP ADJUST, Select NORMAL color temperature (9300k),

fixed value of G OFF, adjust R OFF and B OFF, let the color coordinate of the third level be
(285±8, 293±12) and the brightness be about 3~5nit. Fixed value of G GAIN, adjust R GAIN and

B GAIN, let the color coordinate of the converse third level be (285+/-4, 293+/-6). Adjustment R
OFF, B OFF, R GAIN and B GAIN repeatedly until the value of the two levels gray-scale are about
(285, 293), then set ALL COLOR to ON.

4

For BBY model, select COOL color temperature (12000k), fixed value of G OFF, adjust
R OFF and B OFF, let the color coordinate of the third level be (272¡À5, 278¡À5) and the
brightness be about 3~5nit. Fixed value of G GAIN, adjust R GAIN and B GAIN, let the color
coordinate of the converse third level be (272+/-2, 278+/-2). Adjustment R OFF, B OFF, R GAIN

and B GAIN repeatedly until the value of the two levels gray-scale are about (272, 278), then set
ALL COLOR to ON.

3.5.2 VGA/YPBPR/AV white balance check and correction

a. Input VG-848 signal of VGA to VGA terminal: TIMING854(800x600/60Hz)
(PATTERN:CROSS) and auto adjust to full screen, then input PAT948 black/white signal, enter
factory menu ADC ADJ, select AUTO COLOR and the system will correct automatically, after
finish, it will return to AUTO COLOR menu. Please check the picture and data, if they are
abnormal, then the correction is failure and needs to correct again. (abnormal symptom: certain of
the data are greatly different from other data or exceed or near 1000).

Input PAT92
menu and set ALL

YPBPR check and correction

b.

0(16 gray levels), check if the white balance is normal, if not, enter TEMP ADJUST

COLOR to OFF and fine adjust according the method of 3.5.1b)

SD correction: input VG-848 signal of YPBPR to YPBPR terminal and input TIMING968

(480i) PAT968 color bar (see fig2), (color from left to right are white- yellow- cyan- green- purple-
red- blue- black), enter ADC ADJ submenu, select AUTO COLOR the system will correct
automatically, after finish, it will return to AUTO COLOR menu. Please check the picture and data,
if they are abnormal, then the correction is failure and needs to correct again.

HD correction: input VG-848 signal of YPBPR to YPBPR terminal and input TIMING976

(720P/60Hz) PAT968 color bar (color from left to right are white- yellow- cyan- green- purple- red-

blue- black), enter ADC

after finish, it will return

abnormal, then the correction is failure and needs to correct again.

ADJ submenu, select AUTO COL

to

AUTO COLOR menu. Please check the picture and data, if they are

OR the system will correct automatica

lly

,

fig2

Input PAT920(16 gray levels), check if the white balance is normal, if not, enter TEMP ADJUST

menu and set ALL

c. Input AV signal (PM5518, 8 gray levels, PAL for China and NTSC for America) to VIDEO

COLOR to OFF and fine adjust according the method of 3.5.1b)

terminal, check if the white balance is normal, if not, set ALL COLOR to OFF and fine adjust
according the method of 3.5.1b)

Note: it can’t set back to ON once ALL COLOR changes to OFF. The adjustment of other color

5

temperature refer to 3.5.

4. Performance check

4.1 TV function
Enter tuning menu → auto search, connect RF-TV terminal with central signal source and check if
the picture is normal, if there are channels not found. Check CCD and V-CHIP(for America).

4.2 AV/S, YPbPr jacks
Input AV/S, YPbPr/YCbCr HD signal, check if it is normal.

4.3 VGA jack
Connect VGA jack, input 640 x 480/60Hz standard signal and check if the display is normal.

4.4 HDMI jack
Connect HDMI jack, input 640 x 480/60Hz standard signal and check if the display is normal.
Check if HDCP is normal?

4.5 Check sound channel
Check the speaker and earphone output of each channel.

4.6 Check AV channel
Check if AV OUT is normal?

4.7 Other function check
Check the ON/OFF timer, sleep timer, picture/sound mode, OSD, freeze/mute, USB(option),
MAG.G feature, etc.

4.8 Presetting before ex-factory

Enter factory menu and select RESET, then the unit will be preset before ex-factory. The process
must be executed after the whole adjustment in factory.

Setting as follow without specified requirement.

Table2 ex-factory setting

Item Setting Item Setting Item Setting

PICTURE MODE NAUTRAL

DK (China),

or others

SOUND SYSTEM

SOUND MODE NEWS TRANSPARENCY 2

NR WEAK OSD TIME 10 ANTENNA CATV

ZOOM FULL

(depending

the local

area)

LANGUAGE English

VOLUME

VGA/HDMI COLOR

TEMP

20

STANDARD

5. Software instruction

Table3 software instruction

No. Code No. Type Function Written

Method Remarks

before

paste

NS3 5272540001 PM25VF040

NB1 5272402002 24C02N-10SI27 VGA EDID

Main CPU

program

Yes

Ye

Written with

instrument like

ALL11

6

Method of HC boot.img burned in

Boot.img burning processes:

1. Press “RTICE.EXE”, enter into the following interface:

Fig.1

Burning processes:
（1）Setting serial port: press “File”→ “Comm Settings…” as Fig.1, then
display the following interface as Fig.2;

Fig.2
Select COM port of your PC in “COM Port Selection”. For example, if
COM port of my PC is “COM4”, select “COM04”. Other items can be set
as shown above. Then press “OK” after setting.

（2） Press button “Burn in ROMCode” marked “E” in Fig. 1 to enter into
burning interface:

Fig. 3

Eight places are marked with red numbers and lines in Fig.3.

1 Select “Dragon/Washington ROM code with CTRL+Q”。
2 Select image file “boot.img ”.

3 Select “Bootcode”.
4 Confirm start address as “0x00000000”
5 Select “Erase” as Fig. 3.
6 Select “WPControl” as Fig. 3
7 Select “UpdateWriteStatus ” and “BIT2,3,4,5,7” as Fig. 3.

8 Press “TV Firmware”, then an interface is displayed as below：

Fig. 4
Burning process will begin after power-on and be completed until
“Programming Finish” displayed on the first line in above Figure. Power off
and then power on again.

Method of HC FLASH burned in

Flash.img burning processes：

1. Press “RTICE.EXE”, enter into the following interface：

Fig. 1

Burning processes:
（1）Setting serial port: press “File”→ “Comm Settings…” as Fig.1, then
display the following interface as Fig.2;

Fig. 2
Select COM port of your PC in “COM Port Selection”. For example, if
COM port of my PC is “COM4”, select “COM04”. Other items can be set
as shown above. Then press “OK” after setting.

（2） Press button “Burn in ROMCode” marked “E” in Fig. 1 to enter into
burning interface:

Fig. 3
Eight places are marked with red numbers and lines in Fig.3.

1 Select “Dragon/Washington ROM code with CTRL+Q”
2 Select image file “flash.img ”.
3 Select “Dragon ROS(4K)”.

4 Confirm start address as “0x00006000” （the item will be auto-set
after step 3）

5 Select “Erase” as Fig. 3
6 Select “WPControl” as Fig. 3
7 Select “UpdateWriteStatus ” and “BIT2,3,4,5,7” as Fig. 3
8 Press “TV Firmware”, then an interface is displayed as below:

Fig. 4

Fig. 5
Burning process will begin after power-on and be completed until
“Programming Finish” displayed on the first line in Fig.5. Power off and
then power on again.

Working principle analysis of the unit

The RF signal received from antenna will be sent to TUNER

obtained through high amplifier and mixed frequency, through pre-intermediate amplified by V415,
V416, it will be sent to SAW filter Z2 to IF filter and get better IF characteristics, then to main
chip NS1-66#,67# (R

Video and audio signals of AV1, AV2, S-VIDEO and YPbPr will be sent to main chip NS1.

Video and audio signals of VGA, HDMI1, HDMI2 will be sent to NS1, too.

The main chip NS1 is a high performance and fully integrated IC, which can realize HDMI
interface processing, video decoding, video switch selection, A/D and D/A conversion,
interlace/progressive processing, modes conversion, OSD and low-voltage differential output, etc.
And it also has functions of audio selection, processing and MCU feature. Video via RTD267
processing will send 4 pairs differential signals and 1pair clock signal to panel display.

Audio signal via NS1 processing will be sent to sound amplifier NS5 (TPA3120D2) to amplify
then sent to speaker.

TD2672).

401, then IF signal will be

2

10

Block diagram (for model without USB port)

TDQ-6FT/W114

(TUNER401)

X

SVEDIOY/C

AV2

AV OUT

AV1

YPBPR

VGA

24LC02EDID

HDMI1/2

RS232

Headphone
sound

AV 1 / S V I D E O

sound L/R channel

IF AMP

AV2 sound L/R channel

L/R sound

L/R sound

Sound pow

AMP.

TPA3120D2

RTD2672M

Main chip

Connect headphone, send
a HPDET signal from
headphone to main chip,
at this time there is no
sound from speaker.

L VDS

Display panel

D

D

R

memory

Soft

ware

mem

ory

IC block diagram

1. RTD2670 (main IC)

Pin description :

10-17: HDMI1 input

19-26: HDMI0 input

104: Horizontal SYNC input

37,38: VGA L/R input

58,59: external crystal vibrate

81,82: AV1 Y input

96-99: SPI bus

101: SDA

102: SCL

211,212: AV1 L/R

209,210: AV2 L/R

207, 208: VGA L/R

205, 206: YPBPR L/R
67,68: TUNER IF input

46-51: YPBPR input

40-45: VGA input

79,80: AV2 Y input

83,84,85,86: SVEDIO input

113-134: panel wires
5: backlight control
106: mute

TPA3120D2 (Sound power amplification)

2、

Pin description:

5,6: L/R input

22,15: L/R output

4: mute

Wiring diagram

Power Board

Main Board

USB Board

USB Connecting

Board

wiring for model with USB

Trouble shooting

1. Fault clearance

Before servicing please check to find the possible causes of the troubles according to the table

below.

1.1 Antenna (signal):

Picture is out of focus or jumping  Bad status in signal receiving

 Poor signal

 Check if there are failures with the electrical connector or

the antenna.

 Check if the antenna is properly connected.

Fringe in picture  Check if the antenna is correctly oriented.

 Maybe there is electric wave reflected from hilltop or

building.

Picture is interfered by stripe shaped

bright spots

There appear streaks or light color

on the screen

1.2 TV set:

Symptoms Possible cause

Unable to switch the power on  Check to see if the power plug has been inserted properly

No picture and sound  Check to see if the power supply of liquid crystal TV has

Deterioration of color phase or color

tone

Screen position or size is not proper  Check is the screen position and size is correctly set up.

Picture is twisted and deformed  Check to see if the picture-frame ratio is properly set up.

Picture color changed or colorless  Check the “Component” or “RGB” settings of the liquid

 Possibly due to interference from automobile, train, high

voltage transmission line, neon lamp etc.

 Maybe there is interference between antenna and power

supply line. Please try to separate them in a longer

distance.

 Maybe the shielded-layer of signal wire is not connected

properly to the connector.

 Check if interfered by other equipment and if interfered

possibly by the equipment like transmitting antenna,

non-professional radio station and cellular phone.

into the socket.

been switched on. (As can be indicated by the red LED at

the front of the TV set)

 See if it’s receiving the signal that is transmitted from other

source than the station

 Check if it’s connected to the wrong terminal or if the input

mode is correct.

 Check if the signal cable connection between video

frequency source and the liquid crystal TV set is correct.

 Check if all the picture setups have been corrected.

crystal TV set and make proper adjustment according to the

16

signal types.

Picture too bright and there is

distortion in the brightest area

 Check if the contrast setting is too high.

 Possibly the output quality of DVD broadcaster is set too

high.

 It maybe also due to improper terminal connection of the

video frequency signal in a certain position of the system.

Picture is whitish or too bright in the

darkest area of the picture

 Check if the setting for the brightness is too high

 Possibly the brightness grade of DVD player (broadcaster)

is set too high.

No picture or signal produced from

the displayer if “XXX in search”

appears.

There appears an indication -

“outside the receivable scope)

 Check if the cable is disconnected.

 Check if it’s connected to the proper terminal or if the input

mode is correct.

 Check if the TV set can receive input signal. The signal is

not correctly identified and VGA format is beyond the

specified scope.

Remote control cannot work

properly

 Check if the batteries are installed in the reverse order.

 Check if the battery is effective.

 Check the distance or angle from the monitor.

 Check if there is any obstruct between the remote control

and the TV set.

 Check if the remote control signal- receiving window is

exposed to strong fluorescence.

No picture and sound, but only

hash.

 Check if the antenna cable is correctly connected, or if it

has received the video signal correctly.

Blur picture  Check if the antenna cable is correctly connected.

 Of if it has received the right video signal.

No sound  Check if the “mute” audio frequency setting is selected.

 Check if the sound volume is set to minimum.

 Make sure the earphone is not connected.

 Check if the cable connection is loose.

When playing VHS picture search

tape, there are lines at the top or

bottom of the picture.

 When being played or in pause VHS picture search tape

sometimes can’t provide stable picture, which may lead to

incorrect display of the liquid crystal TV, In this case please

press “auto” key on the remote control so as to enable the

liquid crystal TV set to recheck the signal and then to

display correct picture signal

17

2. Troubleshooting guide

k

f

p

d

n

n

2.1. No raster

Turn-on power supply, chec

if the red indicator is light in

the STANDBY?

no

Check if pin9(5V) of X17 on

main board is normal?

no

Check STANDBY circuit o

ower supply board

Replace NS1

no

yes

Press POWER button on the

unit or sensor control an

check the indicator.

blue

Check if the pin3 of X12 o

main board is high-level?

yes

Check back light board

no

Check NS1

red

Check if the pin11 of X17 o

main board is high-level?

yes

Check power

supply board

18

2.2. Raster, but no picture

Check if the unit buttons

and remote control

operate normally?

no

yes

no

HDMI/VGA/YPRPB

Replace

main board

Does OSD menu

display normally when

press menu button?

yes

yes

Check TUNER401

and its periphery

yes

Check if all channels

have no signal?

no

Which channel has

no signal ?

TV

Check if output of

AVOUT is normal?

no

Check if output

IF signal of

no

TUNER401 (pin

11) is normal?

19

2.3.no sound (TV for example)

p

Check if pin1,3,10,12,19,

20 voltage of NS5 is

normal?

no

Check power supply

yes

Check the sound of

earphones is normal?

no

Check main chip if

MUTE is abnormal.

yes

Check NS5 and its

eriphery

20

Power

APPENDIX-A: Main assembly 9237HC4023

NAME NO.

MAIN COMPONENT AND IT'S NO.

Main board 6HC01501F0

Key board 6HC00405A0
IR board 6HC0152090
Power board 6HU0282010
Remote control 6010N03800
Panel 5203375501

NS1
NS5

RC-N38
V370B1-L01

RTD2672 （5272672001）

TPA3120 （5273120001）

APPENDIX-B: Exploded view (LC-37X40)

PART LIST OF EXPLODED VIEW

NO. DESCRIPTION

1

2

3

4

5

6

7

8

9

10
11
12
13
14
15
16

front cabinet
Side AV bracket
speaker
panel
panel fixed bracket
power socket
panel push board
screw
back cabinet
stand column
stand
IR board
key board
power board
digital processing board
interface baffle

Note: design and specifications are subject to change without notice.

9237HC4023

Ver.1.0