Xoceco LC-22KE46 Schematic

LCD TELEVISION

LC-22KE46

CONTENTS

Safety precautions………………………………………………………………………..… Alignment instructions …………………………….…….………………………………… Block diagram…………………………………..………………………………….………… Working principle analysis of the unit……………………………….………….…………. IC block diagram………………………………………………………………………..…… Trouble shooting…….………………………………………………………………..…… Wiring diagram ……………………………………………………………………………. 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

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 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.

Alignment instructions

1. Test equipment

VG-848 (YPbPr,VGA signal generator) VG-849 (HDMI signal generator) CA210 (white balance equipment)

2. Alignment flow

2.1 Voltage of power supply test

According to the wiring diagram specified by product specification, connect power board, digital

board, IR/key board and backlight board correctly; then power on and press key

to turn on the

unit.

a) Test voltage of power socket each pin in turn listed as Table 1. (X601 for below 26’’ and X501

for 26’’ and above)

Table 1 Voltage of 13-pin power socket each pin

Pin 1 2 3

4、5 6、7

8 9 10 11 12 13

Voltage ≥2.5V ≥2.5V 0 12 V±5% 0 N.C. 5 V±5% 0 5 V±5% 0 ≥2.5V

b) Test voltage of power socket each pin in turn listed as Table 2. (X506 for 26’’ and above)

Table 2 Voltage of 5-pin power socket each pin

Pin 1, 2 3, 4, 5

Voltage 24V±5% V 0

2.2 Adjustment flow chart shown as Fig.1

Check if EDID, HDCP KEY and FLASH have been burned.

Combination adjustment for general assembly

White balance adjustment

Connect to central signal source, check if TV functions are normal

–omitted channel, analog parameters control, etc; check if output of

earphone and speaker is normal.

Input AV or Y/C signal，check if every function is normal.

Input YPbPr signal，check if every function is normal.

Input RGB signal，check if the display is normal; check if every

function is normal –analog parameter control, horizontal/vertical

center, etc.

Input HDMI signal，check if the display is normal; check if every

function is normal –analog parameter control, horizontal/vertical

center, etc.

Connect to USB device, check if the display is normal; check if

every function is normal –analog parameter control,

horizontal/vertical center, etc.

Check if other functions are normal –LCN, OTA, etc.

Ex-factory setup

Check accessaries and packing

Fig.1 Adjustment flow chart

3. Alignment instruction

3.1 Unit adjustment

3.1.1 According to the wiring diagram specified by product specification, connect power board,

digital board, IR/key board and backlight board correctly; then power on and check if the

display is normal.

3.1.2 Using method of factory menu

a) First press key “SOURCE”，then press number key “2、5、8、0” in turn to enter into initial

factory menu;

b) Press keys “▲” and “▼” can move cursor to each page of initial factory menu, then press key

“OK” to enter into adjustment menu of each page;

c) Press keys “▲” and “▼” can move cursor upwards and downwards within one adjustment

page;

d) Move cursor to one adjustment item, then press keys “◄” and “►” can adjust it;

e) Press key “MENU” can exit adjustment menu of one page to its superior factory menu;

f) Press key “EXIT” can exit factory menu at any time;

g) Press key “OK” can enter into inferior factory menu;

h) Factory menu item “ADC Calibrate” is used to correct ADC of VGA Component channel;

i) Factory menu item “W/B ADJUST” is used to adjust white balance;

j) Factory menu item “POWER MODE” is used to set power-on mode, “Standby” means the set

will be in Standby state after power-on; “ Memory ” means the set will in the last power-off

state after power-on ; “ForceOn” means the set will be working automatically after power-on ,

the mode is also used for factory-machine-aging; default setting should be “Standby” mode

unless specified by customer requirement;

k) Factory menu item “ISP MODE” is used to upgraded unit software from VGA port when the

item is set as “ON” and the set is connected to ISP adjustment equipment; DDC function of

VGA port will be recovered when the item is set as “OFF”; the value of the item can not be

kept in the memory, that is to say the item is reset as “OFF” after power-on again;

l) Factory menu item “RESET ALL” is used to reset factory menu data and user menu data;

execute the item then the set will be started up again and the startup guided picture will be

displayed also;

m) Factory menu item “FACTORY CHANNEL PRESET” is used to preset factory programs data;

it is necessary to connect to central signal source for DTV searching programs. Now digital

frequency of central signal CH40(626 MHz) is distributed to HK DTMB programs. Primary

preset programs would not be modified along with the changing of central signals, so please

select item “DTV Manual Tuning” in menu Channel to manual search digital programs, the

process will spend about 15s;

n) Factory menu item “CUSTOM CHANNEL PRESET” : first delete all DTV/ATV programs for

factory adjustment, then preset DTV/ATV channel data according to customer order

requirements; please execute the item to clear out all programs for factory adjustment before

leaving factory;

o) Factory menu item “MST DEBUG”: Default is “OFF”. Engineering sample with RS-232

functions matches the design specifations when the item is set as “OFF”; It’s convenient to

adjust with equipment when it’s set as “ON”. The value of the item can not be kept in the

memory, that is to say the item is reset as “OFF” after power-on again;

p) Factory menu item “BACKLIGHT” is used to adjust backlight brightness, test voltage of

13-pin power socket and adjust the item to meet the requirement of maximum PWM voltage

in panel specification; the software having been preset according to model need not be

adjusted;

q) Factory menu item “SSC ADJUST” is used to adjust expended functions of frequency content,

the software having been preset according to model need not be adjusted;

r) Factory menu item “Others”-> “Audio curve” is used to adjust volume curve; the software

having been preset according to model need not be adjusted unless special customer

requirements;

s) Factory menu item “Software upgrade” is used to upgrade USB, after select confirm the

software will search AP.bin stored in USB device to upgrade at any channel ; If the software

has been upgraded or E

PROM has data, please select and execute operation “RESET ALL”

before adjustment for the first time.

3.1.3 ADC correction of Component channel YPbPr

a) Switch to Component channel; b) Press key “SOURCE”，then press number keys “2、5、8、0” to enter into initial factory menu;

c) Move cursor to item “ADC Calibrate” and press key “OK” to enter into interior factory menu; d) Input Component signal (VG-848 Timing:969(PAL)，Pattern:918 100% color bar), move

cursor to item “MODE”，press keys “▲” and “▼” to select item “YPbPr（SD）”, then move

cursor to item “AUTO ADC” and press key “OK” to begin adjustment automatically until a

prompt “success” for adjustment completion is displayed;

e) Input Component signal (VG-848 Timing:972(1080i)，Pattern:918 100% color bar), move

cursor to item “MODE”，press keys “▲” and “▼” to select item “YPbPr（HD）”, then move

cursor to item “AUTO ADC” and press key “OK” to begin adjustment automatically until a

prompt “success” for adjustment completion is displayed.

3.1.4 ADC correction of RGB channel

a) Switch to RGB channel (D-SUB channel); b) Press key “SOURCE”, then press number keys “2、5、8、0” to enter into initial factory menu;

c) Move cursor to item “ADC Calibrate” and press key “OK” to enter into interior factory menu; d) Input RGB signal (VG-848 Timing:856(1024×768/60 Hz)，Pattern:920 8 step Gray), move

cursor to item “MODE”，press keys “▲” and “▼” to select item “RGB”, then move cursor to

item “AUTO ADC” and press key “OK” to begin adjustment automatically until a prompt

“success” for adjustment completion is displayed.

3.2 White balance adjustment

Unless specified by customer, default COOL color temperature is 12000K, chromaticity coordinates is (272、278); default Standard color temperature is 9300K, chromaticity coordinates is(285、293); default Warm color temperature is 6500K, chromaticity coordinates is (313、329).

3.3 White balance adjustment processes

The set should be working above 30 minutes before white balance adjustment for it would be in a

stabler state. Use white balance apparatus CA-210 and switch to its BBY channel.(19” for

example)

a) Switch to HDMI channel； b) Press key “SOURCE”, then press number keys “2、5、8、0” in turn to enter into initial factory

menu;

c) Move to item “W/B ADJUST” and press key “OK” to enter into interior factory menu; d) Input HDMI signal (VG-848 Timing: 856(1024×768/60 Hz)，Pattern:921 16 step Gray),

move cursor to item “MODE”, press keys “▲” and “▼” to select item “HDMI”, then move cursor to item “TEMPERTURE”, press keys “▲” and “▼” to select item “COOL”；

e) Fix item “G GAIN”, adjust item “R GAIN、B GAIN” to set chromaticity coordinates of the 13

step is (272、278)；

f) Fix item “G OFFSET”, adjust item “R OFFSET、B OFFSET” to set chromaticity coordinates of

step is (272、278)；

the 4

g) During adjustment , make sure that color temperature of bright step is (X=272±5,Y=278±15)

and color temperature of dark step is (X=272±8,Y=278±30);

h) Then move cursor to item “COPY ALL” to copy white balance data to the other channels;

i) Check if color temperature of STANDARD and WARM meet requirements as below:

STANDARD: allowable error of bright step is (X±10, Y±15), allowable error of dark step is

(X±10,Y±25); WARM: allowable error of bright and dark step are both (X±10,Y±10);

otherwise adjust items “R_GAIN /B_GAIN/R_OFFSET/B_OFFSET” to meet requirements and

then save data;

j) Check if the white balance of the other channels meet the requirements, if not, adjust the data

and save separately.

k) Check if the picture of every channel is normal after adjustment;

l) Adjustment rules for reference as below:

adjust B gun: adjust B gun value downwards , then coordinates of X、Y will rise; adjust B gun value upwards , then coordinates of X、Y will descent;

adjust R gun will effect the coordinate of X and the value of Lv a little:

adjust R gun value upwards , then coordinate of X will rise;

adjust R gun value downwards , then coordinate of X will descent;

adjust G gun will effect the coordinate of Y and the value of Lv a lot:

adjust G gun value upwards , then coordinate of Y will rise;

adjust G gun value downwards , then coordinate of Y will descent;

4. Performance check

4.1 TV functions

Connect RF port to central signal source, first enter into menu Channel, then search programs automatically, check if there is any omitted program of AT V、DTV, check if the output of speakers

is normal, check if the picture is normal.

4.2 Composite AV or Y/C ports

Input AV signal or Y/C separate S-Video signal, check if the picture and the sound are normal

under the circustances of power-on, switching channel,switching signal format, etc.

4.3 Component port (Y, Pb, Pr)

Input Component signal from signal generator VG-848 with the formats as Tab l e 3 respectively,

check if the display and the sound are normal under the circumstances of power-on/off, switching

channel, switching signal format, etc.

Table 3 Component receiving signal formats

Horizontal

No. Definition

1 720×480 15.734/15.75 59.94/60 13.5/13.514

2 720×576 15.625 50 13.5

3 720×480 31.469/31.5 59.94/60 27/27.027 480p

4 720×576 31.25 50 27 576p

5 1280×720 37.5 50 74.25 720p (50p)

6 1280×720 44.955/45 59.94/60 74.176/74.25 720p (59.94p/60p)

7 1920×1080 28.125 50 74.25 1080i (50i)

8 1920×1080 33.75 59.94/60 74.176/74.25 1080i (59.94i/60i)

9 1920×1080 26.973 23.976 74.176 1080p (23.97p)

10 1920×1080 27 24 74.25 1080p (24p)

11 1920×1080 28.125 25 74.25 1080p (25p)

12 1920×1080 33.716 29.97 74.176 1080p (29.97p)

13 1920×1080 33.75 30 74.25 1080p (30p)

14 1920×1080 56.25 50 148.5 1080p (50p)

15 1920×1080 67.432/67.5 59.94/60 148.35/148.5 1080p (59.94p/60p)

frequency

（kHz）

Vertical frequenvy

（Hz）

Dot-pulse

frequency

（MHz）

Remark

480i (NTSC,

NTSC4.43,PAL60,PAL-M)

576i (PAL, PAL-N,

SECAM)

4.4 R,G,B port

Input RGB D-SUB signal from signal generator VG-848 with the formats as Table 4 respectively,

check if the display and the sound are normal under the circumstances of power-on/off, switching

channel, switching signal format, etc. if there is any deviation of line or field, enter into main menu

and select items “Picture->Screen->Auto Adjusting” in turn to correct them automatically.

Table 4 R,G, B receiving signal formats

Horizontal

No. Definition

1 640×480 31.469 59.94 25.175 IBM

2 720×400 31.469 70.086 28.322 IBM

3 640×480 37.861 72.809 31.5 VESA

4 640×480 37.5 75 31.5 VESA

5 800×600 35.156 56.25 36 VESA

6 800×600 37.879 60.317 40 VESA

7 800×600 48.077 72.188 50 VESA

8 800×600 46.875 75 49.5 VESA

9 1024×768 48.363 60.004 65 VESA

10 1024×768 56.476 70.069 75 VESA

11 1024×768 60.023 75.029 78.75 VESA

12 1152×864 67.5 75 108 VESA

13 1280×960 60 60 108 VESA

14 1280×1024 63.98 60.02 108 VESA

15 1280×1024 80 75 135 SXGA

16 1360×768 47.7 60 85.5 WXGA

17 1440×900 55.9 60 106.5 WXGA+

18 1400×1050 65.22 60 122.61 SXGA+

19 1680×1050 65.3 60 146.25 WSXGA+

20 1920×1080 67.5 60 148.5

frequency

（kHz）

Vertical

frequenvy

（Hz）

Dot-pulse

frequency

（MHz）

Remark

4.5 HDMI port

Input HDMI signal from signal generator VG-849 with the formats as Ta b l e 5, check if the display and the sound(32 KHz、44.1 KHz、48 KHz) are normal under the circumstances of power-on/off,

switching channel, switching signal format, etc.

Table 5 HDMI receiving signal formats

Horizontal

No. Definition

1 640×480 31.469/31.5 59.94/60 25.175/25.2 640×480p@59.94/60Hz

2 720×480 31.469/31.5 59.94/60 27/27.027 720×480p@59.94/60Hz,4:3/16:9

3 1280×720 44.955/45 59.94/60 74.176/74.25 1280×720p@59.94/60Hz

4 1920×1080 33.716/33.75 59.94/60 74.176/74.25 1920×1080i@59.94/60Hz

5 720(1440)×480 15.734/15.75 59.94/60 27/27.027 720(1440)×480i@59.94/60Hz,4:3/16:9

frequency

（kHz）

Vertical frequenvy（Hz）

Dot-pulse

frequency

（MHz）

Remark

6 720(1440)×240 15.734/15.75

7 (2880)×480 15.734/15.75 59.94/60 54/54.054 (2880)×480i@59.94/60Hz,4:3/16:9

8 (2880)×240 15.734/15.75

9 1440×480 31.469/31.5 59.94/60 54/54.054 1440×480p@59.94/60Hz,4:3/16:9

10 1920×1080 67.432/67.5 59.94/60 148.352/148.5 1920×1080p@59.94/60Hz

11 720×576 31.25 50 27 720×576p@50Hz,4:3/16:9

12 1280×720 37.5 50 74.25 1280×720p@50Hz

13 1920×1080 28.125 50 74.25 1920×1080i@50Hz

14 720(1440)×576 15.625 50 27 720(1440)×576i@50Hz,4:3/16:9

15 720(1440) ×288 15.625

16 (2880) ×576 15.625 50 54 (2880)×576i@50Hz,4:3/16:9

17 (2880) ×288 15.625

18 1440×576 31.25 50 54 1440×576p@50Hz,4:3/16:9

19 1920×1080 56.25 50 148.5 1920×1080p@50Hz

20 1920×1080 26.973/27 23.97/24 74.176/74.25 1920×1080p@23.97/24Hz

21 1920×1080 28.125 25 74.25 1920×1080p@25Hz

22 1920×1080 33.716/33.75 29.97/30 74.176/74.25 1920×1080p@29.97/30Hz

Mode1 59.826/59.886

Mode2 60.054/60.115

Mode1 59.826/59.886

Mode2 60.054/60.115

Mode1 49.761

Mode2 49.92

Mode3 50.08

Mode1 49.761

Mode2 49.92

Mode3 50.08

27/27.027 720(1440)×240p@59.94/60Hz,4:3/16:9

54/54.054 (2880)×240p@59.94/60Hz,4:3/16:9

27 720(1440)×288p@50Hz,4:3/16:9

54 (2880)×288p@50Hz,4:3/16:9

4.6 USB port

Connect the USB device with picture, sound and video documents and check if the picture, sound

and functions are normal.

4.7 Other functions check

a) Check if the functions are normal -timing turn-on/off、sleeping turn-off、picture/sound mode、

OSD、stereo and digital audio interface, etc.;

b) Check if Audio Only digital programs are normal;

c) Check if function of logic channel number (LCN) is normal;

5. User menu setup before leaving factory

Enter into page “LOCK” of user menu and iput the initial password “0000 “, select submenu

“Restore Factory Default” then press “OK“ to preset items before leaving factory as below:

a) Clear out all programs information;

b) Clear out information of block program and favorite channels;

c) Default setup of user analog data;

d) Set Menu Language as Chinese;

e) Set Power on MODE as Standby.

6. Instruction of factory software burning as Table 6

Table 6 Instruction of factory software burning

Location

size

Below

26”

and

above

No.

N103 5271280501 MX25L12805DMI-20G

N105 5272404002 AT24C04 HDCP KEY Yes

N402

N405

N417

N206 5272402002 AT24C02 VGA EDID Yes

N103 5271280501 MX25L12805DMI-20G

Part No. Part type

5272402002 AT24C02 HDMI EDID Yes

Note 1: Write-protect setup method

Enter into interface of burning program ALL-100, select item “Config”, press item “config

Setting”, set item “Protect” as “All Protect”. Be sure to select item “Config” before burning

software, and write-protect must be re-set after burning program ALL-100 startup every time.

Instruction

of software

function

Main

program

Main

program

Burned

before

SMT

Yes

Burning method

burned with program

ALL100, write-protect setup,

refer to Note 1 in detail

burned with program

ALL100

burned with program

ALL100

burned with program

ALL100

burned with program

ALL100, write-protect setup,

refer to Note 1 in detail

Note 2: Burning and upgrading software method with burning tool ISP

1） Main board upgrading: connect 4-core line of burning tool ISP to Debug port（location No. XM04

for below 26” and No. X505 for 26” and above）of main board;

Unit upgrading: connect both VGA ports between burning tool ISP and main board, then enter into

factory menu and set item “ISP Mode” as “ON”;

2） Use on-line burning tool of Mstar, enter into menu “Device”, select item “WP Pin pull to high

during ISP” as Fig. 2 to make sure hardware write-protect of Flash is canceled and the erasing

process will be normal;

Fig. 2 Write-protect setup

3) Select menu “Connect”, a dialog “Device Type is MX25L12805D” will be displayed as Fig. 3

to show succeeding in connecting. If failing to connecting, select the first menu “Device” and

manual select item “MX25L1280D”, then press key “Connect”.

Fig. 3 Successful connection

4) Press key “Read”，select burning file (for example AP.bin) as Fig. 4.

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