Xoceco LC-22K9 Schematic

COLOR TELEVISION

LC22K9

CONTENT

Safety instructions………………………………………………………………………..…

Instructions on adjusting and testing…………………………….…….…………………

Trouble shooting……………………………………………………….……………………

Principle analysis of LC-22K9……………………………………….………..………….

LC22K9 BLOCK DIAGRAM…………………………………………………………………0

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

Components No…………………………………………………………………………….…

Identification criteria for the bright spot and dark spot of the LCD screen………..….

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

Exploded views…………………………………………………………………………..…

Schematic diagram…………………………………………………………………….…..

Attention: This service manual is only for service personnel to take reference with. Before servicing please read the following points carefully.

Safety instructions

1. Instructions

1.1 Be sure to switch off the power supply before replacing or welding any components

or inserting/plugging in connection wire

1.2 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.

1.3 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.

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

0---+50 C

operation

Scope for

- 20----60 C

storage

humidity Scope for

20%---85%

operation

Scope for

10%---90%

storage

2.13. Display of a fixed picture for a long time may result in appearance of picture residue on the screen,

as commmonly called “ghost shadow”. The extent of the residual picture varies with the maker of LCD screen. This phenonmenon 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. Wheng installing it please make sure to put it in place.

3.2. For service or instatallation 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.

Instructions on adjusting and testing

The adjustment of LC22K9 excludes 2.30

2.1 Adjusting and calibrating the equipment

PM 5518(video frequency signal generator), K-7253(VGA signal generator),CA210(white balancer)

2.2 Adjustment and calibration procedure

2.3 Adjusting and calibrating the monitor board

Place the monitor board on the testing jig, turn on the power supply and switch on the set to see if it is normal.

2.3.1 Adjusting the white balance of monitor board

Push the “Rest” key and “OK” key under the cover of the remote control set, repeat the push, enter

the factory menu. Select factory reset to initialize the MONITOR

Input the DVI signal to monitor board. (K-7253 time339 pattern 630 8 gray degree signals, input the DVI signal to socket with 26 cores of monitor board by way of patch panel). Adjust the intermediate second and seventh gray degree with CA210 white balancer. Preset value of R,G,B CUT to 100,and R,G,B DRV to 150, then, adjust the second gray degree (brightness: about 9nit) by R,G,B CUT, to set the color coordinates of second gray degree to 270, 283. Adjust R,G,B DRV to set the color coordinate of seventh gray degree to 270 and 283.

Note: Because the values of R,G,B CUT and R,G,B DRV directly determines the values of brightness and contrast at the DVI terminal of monitor board, the white balance should be adjusted according to the preset value strictly. The value after adjusting should be within +/-10 of the preset value.

2.3.2 Calibrating ADC of Monitor After finishing the adjustment of 2.3.1, set the VGA signal to 1024X768 60Hz mode. Access the

pane signal and connect it to VGA terminal of monitor. Adjust h port of the picture to make the picture fully occupy the screen. Enter the factory menu and select items for ADC calibration and calibrate the ADC according to the indication on the screen.

2.3.3 Adjusting the white balance of monitor:

Input 8 gray degree signals of 1024X768 60Hz mode, push “display” key on the remote control

set, adjust brightness and contrast, to set the brightness of second gray degree to 5nit and seventh as 400nit.

For the diagram of adjustment and calibration procedure, see diagram 1

B CUT and B DRV is fixed as 128. Adjust R G CUT,to make second degree of the color coordinate as 270 283. Adjust R G DRV to set seventh degree of the color coordinate to 270

283. Adjust R G CUT and R G DRV again and again, until both of the two gray degrees are at 270 and 283.

2.4 Connect decoder board and push button board with the monitor board verified to be normal (LC-30K9/LC40K9 power is as per connection diagram 203-L30K90-01JL whereas LC-22K9 is as per 203-L22K90-01JL). After power on, observe if the display is normal.

Method to enter factory menu: Continuously push key of “VOL+” “Mute”, “Video” to enter factory

menu. When the first line of each and every adjusting item is in the highest brightness push

Production of the main board and decoders on the line

General assembly and combined calibration

Connect central signal source, check T functions (station skipping, analog quantit control etc) . Check if the output of speake is normal

Input AV/S and HDTV signal and chec following functions of the terminals

Input VGA signal (one format), check i display is normal under the PC status, an functions (analog control), central of line an field etc.

Check accessories, then packing

Figure 1. Adjustment and calibration procedure

Check if FLASH is written

Check Monitor board

Check decoders in media board

“ENTER” key to select different adjustment items. When VGA and DVI are input, select “mode” and then push “ENTER” key and select three color temperatures 6500K,9300K,12000K. Push “MENU” to quit factory menu.

Notice: Adjustment of Media Box must be performed under the mode --”Nature” of picture.

2.4.1 EPROM Initialization

Enter the first page of factory menu, select clear eprom and push “ENTER” key, shut off the set after

the appearance of “OK”.

2.4.2.Adjustin VGA and DVI channel

2.4.2.1 Presetting the VGA channel mode

Input VGA signal from K-7253 (PATTERN 5),select IME301,push “AUTO” to automatically adjust the picture to be in full screen. Also auto-adjust TIME302,TIME303,TIME311,TIME313,TIME315,TIME316,TIME317,TIME319,TIME339 respectively.

2.4.2.2 Adjusting ADC of VGA channel Input K-7253 TIME311,PATTERN474 64 degree of gray signal, adjust adc-gain to maximum (no bigger than 20), and to set two neighboring brightest degrees distinguishable.

2.4.2.3. Adjusting white balance of VGA and DVI channel Input eighth degree of gray signal K-7253 TIME311 and PATTERN471, enter adjustment menu of white balance, and use white balancer to adjust second and seventh degree of gray signal. Select mode to be 6500K, adjust offset_R,offset_G,offset_B, to set second color coordination to 313 293 and the brightness to about 5nit.Fix gain_R as 128, adjust gain_G,gain_B to set seventh color coordination to 313 293. Adjust offset_R,offset_G,offset_and gain_G,gain_B,again and again until two gray degrees are 313 and 293. Selct mode to be 9300K, adjust offset_R,offset_G,offset_B, to set second color coordinate to 281,311 and the brightness to about 5nit.Fix gain_G as 128, adjust gain_R,gain_B to set seventh color coordinate to 281, 311.Adjust offset_R,offset_G,offset_and gain_R,gain_B,again and again until two gray degrees are 281 313.

Select mode to be 12000K, adjust offset_R,offset_G,offset_B, to set second color coordinate to 270 283 and the brightness to about 5nit.Fix gain_B as 128, adjust gain_R,gain_B to set seventh color coordinates to 270, 283. Adjust offset_R,offset_G,offset_B and gain_R,gain_G,again and again until two gray degrees are 270 283.

Notice: The value of gain_R,gain_G,gain_B should not exceed 128.

2.4.3. Adjusting TV channel

2.4.3.1. Adjusting sub-brightness and sub-contrast of VCO and OPTION Input AV color bar signal (PM 5518 COLOUR BAR 100%) to terminal of VIDEO 1, enter the first page of factory menu, select auto color, push”ENTER”key. After two seconds, display of OK shows the completion of adjustment. Adjust the value of Option to 9, S-brightness to 124,and S-contrast

140.

2.4.3.2 Adjusting white balance of TV channel Input AV signal, (PM 5518 gray signal ),enter the adjustment menu of white balance, adjust second and seventh degrees by white balancer. Adjust offset_R,offset_G,offset_B, set the second color coordinate to 270 283 and the brightness to about 5nit.Fix gain_R as 133, adjust gain_R gain_G to set the seventh color coordinate to 270 283.Adjust offset_R,offset_G,offset_B and gain_R,gain_G,again and again until two gray degrees are 270 283.

2.4.4 Adjusting white balance of YPbPr channel

Input YPbPr signal of K-7253 to terminal of YPbPr, input 8 gray degree signal to

TIME380(480i)PATTERN471, adjust S-brightness to 20,and S-contrast 140. Enter adjustment menu of white balance, adjust second degrees by white balancer. Adjust offset_R,offset_G,offset_B to set the second color coordinate to 270 283 and the brightness to about 5nit. Separately input the eighth degree of gray signals of TIME392(480p),TIME394(720p)and TIME396(1080i)mode. Repeat the above operation so that the second color coordinates are 270 283 and the brightness about 5nit.

3. Functional inspection

3.1 TV function Enter search menu---auto search, connect central signal to RF terminal and check if there is missing of station. Input A21 signal and check the function of CCD.

3.2 AV/S HDTV terminal Input HDTV signal to AV/S, and check if it is normal.

3.3 VGA connector

Insert VGA signal connector, input 640 x 480@60 Hz VGA format signal, and check if display is normal. If there is interfere on the picture, push the auto-adjust key on the remote control set once more, check if the display is normal.

3.4 Inspection of PCMCIA channel

Insert PCMCIA card, switchover to this channel, and check if the display is normal.

3.5 Inspecting sound channel

Inspect if the output of speaker and earphone of channels is normal.

Trouble shooting

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

1.Antenna:

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

 Maybe broadcast signal itself is not good  Check if the outdoor antenna is disconnected.  Check if the antenna is correctly oriented.

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

 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.

 Check if interfered by other equipment and if interfered

possibly by the equipment like transmitting antenna, non professional radio station and cellular phone.

2.TV set:

Symptoms Possible cause

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

the socket.

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

Picture too bright and there is distortion in the brightest area

Picture is whitish or too bright in the

darkest area of the picture

No picture or signal produced from

the displayer if “XXX in

search”appears. There appears an indication “outside the receivable scope)

Remote control cannot work properly

No picture and sound, but only

hash.

 Check if all the picture setups have been corrected.

TV set and make proper adjustment according to the signal types.

 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.

 Check if the setting for the brightness is too high  Possibly the brightness grade of DVD player(broadcaster)is

set too high.

 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.

 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.

 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 TVIn 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

Principle analysis of LC-22K9

For the working principle of LC-22K9 please refer to LC-22K9 block diagram of the complete TV set.

Following is a short description of the signal flow:

RF signal through an integral tuner TUNER201 produces complete color TV signal which is input, together with AV1/SVHS(SVHS in priority)AV2 and PCMCIA video signals, into U29 VPC3230D for conversion selection and decoding. Except for being decoded the selected video signal is divided in two routes: one is fed to AV output terminal and another route of signal to special 21 line decoder U32 Z86229 of CCD/V-CHIP for decoding. After decoding by U32, the signal is sent back to U29 with R,G,B,FB format and superimposed to the original picture decoded, then sent to U13 FLI2310 in ITU-R656 of 8B1T format for progressive line processing.

YPbPr signal, after analog to digital conversion by U30 MST9883 into YUV with 24BIT is also sent to FLI2310.

Above two routes of signal are processed by FLI2310 for matrix, color density and tint and then output as RGB with 24 BIT into the main processor chip U12 JAG-ASM. There are other two routes of signals: one route is RGB signal of VGA for computer, another route is DV1 into RGB signal with 24 bit to U12 through interface of U15 TFP403/501. Three routes of signal are processed in U12 for picture format. Among them, one route of VGA after A/D conversion for RGB is subject to selection for conversion, together with other two routes, and then processed for digital display including OSD AND GAMMA correction, and brightness and contrast processing and changed into 1024*768 format. The RGB signal with 24BIT is output to the LVDS converter, U31 DS90C383A, for conversion into the signal format which the screen can accept, that is, three pairs of low voltage differential signal and one pair of time signal. And they are further sent to LCD screen for picture display. The PWM of U12 is also used to control the brightness of the background light. The second sound IF signal SIF output from tuner is sent to sound frequency processor N201 MSP3420; the sound frequency signal of YPRPB,DVI and PCMCIA is also sent to N201 after switching over and selection by switch U34 HEF4052. The AV1/SVHS,AV2 and VGA audio signal are also sent to N201 respectively, where the second sound IF SIF is first demodulated to the audio signal which, together with four way audio signal, is selected for conversion, and then further sound magnitude controlled and sound effect treated. The output of left and right signal R/L is divided into two routes: one is sent to SRS sound field processor N203 M62494 for SRS surrounding sound processing, and further used to drive the speaker after the D-type sound power amplification N207 LX1722 and amplification of N205,N206,N208,N210 SI4532DY; the other route is used to drive earphone after power amplification N212 TLE2142. Power is supplied from power adapter and then converted into the power required by various channels and circuits.

LC22K9 BLOCK DIAGRAM

VGA

DVI

AV1-V/S-Y

SVHS-C

AV2-V

PCMCIA-YUV

AV-V OUT

YPrPb

U15 DVI receiver

TFP403/501

TUNER201

VIDEO DECODER

VPC3230

U32

CCD V-CHIP Z86229

U30

ADC

MST9883

U29

FBV

RGB

SIF

ITU-R656

8bit

24bit YUV

RGB 24bit

U13

DEINTER

LACER

FLI2310

U14

SDRAM

I C BUS

EEPROM

RGB 24bit

U12

SCALER

RGB 24bit

JAG-ASM

U19

SDRAM

U20

SDRAM

MICRO-CONTRLER

TSC80251G2D

U31

LVDS

DRIVER

DS90C383A

KEY BOARD

FLASHMEMORY

PANEL

SIF AV1/SVHS-R/L AV2-R/L VGA-R/L

PCMCI-R/L YPrPb-R/L DVI-R/L

AV-R/L OUT

KEY(POWER)

HEF4052

U34

PROCESSOR

U24 Microcontroller ATTINY12L

N201

AUDIO

MSP3420

ON/OFF

POWER

R/L

SRS 3D STEREO

CONTROLLER

R/L

N205-N208 N210

AMPLIFIER

N203

M62494

R/L

D-CLASS

AUDIO

LX1722

Si4532DY

N212

TLE2142

R/L

HEADPHONE

SPEAKER

Block diagram and description of LC-22K9 main IC

1.MSP3420

Loud-

Subwoofer

speaker

Headphone

SCART1

SCART2

DAC

Loud-

Sound

speaker

Processing

Pre-

processing

De-

modulator

DAC

Sound

Processing

Headphone

Prescale

DAC

Source Select

Select

Output

SCART

DAC

Prescale

ADC

DSP

Input

ADC

Sound IF1

Sound IF2

SCART

SCART1

SCART2

Select

SCART3

SCART4

Pins description: 2,3 PIN:SCL,SDA applied for control the operation of IC . 27,28 PINAoutput left and right sound channel R/L to speaker processor. 36,37 PIN:AV OUT of sound R/L. 47,48 PIN:DVI/YPRPB/PCMCIA selected input R/L. 50,51 PIN:Input of VGA. R/L 53,54 PIN:Input of AV2 R/L. 56,57 PIN:Input R/L of SVHS/AV1(SVHS priority) 67 PIN:Input TV SIF.

MONO

2.VPC3230

CrCb

Y OUT

Output

2D Scaler

OUT

YCOE

FIFO

CNTL

Control

ITU-R 656

Formatter

PIP

ITU-R 601

Mode

Panorama

Memory

Contrast

Peaking

Brightness

H Sync

V Sync

LL Clock

Sync

Clock

AVO

Generation

C Bus20.25 MHz

C Bus

Clock

Gen.

Mixer

Color

Adaptive

Analog

CIN

Pins description: 4 PIN: Input U of PCMCIA. 5,73 PIN: Input Y of PCMCIA. 6 PIN: Input V of PCMCIA 31-34, 37-40 PIN:output format signal of.ITU-R656 70 PIN:Video of AV OUT 71 PIN:Input C of SVHS. 72 PIN:input Video (SVHS in priority) of Y or AV1 of SVHS. 74 PIN:input Video of AV2. 75 PIN:input Video of TV.

NTSC

Decoder

Filter

Comb

Front-end

VIN1

VIN2

PA L

SECAM

NTSC

AGC

VIN3

Tint

Saturation

PA L

Y/G

2 ADC

VIN4

VOUT

Matrix

Processing

Analog

Contrast

V/R

U/B

Front-End

Component

Tint

Saturation

Brightness

FB FB

4 x ADC

RGB/

YCrCb

RGB/

YCrCb

3.Z86229

Addr B us

Row

CSEL

SDO SDA SCK

Serial

SEN

6 4 15 14 1613

SMS

VIN/

Intro

Data Line

VDD

+5V

Sliced

Status Reg

Control Port

Data Bus

FEW

Data CLK

Recove ry

Data

Slicer

Lock

Buffer

Processor

Command

Test Reg

II Lock

Digital

SIG

Slicer

SYNC

MUX

Address

Row

Latch

Display

DOT CLK

DEC

ADDR

RAM

DIV

V Lock

COMP SYNC

ADDR

Decoder

RED

GREEN

Logic

Character

Generator

Latch

Display

FLD

CIR

CHAR

CHAR CLK

OSCO/S

Output

SS CTR

Field

Line &

Control

MSGR

FLD

SLS

SFLD

Control

IDrive

&MUX

BLUE BOX

17 3 2 18

Z86229 only

CKT

POR

V/I

Ref

RREF

Line & Fld

Decodes

Vss(A)

Filter

Loop

LPF

Pin description: 7 PIN:Video input 2 PIN:G output 3 PIN:B output 18 PIN:R output 17 PIN:FB output

Dual

Clamp

Slice Level

Video

CSYNC

CG Lines

Logic

PH1

MSYNC

PH2

HIN

Figure 1. Z86229 Block Diagram

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