Xoceco LC-27U26 Schematic

LCD TELEVISION

LC-27U26

CONTENTS

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

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

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

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

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

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

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

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

APPENDIX-A: Main assembly list

APPENDIX-B: Exploded views

1

3

6

7

8

15
16
22

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

1

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
dagame.

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.

2

Alignment instructions

r

1. Test equipment

PM5518 (video signal generator)
K-7253 (VGA signal generator)
CA210 (white balancer)

2 Alignment flow-chart

The alignment flow-chart is shown as fig-1

Check DDC, HDCP KEY and CPU

Factory initialization setup

IF channel voltage of TV and AGC voltage adjustment

Support format of VGA pre-set

Adjustment for sub-brightness and white balance of VGA/HDMI (colo

temperature 6500k, 9300k and 12000k)

Adjustment for sub-brightness and white balance of YPbPr/YcbCr channel

Adjustment for sub-brightness and white balance of VIDEO channel

Fig-1 adjustment flow-chart

3 Unit adjustments

Connect digital board, CPU board and analog board according to wiring diagram, connect with
power and observe the display.
Method for entering factory menu: press “SLP”, “DSP”, “MENU” and “DSP” in turn to enter factory
menu; press “CH+” and “CH-” to select adjustment items and press “VOL+” and “VOL-” to adjust
value items, press “MENU” to exit.
Note: the white balance adjustment should be done under “nature” picture mode.

3.1 Initialization
Enter factory menu, select “Factory settings” sub-menu, and adjustment for items of table1.

Table1 sub-menu adjustment

Items Range Introduce

PW on LOGO ON/OFF Display 5s LOGO of turn on the TV

NO Sig LOGO ON/OFF If display LOGO in no signal

Black Screen BLUE/BLACK If display blue screen and white noise wave in no signal, setting “BLUE”

Preset ex-factory

3

MLK 120-159 Adjustment for clock frequency (MHz) of memorizer, setting “145”.

PIP Size Middle/Large Select two component of PIP: “SMALL AND MIDDLE” and “SMALL AND BIG”,

setting “MIDDLE”.

init EEprom Start? Eeprom Initialization (adjustment for EEprom data)

3.2 Adjustment for AFT voltage and AGC voltage of IF channel in TV
Input frequency for 45.75MHz and IF signal for 80dBV of TP1, adjust L107 to value 2.4v of TP2;
when increase 0.10MHz of TP1 input signal, the TP2 value 1.0v at least; but decrease

0.10MHz of TP1 input signal, the TP2 value 4.0v at least.

3.3 VGA/DVI channel adjustment

3.3.1 Preset VGA channel mode

Input VGA signal (PATTERN: CROSS) of VG-849 or VG-848, select PROG850(640*400/85Hz),
auto adjustment until the screen is filled with picture. Use the same method to do auto adjustment
for the following items:

PROG851(640*480/72 Hz) PROG852(640*480/75 Hz) PROG853(800*600/56 Hz)

PROG854(800*600/60 Hz) PROG855(800*600/72 Hz) PROG856(1024*768/60 Hz)

PROG857(1024*768/70 Hz) PROG858(1280*768/75 Hz) PROG888(800*600/75 Hz)

PROG915(1152*870/75 Hz) PROG915 (1280*1024/60Hz)

3.3.2 Sub-brightness and White balance adjustment VGA/HDMI channel

a. Input VG-849 or VG-848 signal of VGA: PROG852(640* 480/75Hz) and eighth level gray-scale
signal of PATTERN. Use color analyzer CA210 to adjust sub-brightness and white balance.
b. Enter submenu of COLOR TEMP., Select 9300k of color temperature, set auto value of R, G and
B to 50. Enter submenu of white balance, preset value of offset_R, offset_G and offset_B to 125,
and preset value of gain-R, gain-G and gain-B to 100. Adjustment for brightness let the second level
brightness be 3nit at least.
c. Fixed value of offset_B, adjust offset_R and offset_G, let the color coordinate of the second level
be 285 and 293 and its brightness be 4-5nit more or less (it can not 3.5nit at least). Fixed value of
gain_B, adjust gain_R, gain_G and gain_B, let the color coordinate of seventh level be 285 and 293.
Adjustment offset_R, offset_G, offset_B, gain_R, gain_G and gain_B repeatedly until the value of
the two levels gray-scale be 285 and 293.
d. Select 6500k of color temperature, set auto value of R, G and B to 50. Fixed value of B to 50,
adjust R and G, let the color coordinate of the sixth level be 313 and 329. Adjust R and G repeatedly
until the color coordinate value to 313 and 329.
e. Select 12000k of color temperature, set auto value of R, G and B to 50. Fixed value of B to 50,
adjust R and G, let the color coordinate of the sixth level be 270 and 283. Adjust R and G repeatedly
until the color coordinate value to 270 and 283.
f. Input PROG852(640*480/75Hz) and the eighth level gray-scale of PATTERN signal of VG-849 to
HDMI, repeatedly the b-e course. In the HDMI channel, preset value of offset_R, offset_G and
offset_B to 15, preset value of gain_R, gain_G and gain_B to 25.

3.4 Adjustment for sub-brightness and white balance of YPbPr channel

a. Connect YPbPr signal of VG-849 and VG-848 to YPbPr terminal, input color signal of
PROG973(1080i)PATTERN964. Select AUTOTUNE item, wait for it displays “OK”. NOTE: Don’t
select AUTOTUNE item in other state.

4

b. Switch YPbPR signal of VG-849 and VG-848 output to the eighth gray-scale signal of
PROG973(1080i)PATTERN964. prset value of offset_R, offset_G and offset_B to 15 and gain-R,
gain-G and gain-B to 25. adjust brightness, let second bright to 3nit at least.
c. Fixed value of offset_B, adjust offset_R and offset_G, let the color coordinate of the second level
be 285 and 293 and its brightness be 4-5nit more or less (it can not 3.5nit at least). Fixed value of
gain_B to 25, adjust gain_R, gain_G and gain_B, let the color coordinate of seventh level be 285
and 293. Adjustment offset_R, offset_G, gain_R and gain_G repeatedly until the value of the two
levels gray-scale be fixed.
d. Input PROG977(720p), PROG978(480p) and PROG968(480i) mode for eighth level gray-scale
signal, let the color coordinate of the second level and the seventh level 285 and 293.

3.5 VIDEO channel adjustment (TV/VIDEO/S-VIDEO)

a. Connect color bar signal of AV (PM5518, NTSC , eight level gray-scale signal) to VIDEO1
terminal, enter factory menu, preset value of offset_R, offset_G and offset_B to 15 and gain-R,
gain-G and gain-B to 25, adjust brightness, let second bright to 3nit at least.
b. Fixed value of offset-B to 15, adjust offset_R and offset_G, let the color coordinate of the second
level be 285 and 293 and its brightness be 4-5nit more or less (it can not 3.5nit at least). Fixed value
of gain_B to 25, adjust gain_R, gain_G and gain_B, let the color coordinate of seventh level be 285
and 293. Adjustment offset_R, offset_G, gain_R and gain_G repeatedly until the value of the two
levels gray-scale be fixed.

4 Performance check

4.1 TV function

Enter searching menu → auto search, connect RF-TV terminal with central signal source and check
if there are channels be skipped

4.2 AV/S, YpbPr terminals

Input AV/S, HD signal, check if it is normal.

4.3 VGA terminal

Insert VGA terminal, input VGA format signal of 640 X 480@60 Hz, check if the display is normal. If
interference exists, press the auto adjusts button on remote control again and check if it is normal.

4.4 HDMI terminal

Insert HDMI terminal, input signal of 640 X 480@60 Hz signal and check if the display is normal.

4.5 check sound channel

Check the speaker and headphone of each channel.

4.6 presetting before ex-factory

Item Setting Item Setting Item Setting

Picture mode NATURE OSD language English CCD OFF

Sound mode NORMAL HALFTONE 50 STEREO ON

N/R WEAK DURATION 30 VGA/HDMI NORMAL

SCREEN FULL MAG.C ON ANTENNA CATV

5

Working principle analysis of the unit

The RF signal received by antenna will be sent to tuner, then IF signal will be obtained through high
amplifier and mixed frequency, through pre-intermediate amplified by V104, then it will be sent to
acoustic surface-wave Z103 to do IF filter and get better IF characteristics, then it will be sent to TV
board N101 (M52760E) to do intermediate amplification, phase-locked loop VCO and synchronous
wave detection to get composite video signal VIDEO; after pre-intermediate amplification IF will also
be sent to acoustic surface-wave Z102 to do filter at the same time, then it will be sent to N101 to do
intermediate amplification and demodulate audio signal (SIF).
The VIDEO signal output from M52760E together with video signals namely AV1 and AV2/S will be
sent to video decoder N601 (TVP5160) to de video selection, clamp, A/D transformation,
comb-shaped filter and color decode, then one way will output as video output of AV OUT, one way
will output 8bit CCIR656 format signal and CLK signal, then it will be sent to the main chip N101
(MST6151) of CPU; YpbPr, VGA and HDMI signals will also be sent to N101 (DVI interface can be
connected to HDMI interface through the use of a passive cable converter).The main chip
N101(MST6151) a multifunctional large-scale specified integrated circuit board, it has many kinds of
function such as A/D and D/A transformation, interleaved/ line-by-line processing, mode
transformation, low voltage differential output processing etc., then output four couples differential
signal and one couple clock signal.
The signals input from HDMI to MST6151 include audio signal, after processing in MST6151, it will
be sent to NA01 (CS4340) to do D/A transformation and then output audio signal L/R of HDMI.

Audio signal L/R of HDMI output from CS4340 output together with audio signal L/R of YPbPr and
VGA/DVI will be sent to audio processor N801 (MSP3425G) after selection by audio switch NA02
(HEF4052); L/R signal of AV1 and AV2/S via selected switch N701(HEF4052) will also be sent to
N801,and SIF of TV output from M52760E send to N801 too. In MSP3425G, the demodulated L/R
of SIF and the input L/R from other two ways, via selected switch and processing sound, then
output signal, one way sound output for AV OUT, other way send to N401(TPA3008D2) of sound
amplifier, via amplify for sound signal to speaker.
The whole unit is controlled by CPU (N801) MM502, it can be connected to tuner, TVP5160 and
MSP3425G etc. through IIC bus; and connected to MST6151 through parallel BUS and control
them.

6

Block diagram

N

N

N

N

N

N

N

N

N

N

N

N

N

HDMI-A AV-A OUT

YPbPr-A

VGA/DVI-A L/R

L/R

AV 1 - A

AV 2 / S - A

L/R

SIF

RF

V IIC

AV-V OUT

VIDEO1 CCIR656

Y/VIDEO2 8bit

C

YPbPr

VGA

HDMI/DVI

L/R

BUS

L/R

TUNER

HDMI-A

AUDIO

SW

A02

HEF4052

AUDIO

SW

701

HEF4052

IF

EEPROM

802

EEPROM

803

SAW

Z102

SAW

Z103

VIDEO

DECORDER

601

TVP5160

DAC

A01

CS4340

MCU

801

MM502

AUDIO

PROCESSOR

801

MSP3425G

IF AMP

101(TV board)

M52760E

SCALER

A/D D/A

DEINTERLACER

LVDS

HDMI

101(CPU board)

MST6151DA

SDRAM

201

SDRAM

202

AUDIO AMP

401

TPA3008D2

SPEAKER

PANEL

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IC block diagram

1. TVP5160

The TVP5160 device is a high quality, digital video decoder that digitizes and decodes all popular
baseand analog video formats into digital component video. The TVP5160 decoder supports the
A/D conversion of component YPbPr and RGB (SCART) signals, as well as the A/D conversion and
decoding of NTSC, PAL, and SECAM composite and S-Video into component YCbCr. Additionally,
component progressive signals can be digitized. The chip includes two 11-bit, 60-MSPS, A/D
converters (ADCs). Prior to each ADC, each analog channel contains an analog circuit, which
clamps the input to a reference voltage and applies a programmable gain and offset. A total of 12
video input terminals can be configured to a combination of YPbPr, RGB, CVBS, and S-Video video
inputs.
Progressive component signals are sampled at 2x clock frequency (54 MHz) and are then
decimated to the1x rate. In SCART mode the component inputs and the CVBS inputs are sampled
at 54 MHz alternately, then decimated to the 1x rate. Composite or S-Video signals are sampled at
4x the ITU-R BT.601 clock frequency (54 MHz), line-locked for correct pixel alignment, and are then
decimated to the 1x rate. CVBS decoding utilizes advanced 3D Y/C filtering and 2-dimensional
complementary 5-line adaptive comb filtering for both the luma and chroma data paths to reduce
both cross-luma and cross-chroma artifacts. 3D Y/C color separation may be used on both PAL and
NTSC video signals. A chroma trap filter is also available. On CVBS and Y/C inputs, the user can
control video characteristics such as hue, contrast, brightness, and saturation via an I2C host port
interface. Furthermore, luma peaking with programmable gain is included, as well as a patented
color transient improvement (CTI) circuit. Attenuation at higher frequencies or asymmetrical color
subcarrier sidebands are compensated using the IF compensation block. Frame adaptive noise
reduction may be applied to reduce temporal noise on CVBS, S-Video, or component inputs.
3D noise reduction and 3D Y/C separation may be used at the same time or independently.
The TVP5160 decoder utilizes Texas Instruments’ patented technology for locking to weak, noisy,
or unstable signals and can auto-detect between broadcast quality and VCR-style (nonstandard)
video sources.
The TVP5160 decoder generates synchronization, blanking, field, active video window, horizontal
and vertical syncs, clock, genlock (for downstream video encoder synchronization), host CPU
interrupt and programmable logic I/O signals, in addition to digital video outputs.
The TVP5160 decoder includes methods for advanced vertical blanking interval (VBI) data retrieval.
The VBI data processor (VDP) slices and performs error checking on teletext, closed caption, and
other VBI data. A built-in FIFO stores up to 11 lines of teletext data, and, with proper host port
synchronization, full-screen teletext retrieval is possible. The TVP5160 decoder can pass through
the output formatter 2x sampled raw Luma data for host-based VBI processing.
Digital RGB overlay can be synchronously switched with any video input, with all signals being
oversampled at 4x the pixel rate.

8

9

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2. M52760SP

The M52760SP is IF signal-processing IC for VCRs and TVs. It enable the PLL detection system
despite size as small as that of conventional quasi-synchronous VIF/SIF detector, IF/RF AGC, SIF
limiter, FM detector and EQ AMP.
FEATURES

•Video detection output is 2VP-P. It has built-in EQ AMP.

•The package is a 20-pin shrink-DIP, suitable for space saving.

•The video detector uses PLL for full synchronous detection circuit. It produces excellent

characteristics of DG, DP; 920kHz beat, and cross color.

•Dynamic AGC realizes high-speed response with only single filter.

•Video IF and sound IF signal processings are separated from each other. VCO output is used to

obtain intercarrier. This PLL-SPLIT method provide good sound sensitivity and reduces buzz.

•As AFT output voltage uses the APC output voltage, VCO coil is not used.

•Audio FM demodulation uses PLL system, so it has wide frequency range with no external parts

and no adjustment.

•QIF AMP has a fixed gain, and good characteristic for NICAM.

2: AFT
3: AGC
4, 5: picture If input
7: sound IF input
13: SIF output
10: mono sound output
18: TV- VIDEO output
14, 17: +5V-1 power supply

11

3. MST6151

pins function:

207, 208: HDMI-R input
2, 3: HDMI-G input
5, 6: HDMI-B input
8, 9: HDMI-CLK input
14: HDMI-SDA
15: HDMI-SCL
20, 21: VGA-B input
22: VGA-G input
23, 24: VGA-G input
25, 26: VGA-R input
18: VGA H-sync input
19: VGA V-sync input
27, 28: PB input
29, 30: Y input
31: HDMI-G input
32, 33: PR input
54-61: CCIR656 format signal input
53: CLK input
164-171, 174: 4 difference signal output
160, 161: 1 clock signal output
188-191: HDMI sound output
200: PWW (brightness control switch) output
72-75: BUS (parallel communication signal)
49, 131, 195: 1.8V power supply
4,17,12,109,204,66,102: 3.3V power supply

12

4. MSP3425G

13

5. TPA3008

FUNCTIONAL BLOCK DIAGRAM

1: MUTE
3: R input
5: L input
20, 17: L input
41, 44: R input
15, 23, 33, 39, and 47: +18V power supply

14

Wiring diagram

A

Panel

CPU board (main board)

Power supply board

X903 X904

X7

X10

X1

X8

X3

X2

Voutboard

TV board

X6

X2

Speaker

15

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

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.

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

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

When playing VHS picture search

tape, there are lines at the top or

bottom of the picture.

 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.

 Of if it has received the right video signal.

 Check if the sound volume is set to minimum.

 Make sure the earphone is not connected.

 Check if the cable connection is loose.

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

Category Criteria

One single

spot

Bright

spot

Dark

spots

Total defected point ≤8 ≤7 ≤5 ≤4 /

Two

neighboring

spots

Tot al N o . ≤5 ≤2 ≤5 ≤2 ≤3

One single

spot

Two

neighboring

spots

Tot al N o . ≤6 ≤7 ≤5 ≤4 ≤10

15" 20" 22" 30" 40" 15" 20" 22" 30" 40"

≤5 ≤2 ≤5 ≤2 ≤3

≤2 ≤1 ≤2 ≤1 ≤1

≤6 ≤7 ≤5 ≤4 ≤10

≤2 ≤2 ≤2 ≤1 ≤5

Notes:

1. Definition of defected point (bright spot, dark spot): It is identified as a defected point if its area

exceeds 1/2 of a single picture element (R, G, B).

2. Definition of bright spot: It is identified as a bright spot if it is bright in the state of dark field and its

bright size remains unchanged

3. Definition of dark spot: It is identified as a dark spot if it is dark in the state of white field and its

dark size remains unchanged

4. Definition of two neighboring points: Defects of a group of picture elements (RB, RG, GB).

Quantity allowed Distance between two spots

≥15mm

≥15mm

≥10mm ≥5mm

18

3. Troubleshooting guide

k

f

p

n

3.1. No raster

Turn-on power supply, chec

if the red indicator is light in

the STANDBY?

no

Check if PIN8(5V) of CPU

board is normal?

no

Check STANDBY circuit o

ower supply board

Press POWER button in the

unit button and sensor control,

check the indicator.

Check if the PIN12 of X503 in

CPU board is high-level?

Check back light board

no

Replace N801

yes

red

blue

yes

no

Check if the PIN7 of X501 i

CPU board is high-level?

yes

Check power supply board

19

3.2. Raster, but no picture

y

p

d

V

f

p

Check if the unit button

and remote control

operation?

yes

no

no

Replace CPU

board

Enter factory-menu,

initialization EEPROM,

then turn off the TV,

turn on again, displa

icture?

Adjust CPU boar

Does display OSD

menu in screen when

ress submenu?

yes

again

yes

Replace

TUNER1

yes

yes

Check if the all

channels have signal?

Which is no signal

Check if 1VPP signal

and noise wave of X2

(PIN 1) in the T

board?

no

no

of channels

TV

no

Check if output

IF signal o

TUNER1 (pin

11) is normal?

yes

Check N101

HDMI/VGA/YPRP

Replace

CPU board

20

3.3.no sound

f

N

f

N

Check if PIN15, PIN30

and PIN38 voltage o

401 is normal?

Check power supply

no

yes

Check PIN26 and

PIN27 output wave o

801

no

Check PIN13 output

wave of N101

no

Check PIN5 wave of

Z102

no

Check PIN11 wave of

TUNER1

no

Replace TUNER1

yes

Replace N401

yes

Replace N801

yes

Replace N101

21

AV OUT board

key board

POWER BOARD

667-L27U25-20

IR board

MCU

CPU board (page1 of 8)

LVDS&BK

CPU board (page2 of 8)

POWER

CPU board (page3 of 8)

SDRAM

CPU board (page4 of 8)

TVP5160

CPU board (page5 of 8)

YPbPr&AUDIO SWITCH

CPU board (page6 of 8)

CPU board (page7 of 8)

CPU board (page8 of 8)

video board (page1 of 2)

video board (page1 of 2)

APPENDIX-A: Main assembly 9227LU2614

NAME NO.

Video processing board

CPU board

Audio covert board
Key board
IR board
Power board
Remote control
Panel

6LU0154010

6LU0065610

6LU0081510
6LU0160510
6LU01609A0
6LU0082010
6010R03202
5203275501

MAIN COMPONENT AND IT'S NO.

N101
N801
N401

N101
N601
NA01
N801

RC-R32M-0B
V270B1-L01

M52760 (5265276001)
MSP3425G (5273425001)
TPA3008D2 (5273008001)

MST6151DA (5276151001)
TVP5160 (5275160001)
CS4340 (5274340001)
MM502 (5270502001)

APPENDIX: Exploded view (LC-27X26)

PART LIST OF EXPLODED VIEW (LC-27X26)

NO. PART NO. DESCRIPTION

1 5QX26W009D Front cabinet
2 Screen
3 58A0039100 LCD screen frame (top)
4 58A003930A LCD screen frame upright1
5 58A0039500 LCD screen connection bracket1
6 574018901B Power board frame
7 5740188010 Main board frame
8 Power board assy

9 CPU board assy
10 58A0039700 Wall mount connection piece
11 5830D9681B AV baffle (left)
12 5830D96910 AV baffle (right)
13 Key board assy
14 5HX26WH01C Back cabinet
15 5830098110 Back cabinet cover (right)
16 5830098010 Back cabinet cover (left)
17 5830098210 Rotor cover
18 6151067520 Stand assy
19 6170575000 Speaker assy
20 Analog board assy
21 trans-connect board assy
22 5810046800 Connecting piece of speaker box
23 IR receice board
24 5830097010 AV baffle (bottom )
25 Active Decorative piece
26 58A0039200 LCD screen frame(bottom )
27 58A0039400 LCD screen frame upright2
28 58A0039600 LCD screen connection bracket2
29 58B0A24110 Main switch bracket

9227LU2614
Ver.1.0