LCD TELEVISION
LC-27U18
LC-32U18
America
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
14
15
21
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.
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 fo r 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 (MONO).
The VIDEO signal output from M52760E together with video signals namely AV1 and AV2/S will be
sent to video decoder N601 (TVP5147PFP) 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 of TV output from M52760E will be sent to audio processor N301 (R2S15900SP).
Audio signal L/R of HDMI output from CS4340 together with audio signal L/R of YPbPr and
VGA/DVI will be sent to audio processor N301 (R2S15900SP) after selection by audio switch NA02
(HEF4052).
Audio signal L/R input from AV1A and V2/S will also be sent to N301. After switching selection and
sound effect processing, audio signals sent to N301 will be output as two ways of audio signal. One
way will be output as the audio output of AV OUT, the other way will be sent to audio power amplifier
N401 (TPA3008D2) to obtain amplified audio signal and send to speakers or headphone.
The whole unit is controlled by CPU (N801) MTV412, it can be connected to tuner, TVP5147 and
R2S15900SP etc. through IIC bus; and connected to MST6151 through parallel BUS and control
them.
6
Block diagram
N
N
N
N
N
R
N
N
N
N
N
N
N
AV1-A AV2/S-A
YPbPr-A
VGA/DVI-A L/R
HDMI-A
MONO
A
AV OUT L/R
RF
V
V IIC
VIDEO1
Y/VIDEO2 CCIR656
C 8bit
YPbPr
VGA
HDMI/DVI
L/R
BUS
TUNER
HDMI-A
AUDIO
SW
A02
HEF4052
IF
EEPROM
802
EEPROM
803
SAW
Z102
SAW
Z103
VIDEO
DECORDER
601
TVP5147PFP
DAC
A01
CS4340
MCU
MTV412
801
IF AMP
101(TV board)
M52760E
AUDIO
PROCESSO
301
R2S15900SP
SCALER
A/D D/A
DEINTERLACER
LVDS
HDMI
101(CPU board)
MST6151DA
SDRAM
201
SDRAM
202
AUDIO AMP
401
TPA3008D2
SPEAKER
HEADPHONE
PANEL
7
IC block diagram
g
1. TVP5147
CVBS/
C/Pb
CVBS/
Y
CVBS/
C/Pr
CVBS/Y
VI_1_A
VI_1_B
VI_1_C
VI_2_A
VI_2_B
VI_2_C
VI_3_A
VI_3_B
VI_3_C
VI_4_A
Analog
Front End
Clamping
AGC
2 11-Bit
ADC
Sampling
Clock
Copy
Prot ection
Detector
M
U
X
Timing Proc es sor
With Sync Detector
CVBS/Y
CVBS/Y
C/CbCr
VBI
Data
Processor
Composite and S-Video Processor
Y/C
Separation
5-li ne
Adaptive
Comb
Y
C
Luma
Processing
Chroma
Processin
YCbCr
Interface
Y[9:0]
Output
Formatter
C[9:0]
GPIO
Host
XTAL1
XTAL2
PWDN
AVID
RESETB
DAT ACLK
80: AV OUT
2: TV-V input
7: AV1-V input
9: AV2-V/S-Y input
18: S-C input
29: SDA
28: SCL
40: CLK output
43-47, 50-52: CCIR656 format signal output
4, 5, 20, and 21: 3.3V-A power supply
38, 48, 61: 3.3V-D power supply
11, 25, 76: 1.8V-A power supply
31, 41, 55, and 67: 1.8V-B power supply
FID
GLCO
HS/CS
VS/VBLK
SCL
SDA
8
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
9
3. LA72700
5: SIF input
25: TV sound -R output
26: TV sound- L output
11: SDA
12: SCL
31: +9Vpower supply
10
4. 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
11
5. R2S15900
2: input L of AV1
27: input R of AV1
3: input L of AV2/S
26: input R of AV2/S
4: input L of YPBPR/VGA/HDMI
25: input R of YPBPR/VGA/HDMI
5: input L of TV
24: input R of TV
6: output L of AVOUT
23: output R of AVOUT
11: L output
19: R output
18: SCL
17: SDA
28: +9Vpower supply
12
6. TPA3008
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
13
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
14
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
15
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
16
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
Tota l No . ≤5 ≤2 ≤5 ≤2 ≤3
One single
spot
Two
neighboring
spots
Tota l No . ≤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
17
3. Tr oubleshooting guide
k
f
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
power 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
18
3.2. Raster, but no picture
n
y
d
V
t
f
n
n
Check if the unit butto
and remote control
operation?
yes
no
no
Replace CPU
board
Enter factory-menu,
initialization EEPROM,
then turn off the TV,
turn on again, displa
picture?
Adjust CPU boar
Does display OSD
menu in screen whe
press submenu?
yes
again
yes
Replace
TUNER1
yes
yes
Check if the all
channels have signal?
no
Which is no signal
of channels
TV
Check if 1VPP signal
and noise wave of X2
(PIN 1) in the T
board?
no
Check if outpu
no
IF signal o
TUNER1 (pi
11) is normal?
yes
Check N101
HDMI/VGA/YPRP
Replace
CPU board
19
3.3.no sound
f
N
d
f
N
d
f
N
f
N
Check if PIN15, PIN30
and PIN38 voltage o
401 is normal?
Check power supply
no
yes
Check PIN11 an
PIN19 output wave o
301
no
Check PIN25 an
PIN26 output wave o
101
no
Check PIN7 wave o
101
no
Check PIN11 wave of
TUNER1
no
Replace TUNER1
yes
Replace N401
yes
Replace N301
yes
Replace N101
20
CPU Board(page 1 of 8)
CPU Board(page 2 of 8)
CPU Board (PAGE 3 OF 8)
CPU Board(page 4 of 8)
CPU Board(page 5 of 8)
CPU Board(page 6 of 8)
CPU Board(page 7 of 8)
CPU Board(page 8 of 8)
AV OUT board
key board
TV board
5
4
3
2
1
3
1
GBU806
BCX56-16
Q901
4
1
C971
1UF/50V
D905
2
12
2 3
3
TOP
BAS21
2
AC
AC
3
R922
6.2K ±5%
R931
330K ±5%
R939
330K ±5%
R944
330K ±5%
C913
0.22UF/50V
Q909
BCX56-16
21
R965
5.1K ±5%
1
V+
V-
4
R908
0.22/1W
R923
6.2K ±5%
R932
330K ±5%
R940
330K ±5%
R945
330K ±5%
R950
82K ±5%
R990
470 ±5%
STD-5V
0.47UF/50V
C925
1UF/50V
C905
0.47UF/450V
R909
0.22/1W
J1
VCC1_1 3
C914
22K ±5%
ON_OFF 3
R929
10K ±5%
R953
D901
1N5406RL
1 2
16
SYNC
4
IAC
7
VRMS
10
S-GND
R920
10 ±5%
R924
68K ±5%
15
P-UVLO
7
2
3
ISENSE
9
C919
100PF/50V
C923
2200PF/50V
L904
JCLPQ32-2
E905
6.8UF/35V
+
19
VCC
R966
4.75K ±5%
5
6
8
R913
680 ±5%
R916
4.75K ±5%
CA-OUT
5
R962
22K ±5%
J1
IC902
L4981AD
1
P-GND
8
MULT-OUT
C907
1000PF/50V
R933
4.75K ±5%
2
IPK
SS
12
C921
1UF/50V
1 2
D902
STTA806
ROSC
17
R961
18.2K ±5%
11
VREF
18
6
VA-OUT
COSC
C922
2200PF/50V
R905
R906
R907
1M ±5% 1206
1M ±5% 1206
E903
6.8UF/35V
+
Q904
21
BCX56-16
R930
22 ±5%
R937
22 ±5%
18K ±5%
C915
0.1UF/50V
R957
47K ±5%
12
3
R946
TOP
ISL9R1560G2
Q902
BCX53-16
1 2
R928
2.2 ±5%
1 3
Q905
SPW20N60S5
R941
10K ±5%
C916
1UF/50V
2
1
2
1
150UF/450V
C911
1UF/50V
LFF
GDRV
OVP
VFEED
E901
+
1M ±5% 1206
3
R934
10 ±5%
20
3
14
R954
330K ±5%
13
PFC and STANDBY power supply
KAS200-5S242212
TOP
MUR860
PFC
1
1
R918
360K ±5%
R926
360K ±5%
R935
360K ±5%
R942
360K ±5%
R947
56K ±5%
TEST
PFC 3
R955
150K ±5%
R919
360K ±5%
R927
360K ±5%
R936
360K ±5%
R943
360K ±5%
R948
56K ±5%
R956
24K ±5%
C901
2200PF/4KV
R901
SCK2R55A
T5A/250V
22UF/50V
0.1UF/50V
D908
BAS21
1 3
2
7
VCC
2
4
F901
E902
+
C908
6
N.C
3
IC903
ICE2A180
IC904
PC817A
21
R911
360K ±5%
Drain Drain
4 5
0.47UF/275V
JP?
JUMPER
D13
1
23
R902
1M ±5% 1206
C903
L901 LCM-300
1 2
R959
2.2/1W
R903
MYG-10K-561
R904
1M ±5% 1206
12
D907
1.5KE200A
D910
MURS160T3
1 2
D906
MURS160T3
E909
33UF/100V
21
Q908
BCX56-16
TOP
TL431
L902
5
4 1
8
12
C910
1000PF/2KV
6
7
10 8
9
12
+
4
R507
110 ±5%
3
1
2
3
67
3 2
4.7mH,LXET24-3
R912
? /1W
0.35mm 辅铜
T901
CH4162-C
4
IC917
PC817A
IC905
TL431A
1
2 3
C902
1000PF/4KV
C906
1000PF/4KV
TOP
3
2
1
C
E
B
D911
MURS160T3
1 2
220UF/25V
R951
1K ±5% 1206
25
1
R963
1K ±5%
C924
0.01UF/50V
BCX56-16
BCX53-16
R952
1K ±5% 1206
D913
MBRS140T3
1 2
C917
100PF/50V
1
23
R967
4.75K ±5%
L903
5
4 1
8
VCC1
E906
R506
470 ±5%
67
+
1 2
D903
1N4007
3 2
8mH,LXET24-4
R914
1K ±5%
R917
5.1K ±5%
A
B
B3
+
E904
C909
1000UF/16V
1UF/50V
R949
10K ±5%
L905
LGB-6R9
1 2
E907
+
470UF/16V
ON_OFF_1
R964
110 ±5%
C926
0.1UF/50V
A3
2
R925
360 ±5%
R976
100K ±5%
D904
1N4007
2 1
3
31
Q903
BT169
IC901
PC817A
R938
510 ±5%
STD-5V
R958
1K ±5%
E908
+
220UF/25V
R968
100K ±5%
R969
5.1K ±5%
CN901
3
N
D D
2
NC
1
L
VH-3AW
M1
HOLE_3.5/9.4
1
R910
200K ±5%
R915
200K ±5%
R921
200K ±5%
C C
8
D912
B B
1 2
1N4746A-18V
GND
SoftSFBIsense
1
C918
0.22UF/50V 1206
C920
R960
4700PF/50V
22 ±5%
A A
5
4
3
2
1
5
TOP
BCX56-16
BCX53-16
123
BCE
D D
CN902
24V
1
24V
2
24V
3
RTN
4
RTN
TJC3-4
D935
1N4749A-24V
R553
12V
2
1
7
12V
6
12V
5
4
3
2
1
A
1
TP
1
2
3
4
5
6
7
8
C951
1UF/50V 1206
B
2 3
10 ±5% 1206
STD-5V
ON_OFF 2
1
24V
A
4
1
C940
R504
510 ±5% 1206
C947
0.1UF/50V
R991
510/5W
C953
1UF/50V 1206
IC914
PC817A
CN903
12V
RTN
C C
TJC3-2
CN904
RTN
RTN
STD-5V
RTN
ON_OFF
TJC3-7
B B
CN905
24V
24V
24V
24V
RTN
RTN
RTN
RTN
TJC3-8
A A
1UF/50V
C944
C952
C969
R541
360 ±5%
R988
11K ±5%
R995
R996
10K ±5%
C945
1UF/50V 1206
R513
10K ±5%
1UF/50V
2.2UF/63V
R520
D
1K ±5%
C970
1UF/50V 1206
R521
5.6K ±5% 1206
R546
10K ±5%
3
2
C941
2.2UF/63V
R509
10K ±5%
R514
1K ±5%
5.6K ±5% 1206
D933
LL4148
D934
LL4148
IC908A
84
LM2904
+
-
1UF/50V
R505
510 ±5% 1206
R522
5.6K ±5% 1206
12
12
3
2
1
R501
0.1/1W
R503
0.1/1W
+
-
84
R515
10K ±5%
1UF/50V
R533
2K ±5%
R547
2K ±5%
C939
0.1UF/50V
IC910A
LM2904
1
R517 0.1/1W
R519 0.1/1W
R524 0.1/1W
C958
IC915A
LM2904
1
IC915B
LM2904
7
R992
10K ±5%
STD-5V
84
+
-
84
+
-
3
2
5
6
R993
360 ±5%
+
E914
680UF/25V
1UF/50V
C948
+
E919
680UF/35V
R531
1K ±5% 1206
STD-5V
C967
4
C950
0.1UF/50V
C938
L908
LBG-1R7
1UF/50V
L909
LBG-1R7
R548
1.2K ±5%
1UF/50V
D931
1N4743A-13V
R512
360 ±5%
D925
1N4733A-5.1V
12
+
12
R989
3.6K ±5%
R994
3.6K ±5%
+
E916
E915
680UF/25V
680UF/25V
R510 3.6K ±5%
R511 3.6K ±5%
1
2 3
IC911
PC817A
+
+
E920
680UF/35V
R534
27K ±5%
C961
0.1UF/50V
R544
27K ±5%
C966
0.1UF/50V
E921
680UF/35V
4
R532
6.2K ±5%
R535
1.3K ±5%
R545
1.2K ±5%
R540
13K ±5%
A
B
3
12V_1
IC909
PC817A
D1 2
C960
1UF/50V
R542
24V_1
33K ±5%
D1 2
2 3
1
2 4
1
4
R537
20K ±5%
R543
2.4K ±5%
L907
KH32XH-L907
B
A
R518
2.2K ±5%
1UF/50V
C957
R538
1K ±5%
12V_2
5
24V_2
63
R997
220 ±5% 1206
0.22UF/50V
C962
R539
2.2K ±5%
5
1
220 ±5% 1206
R552
R551
R998
220 ±5% 1206
C943
100PF/50V 1206
R525
1K ±5%
R530
1K ±5%
C955
0.01UF/50V
C965
1000PF/50V
IC916
TL431ACLP
1
2 3
2
46
23
2
R987
220 ±5% 1206
220 ±5% 1206
2
C937
100PF/50V 1206
2
R999
220 ±5% 1206
2
VCC1_12
1
2 3
IC912
PC817A
VCC1_1
4
PFC2
3
D919
MBR20100CT
1
3
D922
MBR20100CT
1
3
D926
MBR20150CT
1
3
D927
MBR20150CT
1
1
HS501
LHS-80
0.1UF/50V
R516
10 ±5%
C954
T3.15A/250V MRT1
1
2
5
8
8.2K ±5%
R529
C956
0.1UF/50V
F902
T902
KH32XH-T902
2
1
3
6
7
5
8
4
C968
COMP
VFB
GROUND
VREF
4
1UF/50V
22UF/50V
RT/CT
C963
1000PF/50V
C930
0.1UF/630V
12
9
10
11
+
E918
IC913
7
UC3845
VI
OUTPUT
3
C959
100PF/50V
1
HS901
LHS-80
L?
?
12
D917 1N4746A-18V
1 2
R984 10K ±5%
R986 10K ±5%
1 2
D921 LL4148
D924
MURS160T3
D928
1 2
MURS160T3
C946
100PF/2KV
R523
4.7 ±5%
6
1 2
1000PF/50V
D932
1N4746A-18V
ISENSE
C964
KAS200-5S242212
HS902
LHS-80
1
1
SPP11N60C2
2
5 1
T903
1 2
JCBD19-23
R502
R508
1 2
D929
MURS160T3
C949
0.22UF/50V 1206
Q907
SPP11N60C2
1 3
10K ±5%
R526
R527
HS903
LHS-35
Q906
13
220/1W
220/1W
2
2.2/1W
R536
1K ±5%
1
HS9001
4.7 ±5%
0.22UF/50V 1206
4
7
HS502
LHS-80
0.5/1W
R528
R982
C936
1
C942
HS9001
HS503
LHS-80
1
4700PF/250V
main 24V circuit
5
4
3
2
1
IR board
APPENDIX-B: Exploded View(LC-27U18)
PART LIST OF EXPLODED VIEW(LC-27U18)
No. PART NO. DESCRIPTIONRE
1 742-30091-00 Line clasp
2 615-10559-00 Stand assy
3 808-10829-00 Bottom connecting cover
4 808-10835-00 Rear cabinet(left)
5 870-10276-00 Connecting piece of speaker box
6 808-10837-00 Side decorate cover
7 808-10836-00 transfer axis cover
8 808-10812-00 Power lead cover
9 615-10545-00 Mounting assy
10 808-1A841-00 AV baffle (left)
11 Digital processing board assy
12 808-10840-00 Button cover
13 743-1B180-00 Button decorate piece
14 Button board assy
15 615-1A526-00 LCD screen fixed mount assy
16 Screen
17 808-2A330-202 ACTIVE panel
18 780-X18W0-00 Front cover
19 Power board assy
20 Sound trans-connecting assy
21 808-1A842-00 AV baffle (right)
22 Video processing board assy
23 Indicator assy
24 870-3A183-00 USB bracket
25 700-60255-00 LED column
26 Infrared receiving board assy
27 870-10285-00 Power supply socketbracket
28 780-X18RH-00 Rear cabinet
29 615-20464-00 Bottom speaker assy
APPENDIX-B: Exploded View(LC-32U18)
PART LIST OF EXPLODED VIEW(LC-32U18)
No. PART NO. DESCRIPTIONRE
1 808-20332-202 ACTIVE panel
2 780-G18L0-AW1 Front cover
3 870-30190-00 LED columnbracket
4 360-30042-00 Power switch
5 700-60256-00 LED column
6 700-60255-100 LED column
7 Infrared receiving board assy
8 Screen
9 615-10562-00 LCD screen fixed mount assy
10 Power board assy
11 Sound trans-connecting assy
12 870-10219-00 Mounting holder
13 808-10867-AF0 Rear cabinet (USB)
14 808-10865-AF0 Rear cabinet (right)
15 780-G18L1-AF1 Rear cabinet
16 808-10812-AF0 Power lead cover
17 615-20482-00 Bottom speaker assy
18 615-10578-00 Stand assy
19 808-10863-AF0 Speaker connecting cover
20 808-10866-AF0 Rear cabinet (bottom )
21 808-10864-AF0 Rear cabinet (left)
22 808-10859-AF0 decorate cover (leftright)
23 Button board assy
24 870-10218-00 Mounting holder (horizontal )
25 870-1A133-00A Mounting holder (middle )
26 CPU board assy
27 Video processing board assy
603-L27U180-10
603-L32U18X-XX
Ver.1.0
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