Text preview for : LC-32HU26.pdf part of . Various LC-32HU26 . Various CHINA TV LCD LC-32HU26.pdf



Back to : LC-32HU26.pdf | Home

LCD TELEVISION




LC-32HU26
CONTENTS


Safety instructions...................................................................................... 1
Adjustment instruction .............................................................................. 3
working principle analysis........................................................................... 6
block diagram........................................................................................... 7
IC block diagram.........................................................................................8
Wiring diagram ......................................................................................... 14
Troubleshooting guide ................................................................................ 15
Schematic diagram......................................................................................21
APPENDIX-A: Assembly list
APPENDIX-B: Exploded view
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
damage.
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
1. Test equipment
PM5518 (video signal generator)
VG-849 (VGA and HDMI signal generator)
CA210 (white balancer)
2 Alignment flow-chart
The alignment flow-chart is shown as fig-1

Check DDC, HDCP KEY, FLASH and POWER control IC



Factory initialization setup


IF channel AFT voltage of TV and AGC voltage


VGA, YPbPr ADC correction


White balance adjustment


Performance check


Preset ex-factory


Fig-1 adjustment flow-chart
3 Unit adjustments
Connect all the boards according to wiring diagram, connect with power and observe the display.
Method for entering factory menu: press "INPUT", "2", "5", "8" and "0" 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" continuously to exit.
Method for software upgrading: enter factory menu and select "OPTION", set ISP to 1 or insert
jump wire J1, then you can upgrade on line. After upgrade, set ISP back to 0 or pull out jump wire
J1.
3.1 Initialization
Enter factory menu, select "OPTION" and "HOTEL OPTION" sub-menu, adjustment of items to see
table1.
Table1 sub-menu adjustment
Items Preset Introduce
HOTEL 0 1: HOTEL OPTION of factory menu is optional
0: HOTEL OPTION of factory menu is not optional
LOGO 1 1: display LOGO in no signal or turn on
0: no LOGO display



3
ADC PRESCALE 00A Software auto preset according the power consumption
SIF PRESCALE 000 Software auto preset according the power consumption
BACK LIGHT 13 Software auto preset according the screen
ALL COLOR 1 1: white balance of each channel auto offset based on the HDMI white
balance
0: white balance of each channel adjust the offset base separately
NO STANDY 00 01: turn on 00: memory function of turn on 10: standby
INIT VOLUME 0-100 Volume when turn on
INIT CHANNEL 1-200 Channel when turn on
INIT SRC Program source Input Source when turn on
EEPROM-MEMORAY > EEPROM Initialization (operate when EEPROM data chaos)
RECALL


3.2 Adjustment for AFT voltage and AGC voltage of IF channel in TV
3.2.1 IF AFT adjustment
Enter factory menu, set IF VCO to 1, or press "INPUT", "2", "5", "8", "1" to enter VCO
adjustment mode, disconnect J2, adjust LZ100 to value 2.5V of TP5(B face), then wed J2.
3.2.2 IF AGC adjustment
Input 184.25MHz RF signal of 60DBuv from RF terminal for china, and 175.25MHz for
America, adjust RZ133 to value 2V of TP1(B face) and there should be no obvious snowy picture.
Increase the signal to 90DBVuv and it should be display normally and no obvious noise.
3.3 White balance adjustment
3.3.1 HDMI white balance correct
a. Input VG-848 signal to HDMI: TIMING854(800*600/60Hz) 8 level gray scale of PAT920,
adjust the balance with CA210.
b. Enter COLOR TEMP sub menu and select color temperature of standard(9300K)
c. Fixed B OFF, adjust R OFF, G OFF to let the color coordinate of the second level be
283,297(CPT panel) and the brightness be 3nit ~10nit or so; Fixed B GAIN, adjust R GAIN, G GAIN
to let the color coordinate of the seventh level be 283,297(CPT panel). Repeat adjust R OFF, G OFF,
R GAIN and G GAIN, until the two color coordinate of the level gray scale be 283,297(CPT panel).
3.3.2 VGA/YPbPr white balance check and correct
a. Connect VG-848 signal of VGA to VGA terminal and input TIMING854(800*600/60HZ)
(PATTERN:CROSS), and auto adjust to full screen then input PAT948 black/white signal, enter
submenu of ADC ADJ, select AUTOTUNE and wait for OK display. Input PAT920(8 gray levels),
check if the white balance is normal, if not, set ALL COLOR to 0 and fine adjust according the
method of 3.3.2
b. connect VG-848 signal of YPbPr to YPbPr terminal and input TIMING972(1080I/60Hz)
PAT908 color bar(include back/white bar), enter submenu of ADC ADJ, select AUTOTUNE and wait
for OK displaly. Input PAT920(8 gray levels), check if the white balance is normal, if not, set ALL
COLOR to 0 and fine adjust according the method of 3.3.2
c. Input AV signal(PM5518, 8 gray levels PAL for China and NTSC for America) to VIDEO 1
terminal, check if the white balance is normal, if not, set ALL COLOR to 0 and fine adjust according
the method of 3.3.2.
Note: it can't set back to 1 once ALL COLOR changes to 0.

4
4 Performance check
4.1 TV function
Enter searching menu auto search, connect RF-TV terminal with central signal source and check
if the picture is normal, if there are channels be skipped. Check CCD and V-CHIP function for
America.
4.2 AV/S, YPbPr terminals
Input AV/S, YPbPr/YCbCr HD signal, check if it is normal.
4.3 VGA terminal
Insert VGA terminal, input VGA format signal of 640X480@60 Hz and check if the display is normal.
4.4 HDMI terminal
Insert HDMI terminal, input 640X480@60Hz signal, check if the display is normal. Check HDCP
function.
4.5 check sound channel
Check the speaker and earphone of each channel.
4.6 RS232 terminal
Put the earphone line into COM terminal, check the long-distance control function with special test
software.
4.7 other function check
Check the turn on/turn off timer, asleep timer, picture/sound mode, OSD, freeze/mute,
stereo/SAP(for America), ect.
4.6 presetting before ex-factory

Item Setting Item Setting Item Setting
PICTURE MODE NAUTRAL OSD English/Chinese
COLOR MODE DK HALFTONE 50
SOUND MODE NEWS DURATION 15 VGA/HDMI STANDARD
NR WEAK ANTENNA CATV
ZOOM FULL Turn off channel TV




5
Working principle analysis of the unit
The RF signal received by antenna will be sent to tuner TUN1, then IF signal will be obtained
through high amplifier and mixed frequency, through pre-intermediate amplified by VZ100, then it
will be sent to acoustic surface-wave ZZ101 to do IF filter and get better IF characteristics, then it
will be sent to NZ100 (R2S1040) to do intermediate amplification, phase-locked loop VCO and
synchronous wave detection to get video signal TV-CVBS; after pre-intermediate amplification IF
will also be sent to acoustic surface-wave ZZ100 to do filter at the same time, then it will be sent to
NZ100 to do intermediate amplification and output the second sound intermediate frequency signal
(TV-SIF).
The TV-CVBS signal output from R2S1040 together with TV-SIF will be sent to main IC NS4
(MST9U88L). Video signal of AV1, AV2, S-VIDEO, YPbPr1 and YPbPr2 will also be sent to
MST9U88L; while the audio signal of them via audio switch NW200(HEF4052BT) selection to
MST9U88L (AV1 and S-VIDEO share one audio port). Video and audio signal of VGA, HDMI will be
sent to MST9U88L, too.
The main IC NS4(MST9U88L) is a high performance and fully integrated IC, which can realize
HDMI interface processing, video demodulating, video switch selection, A/D and D/A conversion,
interlace/de-interlace processing, modes conversion, OSD and low-voltage differential output, ect.
And it also has functions of audio selection, processing and MCU.
The video signal via MST9U88L processing, output 4 pairs differential signal and 1 pair clock
signal for LCD panel display. Video signal of AV1, AV2, S-VIDEO and TV via initial selection and
processing, output video signal of AV-OUT, after double video amplifying, it will be sent to AV-OUT.
Audio signal via MST9U88L processing, output two ways; one way will be sent to sound
amplifier NA6(MP7722DF) amplifying, then sent to speaker. At the same time, it also sent to
earphone sound amplifier N350(BH3547F), after amplifying then sent to earphone. Another way will
be sent to D/A converter NS6(CS4344) through I2S bus, convert to analog sound signal L/R output
through AV-OUT.




6
Block diagram
KEY


TUNER EEPROM HDCP Serial flash DDR Power I/O port
KEY controlMeg8
EDID

HDMI

Pre-IF PC

EDID
HD1/HD2

IF AV1/AV2/ P

A
TV-Video
MST9X88L N

E
L/R-DVI/PC
L


TV-SIF


L/R-MUX

I2S
L/R-HD1 DAC 2 multiple D class amplifier
CS4344 video amplify Earphone amplifier MPS7722
L/R-HD2
4052
L/R-AV1
L/R-OUT VIDEO-OUT
AV OUT Earphone Speaker
L/RAV2


7
IC block diagram
1. MST9U88L
The MST9U88L is a high performance and fully integrated IC for multi-function LDC monitor/TV with
resolutions up to SXGA/WXGA. It is configured with an integrated triple-ADC/PLL, an integrated
DVI/HDCP/HDMI receiver, a multi-standard TV video and audio decoder, a video de-interlacer, a
scaling engine, the MStarACE-3 color engine, an on-screen display controller, an 8-bit MCU, and a
built-in output panel interface. With external frame buffer, 3-D video decoding and processing are
fulfilled for high-quality TV application. To further reduce system costs, the MST9U88L also
integrates intelligent power management control capability for green-mode requirements and
spread-spectrum support for EMI management.




8
Pins description:
4, 5, 7, 8, 10, 11, 1, 2: HDMI input
16, 17: horizontal/vertical synchronous input
27, 25, 22: RGB input
30, 32, 35: YpbPr2 input
41, 44, 46: YpbPr1 input
48, 49: S-VIDEO input
54: AV1-V input
55: AV2-V input
57: TV-CVBS input
59: CVBS output(AVOUT-V)
71, 72: VGA-L/R input
73, 74: AV1(S)/AV2/ YpbPr1/ YpbPr2-L/R input
178: search program synchronous test input
188: HDMI hot-plug test output
189: image switch output
192: backlight control output
193: panel voltage contort output
85, 86: L/R output
234,236,238,239: I2S bus(AVOUT-A)
199-208: 4 pairs differential signal and 1pair clock signal output
174: SDA
175: SCL



2. R2S10401
R2S10401SP is a semiconductor integrated circuit consisting of PLL split-carrier VIF/SIF signal
processing system compliant with PAL.




9
10
Pin description:
1, 2: VIF input 10: TV-SIF output
23: SIF input 17: SDA
7: TV-CVBS output 18: SCL



3. MP7722DF
The MP7722 is a stereo 20W Class D Audio Amplifier. It is one of MPS'second generation of fully
integrated audio amplifiers which dramatically reduces solution size by integrating the following:
180m power MOSFETs
Startup / Shutdown pop elimination
Short circuit protection
Mute / Standby
The MP7722 utilizes a single ended output structure capable of delivering 2 x 20W into 4speakers.
MPS Class D Audio Amplifiers exhibit the high fidelity of a Class A/B amplifier at efficiencies greater
than 90%. The circuit is based on the MPS' proprietary variable frequency topology that delivers low
distortion, fast response time and operates on a single power supply.




11
12
Pin description:
1, 7: L/R input
19, 14: L/R output
6, 10: mute control input




13
Wiring diagram




down

up




down



up

IF adjustment




down

up




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 Possibly due to interference from automobile, train, high
bright spots 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.
There appear streaks or light color Check if interfered by other equipment and if interfered
on the screen possibly by the equipment like transmitting antenna,
non-professional radio station and cellular phone.


1.2 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 Check if all the picture setups have been corrected.
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 TV set and make proper adjustment according to the


15
signal types.
Picture too bright and there is Check if the contrast setting is too high.
distortion in the brightest area Possibly the output quality of DVD broadcaster is set too
high.
It maybe also due to improper terminal connection of the
video frequency signal in a certain position of the system.
Picture is whitish or too bright in the Check if the setting for the brightness is too high
darkest area of the picture Possibly the brightness grade of DVD player (broadcaster)
is set too high.
No picture or signal produced from Check if the cable is disconnected.
the displayer if "XXX in search" Check if it's connected to the proper terminal or if the input
appears. mode is correct.
There appears an indication - Check if the TV set can receive input signal. The signal is
"outside the receivable scope) not correctly identified and VGA format is beyond the
specified scope.
Remote control cannot work Check if the batteries are installed in the reverse order.
properly Check if the battery is effective.
Check the distance or angle from the monitor.
Check if there is any obstruct between the remote control
and the TV set.
Check if the remote control signal- receiving window is
exposed to strong fluorescence.
No picture and sound, but only Check if the antenna cable is correctly connected, or if it
hash. 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 When being played or in pause VHS picture search tape
tape, there are lines at the top or sometimes can't provide stable picture, which may lead to
bottom of the picture. 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

Quantity allowed Distance between two spots
Category Criteria
15" 20" 22" 30" 40" 15" 20" 22" 30" 40"
One single
5 2 5 2 3
spot
Bright Two
15mm
spot neighboring 2 1 2 1 1
spots
Total No. 5 2 5 2 3
15mm
One single
6 7 5 4 10
spot
Dark Two
10mm 5mm
spots neighboring 2 2 2 1 5
spots
Total No. 6 7 5 4 10
Total defected point 8 7 5 4 /



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).




17
3. Troubleshooting guide
3.1. No raster

Turn-on power supply, check yes
if the red indicator is light in
the STANDBY?

no


Check if X303 PIN3(5V) of Press POWER button on the red
main board is normal? unit or remote sensor control
and check the indicator.

blue
no
Check if the PIN3 of X301 on
Check STANDBY circuit of
main board is high-level?
power supply board
yes

Check back light board

no

no
Replace NS4 Check if the PIN11 of X303 in
main board is high-level?

yes


Replace N102 Check power
supply board




18
3.2. Raster, but no picture



Check if the unit button Does display OSD yes
yes
and remote control menu in screen when
operation? press menu button?

no
no Check if the all channels
yes
have no signal?

no

HDMI/VGA/YPRPB
Enter factory-menu, Which is no signal
initialization EEPROM, of channels
Replace then turn off the TV,
main board no turn on again, display
TV Replace
picture?
main board
yes

Adjust main board
again
Check if 1VPP signal
yes and noise wave of
XB201 11# on the TV
board?


no


Check if output IF
Replace TUNER1 no signal of TUNER1
(pin 11) is normal?


yes

Check IF(NZ100)
and its periphery




19
3.3.no sound (TV input)

Check if PIN2, 8, 13 and Check PIN3 and
yes yes
18 voltage of NA6 is PIN7 output wave of Replace NA6
normal? NA6

no
no

Check power board
Check PIN10 wave of
yes Replace NS4
NZ100



no

yes Replace NZ100
Check PIN11 wave of
TUNER1

no

Replace TUNER1




20
APPENDIX-A: Main assembly 9232HU2619

NAME NO. MAIN COMPONENT AND IT'S NO.

NZ100 R2S10401 (5271040101)
Analog board 6HU0195310
NA6 MP7722DF (5277722001)


Main board 6HU0490110 NS4 MST9U88L (5270988001)
Interface board 6HU0214610
Key board 6HU0130510
IR receiver board 6HU0220910
Power board 6HU0212010
Remote control 6010Y04601 RC-Y46-0A
Panel 5203325506 V320B1-L04
APPENDIX: Exploded view (LC-32X26)
PART LIST OF EXPLODED VIEW (LC-32X26)
NO. DESCRIPTION
1 5QG26W0090 Front cover
2 6153042500 Trans-connecting bracket assy
3 Screen
4 reception board assy
5 58A0028800 Connecting bracket of screen(left right)
6 Power board assy
7 58B0A24110/58B0024110 Main switch bracket
8 5830E96910 AV baffle (right)
9 Trans-connecting board assy
10 58A0041700 crystal FRAME (bottom)
11 5830097010 AV baffle (bottom)
12 5284000031 Socket
13 58A0040900 Stand bracket
14 5810046800 Connecting piece of speaker box(2)
15 6170558000 Speaker box assy
16 button board assy
17 58B0023910 SIDE Button board bracket
18 5840947010 Buttonbaffle
19 5HG26WH01C Rear cabinet
20 5830096610 Rear cabinetCover(1)
21 6151064900 Stand assy
22 5830096710 Rear cabinetCover(2)
23 58A0041100 trans-connector
24 58A0A40800 crystal frame (right)
25 574018901B Power board frame
26 58A0040700 crystal frame ( middle )
27 58A0041000 Mounting holder
28 58A0041600 crystal frame (upper )
29 58A0A40600 crystal frame (left)
30 Y740188010 Main board frame
31 5830F9681B AV baffle (left)
32 CPU board assy
33 Analog board assy
34 5293000042 Power switch
9232HU2619
Ver.1.0