LG 42LH20R User manual

LCD TV
SERVICE MANUAL
CAUTION
BEFORE SERVICING THE CHASSIS,
READ THE SAFETY PRECAUTIONS IN THIS MANUAL.
CHASSIS : LP91A
MODEL : 42LH20R 42LH20R-MA
North/Latin America http://aic.lgservice.com
Europe/Africa http://eic.lgservice.com
Asia/Oceania http://biz.lgservice.com
Internal Use Only

LGE Internal Use OnlyCopyright © 2009 LG Electronics. Inc. All right reserved.
Only for training and service purposes
- 2 -
CONTENTS
CONTENTS .............................................................................................. 2
PRODUCT SAFETY ..................................................................................3
SPECIFICATION ........................................................................................6
ADJUSTMENT INSTRUCTION .................................................................9
TROUBLE SHOOTING ............................................................................14
BLOCK DIAGRAM...................................................................................17
EXPLODED VIEW .................................................................................. 18
SVC. SHEET ...............................................................................................

LGE Internal Use OnlyCopyright © 2009 LG Electronics. Inc. All right reserved.
Only for training and service purposes
- 3 -
SAFETY PRECAUTIONS
Many electrical and mechanical parts in this chassis have special safety-related characteristics. These parts are identified by in the
Schematic Diagram and Exploded View.
It is essential that these special safety parts should be replaced with the same components as recommended in this manual to prevent
Shock, Fire, or other Hazards.
Do not modify the original design without permission of manufacturer.
General Guidance
An isolation Transformer should always be used during the
servicing of a receiver whose chassis is not isolated from the AC
power line. Use a transformer of adequate power rating as this
protects the technician from accidents resulting in personal injury
from electrical shocks.
It will also protect the receiver and it's components from being
damaged by accidental shorts of the circuitry that may be
inadvertently introduced during the service operation.
If any fuse (or Fusible Resistor) in this TV receiver is blown,
replace it with the specified.
When replacing a high wattage resistor (Oxide Metal Film Resistor,
over 1W), keep the resistor 10mm away from PCB.
Keep wires away from high voltage or high temperature parts.
Before returning the receiver to the customer,
always perform an AC leakage current check on the exposed
metallic parts of the cabinet, such as antennas, terminals, etc., to
be sure the set is safe to operate without damage of electrical
shock.
Leakage Current Cold Check(Antenna Cold Check)
With the instrument AC plug removed from AC source, connect an
electrical jumper across the two AC plug prongs. Place the AC
switch in the on position, connect one lead of ohm-meter to the AC
plug prongs tied together and touch other ohm-meter lead in turn to
each exposed metallic parts such as antenna terminals, phone
jacks, etc.
If the exposed metallic part has a return path to the chassis, the
measured resistance should be between 1MΩ and 5.2MΩ.
When the exposed metal has no return path to the chassis the
reading must be infinite.
An other abnormality exists that must be corrected before the
receiver is returned to the customer.
Leakage Current Hot Check (See below Figure)
Plug the AC cord directly into the AC outlet.
Do not use a line Isolation Transformer during this check.
Connect 1.5K/10watt resistor in parallel with a 0.15uF capacitor
between a known good earth ground (Water Pipe, Conduit, etc.)
and the exposed metallic parts.
Measure the AC voltage across the resistor using AC voltmeter
with 1000 ohms/volt or more sensitivity.
Reverse plug the AC cord into the AC outlet and repeat AC voltage
measurements for each exposed metallic part. Any voltage
measured must not exceed 0.75 volt RMS which is corresponds to
0.5mA.
In case any measurement is out of the limits specified, there is
possibility of shock hazard and the set must be checked and
repaired before it is returned to the customer.
Leakage Current Hot Check circuit
1.5 Kohm/10W
To Instrument's
exposed
METALLIC PARTS
Good Earth Ground
such as WATER PIPE,
CONDUIT etc.
AC Volt-meter
When 25A is impressed between Earth and 2nd Ground
for 1 second, Resistance must be less than 0.1
*Base on Adjustment standard
IMPORTANT SAFETY NOTICE
0.15uF
Ω

LGE Internal Use OnlyCopyright © 2009 LG Electronics. Inc. All right reserved.
Only for training and service purposes
- 4 -
CAUTION: Before servicing receivers covered by this service
manual and its supplements and addenda, read and follow the
SAFETY PRECAUTIONS on page 3 of this publication.
NOTE: If unforeseen circumstances create conflict between the
following servicing precautions and any of the safety precautions on
page 3 of this publication, always follow the safety precautions.
Remember: Safety First.
General Servicing Precautions
1. Always unplug the receiver AC power cord from the AC power
source before;
a. Removing or reinstalling any component, circuit board
module or any other receiver assembly.
b. Disconnecting or reconnecting any receiver electrical plug or
other electrical connection.
c. Connecting a test substitute in parallel with an electrolytic
capacitor in the receiver.
CAUTION: A wrong part substitution or incorrect polarity
installation of electrolytic capacitors may result in an
explosion hazard.
2. Test high voltage only by measuring it with an appropriate high
voltage meter or other voltage measuring device (DVM,
FETVOM, etc) equipped with a suitable high voltage probe.
Do not test high voltage by "drawing an arc".
3. Do not spray chemicals on or near this receiver or any of its
assemblies.
4. Unless specified otherwise in this service manual, clean
electrical contacts only by applying the following mixture to the
contacts with a pipe cleaner, cotton-tipped stick or comparable
non-abrasive applicator; 10% (by volume) Acetone and 90% (by
volume) isopropyl alcohol (90%-99% strength)
CAUTION: This is a flammable mixture.
Unless specified otherwise in this service manual, lubrication of
contacts in not required.
5. Do not defeat any plug/socket B+ voltage interlocks with which
receivers covered by this service manual might be equipped.
6. Do not apply AC power to this instrument and/or any of its
electrical assemblies unless all solid-state device heat sinks are
correctly installed.
7. Always connect the test receiver ground lead to the receiver
chassis ground before connecting the test receiver positive
lead.
Always remove the test receiver ground lead last.
8. Use with this receiver only the test fixtures specified in this
service manual.
CAUTION: Do not connect the test fixture ground strap to any
heat sink in this receiver.
Electrostatically Sensitive (ES) Devices
Some semiconductor (solid-state) devices can be damaged easily
by static electricity. Such components commonly are called
Electrostatically Sensitive (ES) Devices. Examples of typical ES
devices are integrated circuits and some field-effect transistors and
semiconductor "chip" components. The following techniques
should be used to help reduce the incidence of component
damage caused by static by static electricity.
1. Immediately before handling any semiconductor component or
semiconductor-equipped assembly, drain off any electrostatic
charge on your body by touching a known earth ground.
Alternatively, obtain and wear a commercially available
discharging wrist strap device, which should be removed to
prevent potential shock reasons prior to applying power to the
unit under test.
2. After removing an electrical assembly equipped with ES
devices, place the assembly on a conductive surface such as
aluminum foil, to prevent electrostatic charge buildup or
exposure of the assembly.
3. Use only a grounded-tip soldering iron to solder or unsolder ES
devices.
4. Use only an anti-static type solder removal device. Some solder
removal devices not classified as "anti-static" can generate
electrical charges sufficient to damage ES devices.
5. Do not use freon-propelled chemicals. These can generate
electrical charges sufficient to damage ES devices.
6. Do not remove a replacement ES device from its protective
package until immediately before you are ready to install it.
(Most replacement ES devices are packaged with leads
electrically shorted together by conductive foam, aluminum foil
or comparable conductive material).
7. Immediately before removing the protective material from the
leads of a replacement ES device, touch the protective material
to the chassis or circuit assembly into which the device will be
installed.
CAUTION: Be sure no power is applied to the chassis or circuit,
and observe all other safety precautions.
8. Minimize bodily motions when handling unpackaged
replacement ES devices. (Otherwise harmless motion such as
the brushing together of your clothes fabric or the lifting of your
foot from a carpeted floor can generate static electricity
sufficient to damage an ES device.)
General Soldering Guidelines
1. Use a grounded-tip, low-wattage soldering iron and appropriate
tip size and shape that will maintain tip temperature within the
range or 500°F to 600°F.
2. Use an appropriate gauge of RMA resin-core solder composed
of 60 parts tin/40 parts lead.
3. Keep the soldering iron tip clean and well tinned.
4. Thoroughly clean the surfaces to be soldered. Use a mall wire-
bristle (0.5 inch, or 1.25cm) brush with a metal handle.
Do not use freon-propelled spray-on cleaners.
5. Use the following unsoldering technique
a. Allow the soldering iron tip to reach normal temperature.
(500°F to 600°F)
b. Heat the component lead until the solder melts.
c. Quickly draw the melted solder with an anti-static, suction-
type solder removal device or with solder braid.
CAUTION: Work quickly to avoid overheating the circuit
board printed foil.
6. Use the following soldering technique.
a. Allow the soldering iron tip to reach a normal temperature
(500°F to 600°F)
b. First, hold the soldering iron tip and solder the strand against
the component lead until the solder melts.
c. Quickly move the soldering iron tip to the junction of the
component lead and the printed circuit foil, and hold it there
only until the solder flows onto and around both the
component lead and the foil.
CAUTION: Work quickly to avoid overheating the circuit
board printed foil.
d. Closely inspect the solder area and remove any excess or
splashed solder with a small wire-bristle brush.
SERVICING PRECAUTIONS

LGE Internal Use OnlyCopyright © 2009 LG Electronics. Inc. All right reserved.
Only for training and service purposes
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IC Remove/Replacement
Some chassis circuit boards have slotted holes (oblong) through
which the IC leads are inserted and then bent flat against the
circuit foil. When holes are the slotted type, the following technique
should be used to remove and replace the IC. When working with
boards using the familiar round hole, use the standard technique
as outlined in paragraphs 5 and 6 above.
Removal
1. Desolder and straighten each IC lead in one operation by gently
prying up on the lead with the soldering iron tip as the solder
melts.
2. Draw away the melted solder with an anti-static suction-type
solder removal device (or with solder braid) before removing the
IC.
Replacement
1. Carefully insert the replacement IC in the circuit board.
2. Carefully bend each IC lead against the circuit foil pad and
solder it.
3. Clean the soldered areas with a small wire-bristle brush.
(It is not necessary to reapply acrylic coating to the areas).
"Small-Signal" Discrete Transistor
Removal/Replacement
1. Remove the defective transistor by clipping its leads as close as
possible to the component body.
2. Bend into a "U" shape the end of each of three leads remaining
on the circuit board.
3. Bend into a "U" shape the replacement transistor leads.
4. Connect the replacement transistor leads to the corresponding
leads extending from the circuit board and crimp the "U" with
long nose pliers to insure metal to metal contact then solder
each connection.
Power Output, Transistor Device
Removal/Replacement
1. Heat and remove all solder from around the transistor leads.
2. Remove the heat sink mounting screw (if so equipped).
3. Carefully remove the transistor from the heat sink of the circuit
board.
4. Insert new transistor in the circuit board.
5. Solder each transistor lead, and clip off excess lead.
6. Replace heat sink.
Diode Removal/Replacement
1. Remove defective diode by clipping its leads as close as
possible to diode body.
2. Bend the two remaining leads perpendicular y to the circuit
board.
3. Observing diode polarity, wrap each lead of the new diode
around the corresponding lead on the circuit board.
4. Securely crimp each connection and solder it.
5. Inspect (on the circuit board copper side) the solder joints of
the two "original" leads. If they are not shiny, reheat them and if
necessary, apply additional solder.
Fuse and Conventional Resistor
Removal/Replacement
1. Clip each fuse or resistor lead at top of the circuit board hollow
stake.
2. Securely crimp the leads of replacement component around
notch at stake top.
3. Solder the connections.
CAUTION: Maintain original spacing between the replaced
component and adjacent components and the circuit board to
prevent excessive component temperatures.
Circuit Board Foil Repair
Excessive heat applied to the copper foil of any printed circuit
board will weaken the adhesive that bonds the foil to the circuit
board causing the foil to separate from or "lift-off" the board. The
following guidelines and procedures should be followed whenever
this condition is encountered.
At IC Connections
To repair a defective copper pattern at IC connections use the
following procedure to install a jumper wire on the copper pattern
side of the circuit board. (Use this technique only on IC
connections).
1. Carefully remove the damaged copper pattern with a sharp
knife. (Remove only as much copper as absolutely necessary).
2. carefully scratch away the solder resist and acrylic coating (if
used) from the end of the remaining copper pattern.
3. Bend a small "U" in one end of a small gauge jumper wire and
carefully crimp it around the IC pin. Solder the IC connection.
4. Route the jumper wire along the path of the out-away copper
pattern and let it overlap the previously scraped end of the good
copper pattern. Solder the overlapped area and clip off any
excess jumper wire.
At Other Connections
Use the following technique to repair the defective copper pattern
at connections other than IC Pins. This technique involves the
installation of a jumper wire on the component side of the circuit
board.
1. Remove the defective copper pattern with a sharp knife.
Remove at least 1/4 inch of copper, to ensure that a hazardous
condition will not exist if the jumper wire opens.
2. Trace along the copper pattern from both sides of the pattern
break and locate the nearest component that is directly
connected to the affected copper pattern.
3. Connect insulated 20-gauge jumper wire from the lead of the
nearest component on one side of the pattern break to the lead
of the nearest component on the other side.
Carefully crimp and solder the connections.
CAUTION: Be sure the insulated jumper wire is dressed so the
it does not touch components or sharp edges.

LGE Internal Use OnlyCopyright © 2009 LG Electronics. Inc. All right reserved.
Only for training and service purposes
- 6 -
SPECIFICATION
NOTE : Specifications and others are subject to change without notice for improvement .
4. Electrical specification
4.1. General Specification
1. Application range
This spec sheet is applied to LCD TV used LP91A chassis.
2. Specification
Each part is tested as below without special appointment.
1) Temperature : 25±5ºC (77±9ºF), CST : 40±5ºC
2) Relative Humidity : 65±10%
3) Power Voltage : Standard input voltage(100~240V@50/60Hz)
* Standard Voltage of each products is marked by models.
4) Specification and performance of each parts are followed
each drawing and specification by part number in
accordance with BOM.
5) The receiver must be operated for about 5 minutes prior to
the adjustment.
3. Test method
1) Performance: LGE TV test method followed
2) Demanded other specification
- Safety: CE, IEC specification
- EMC : CE, IEC
No Item Specification Measurement Remark
1 Screen Size 42” wide Color Display Module Resolution : 1366*768
2 Aspect Ratio 16:9
3 LCD Module 42” TFT WXGA LCD
4 Operating Environment Temp.: 0 ~ 40 deg
Humidity : 0 ~ 85 %
5 Storage Environment Temp.: -20 ~ 60 deg
Humidity : 0~ 85 %
6 Input Voltage AC100-240V~, 50/60Hz
≤ 200 W 42” HD
7 LDC Module HD 983 x 576 x 46 Unit : mm
(Maker : LGD) 0.227 x 0.681
18 EEFL
Coating 3H

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Only for training and service purposes
No. Item Min. Typ. Max. Unit Maker Remark
1. Luminance 400 500 cd/m2
(W/O PC mode)
2. VIew angle (R/L, U/D) 178 / 178 degree LGD
3. Color Coordinates White Wx Typ 0.279 Typ LGD 42”(HD)
Wy -0.03 0.292 +0.03 LC420WXE-SBA1
RED Xr 0.637
Yr 0.335
Green Xg 0.290
Yg 0.611
Blue Xb 0.145
Yb 0.062
4. Contrast ratio 800:1 1200:1
5. Luminance Variation 1.3
5. Chroma& Brightness (Optical)
5.1. LCD Module
the Color Coordinates check condition
- 50cm from the surface, Full White Pattern
- Picture mode Vivid
6. Component Video Input (Y, PB, PR)
No Specification Remark
Resolution H-freq(kHz) V-freq(Hz) Pixel Clock(MHz)
1 720* 480 15.73 59.94 13.500 SDTV, DVD 480I( 525I)
2 720* 480 15.75 60.00 13.514 SDTV, DVD 480I( 525I)
3 720* 576 15.625 50.00 13.500 SDTV, DVD 576I( 625I) 50Hz
4 720* 480 31.47 59.94 27.000 SDTV 480P
5 720* 480 31.50 60.00 27.027 SDTV 480P
6 720* 576 31.25 50.00 27.000 SDTV 576P 50Hz
7 1280* 720 44.96 59.94 74.176 HDTV 720P
8 1280* 720 45.00 60.00 74.250 HDTV 720P
9 1280* 720 37.50 50.00 74.25 HDTV 720P 50Hz
10 1920* 1080 28.125 50.00 74.250 HDTV 1080I 50Hz,
11 1920* 1080 33.72 59.94 74.176 HDTV 1080I
12 1920* 1080 33.75 60.00 74.25 HDTV 1080I
13 1920* 1080 56.25 50 148.5 HDTV 1080P
14 1920* 1080 67.432 59.94 148.350 HDTV 1080P
15 1920* 1080 67.5 60.00 148.5 HDTV 1080P

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Only for training and service purposes
No Specification Proposed Remark
Resolution H-freq(kHz) V-freq(Hz) Pixel Clock(MHz)
1 640* 350 31.468 70.09 25.17 EGA
2 720* 400 31.469 70.09 28.32 DOS
3 640* 480 31.469 59.94 25.17 VESA( VGA)
4 800* 600 37.879 60.317 40 VESA( SVGA)
5 1024* 768 48.363 60.004 65 VESA( XGA)
6 1280* 768 47.776 59.87 79.5 VESA( WXGA)
7 1360* 768 47.72 59.799 84.75 VESA( WXGA)
8 1280* 1024 63.668 59.895 109.00 XGA Only FHD Model
9 1920* 1080 66.587 59.934 138.50 WUXGA(Reduced Blanking) Only FHD Model
7. RGB
7.1. Analog PC, RGB- DTV –NOT SUPPORT
8. HDMI Input
8.1. PC –Spec. out but it can be shown the picture at only HDMI/ DVI IN 1 via DVI to HDMI Cable)
No Resolution H-freq(kHz) V-freq.(Hz) Pixel clock(MHz) Proposed Remark
1 640 x 480 31.469 59.94 25.17 VESA( VGA)
2 800 x 600 37.879 60.317 40.00 VESA( SVGA)
3 1024 x 768 48.363 60.004 65.00 VESA( XGA)
4 1280 x 768 47.776 59.87 79.5 VESA( WXGA)
5 1360 x 768 47.72 59.799 84.62 VESA( WXGA)
6 1366 x 768 47.7 60.00 84.62 WXGA
7 1280 x 1024 63.595 60.00 108.875 SXGA
8 1920 x 1080 66.647 59.988 138.625 WUXGA
8.2. DTV Mode
No Specification Remark
Resolution H-freq(kHz) V-freq(Hz) Pixel Clock(MHz)
1 720 x 480 15.73 59.94 13.500 SDTV, DVD 480I(525I) Spec. out
2 720 x 480 15.75 60.00 13.514 SDTV, DVD 480I(525I) but display.
3 720 x 576 15.625 50.00 13.500 SDTV, DVD 576I(625I) 50Hz
4 720 x 480 31.47 59.94 27 SDTV 480P
5 720 x 480 31.5 60.00 27.027 SDTV 480P
6 720 x 576 31.25 50.00 27 SDTV 576P
7 1280 x 720 44.96 59.94 74.176 HDTV 720P
8 1280 x 720 45 60.00 74.25 HDTV 720P
9 1280 x 720 37.5 50.00 74.25 HDTV 720P
10 1920 x 1080 28.125 50.00 74.25 HDTV 1080I
11 1920 x 1080 33.72 59.94 74.176 HDTV 1080I
12 1920 x 1080 33.75 60.00 74.25 HDTV 1080I
13 1920 x 1080 56.25 50.00 148.5 HDTV 1080P
14 1920 x 1080 67.432 59.94 148.350 HDTV 1080P
15 1920 x 1080 67.5 60.00 148.5 HDTV 1080P
16 1920 x 1080 27 24.00 74.25 HDTV 1080P
17 1920 x 1080 33.75 30.00 74.25 HDTV 1080P

LGE Internal Use OnlyCopyright © 2009 LG Electronics. Inc. All right reserved.
Only for training and service purposes
- 9 -
ADJUSTMENT INSTRUCTION
1. Application Range
This specification sheet is applied to all of the LCD TV,
LP91A/B/C/D chassis.
2. Specification
1) Because this is not a hot chassis, it is not necessary to use
an isolation transformer. However, the use of isolation
transformer will help protect test instrument.
2) Adjustment must be done in the correct order.
3) The adjustment must be performed in the circumstance of
25 ±5 °C of temperature and 65±10% of relative humidity if
there is no specific designation.
4) The input voltage of the receiver must keep 100~220V,
50/60Hz.
5) Before adjustment, execute Heat-Run for 5 minutes at RF
no signal.
3. Adjustment items
3.1. PCB assembly adjustment items
(1) Download the MSTAR main software
(IC800, Mstar ISP Utility)
1) Using D/L Jig
2) Using USB Memory Stick.
(2) Input Tool-Option/Area option.
(3) Download the EDID
- EDID datas are automatically download when adjusting
the Tool Option2
(4) ADC Calibration – RGB / Component
(4) Check SW Version.
3.2. SET assembly adjustment items
(1) Input Area option
(2) Adjustment of White Balance : Auto & Manual
(3) Input Tool-Option/Area option
(4) Intelligent Sensor Inspection Guide
(5) Preset CH information
(6) Factoring Option Data input
4. PCB assembly adjustment method
4.1. Mstar Main S/W program download
4.1.1. Using D/L Jig
(1) Preliminary steps
1) Connect the download jig to D-sub(RGB) jack
(2) Download steps
1) Execute ‘ISP Tool’ program, the main window(Mstar ISP
utility Vx.x.x) will be opened
2) Click the “Connect” button and confirm “Dialog Box”
3) Click the “Config.” button and Change speed I2C Speed
setting : 350Khz~400Khz
4) Read and write bin file.
Click “(1)Read” tab, and then load download
file(XXXX.bin) by clicking “Read”.
- LH20/ LH30
1
Filexxx.bin
1
Filexxx.binFilexxx.bin

5) Click “(2)Auto” tab and set as below
6) Click “(3)Run”.
7) After downloading, you can see the “(4)Pass” message.
4.1.2. Using the Memory Stick
* USB download : Service Mode
1) Insert the USB memory stick to the ISB port.
2) Automatically detect the SW Version.
-> S/W download process is executed automatically.
3) Show the message “Copy the file from the Memory”
4) After Finished the Download, Automatically DC Off -> On
5) Check The update SW Version.
4.2. Input tool option.
Adjust tool option refer to the BOM.
- Tool Option Input : PCBA Check Process
- Area Option Input : Set Assembly Process
After Input Tool Option and AC off
Before PCBA check, you have to change the Tool option and
have to AC off/on (Plug out and in)
(If missing this process, set can operate abnormally)
(1) Profile : Must be changed the option value because being
different with some setting value depend on
module maker, inch and market
(2) Equipment : adjustment remote control.
(3). Adjustment method
- The input methods are same as other chassis.(Use IN-
START Key on the Adjust Remocon.)
(If not changed the option, the input menu can differ the
model spec.)
Refer to Job Expression of each main chassis ass’y
(EBTxxxxxxxx) for Option value
Caution : Don’t Press “IN-STOP” key after completing the
function inspection.
4.3. EDID D/L method
Recommend that don’t connect HDMI and RGB(D-SUB) cable
when downloading the EDID.
If not possible, recommend that connect the MSPG equipment.
There are two methods of downloading the edid data
4.3.1. 1st Method
EDID datas are automatically downloaded when adjusting the
Tool Option2.
Automatically downloaded when pushing the enter key after
adjusting the tool option2.
It takes about 2seconds.
4.3.2. 2nd Method
* Caution :
Must be checked that the tool option is right or not.
If tool option is wrong, hdmi edid data could not be
downloaded well.
1) Press the ADJ key
2) Move to the EDID D/L and Press the right direction key(G)
3) Press the right direction key(G) at Start.
4) After about a few seconds, appear “OK”, then compele.
4.3.3. RS-232C command Method
(1) Command : AE 00 10
* Caution
Don’t connect HDMI and RGB(D-SUB) cable when
downloading the EDID.
If the cables are connected, Downloading of edid could be
failed.
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Only for training and service purposes
1
Filexxx.bin

4.3.4. EDID data
(1) Analog(RGB): 128bytes>
(2) HDMI 1 : 256Bytes
(3) HDMI 2 : 256Bytes
4.4. ADC Calibration
4.4.1. ADC Calibration - Component (Using External pattern)
(1) Required Equipments
- Remote controller for adjustment
- MSPG-925F/MSPG-1025/MSPG-3233 Pattern Generator
(2) Process
1) Change the Input to Component1 or 2 mode.
2) Input the Component 480i@60Hz 100% Color Bar
YPbPr signal into Component1 or 2.
(MSPG-925F Model: 209 / Pattern: 65 )
3) Press ADJ key on R/C for adjustment.
4) Enter Password number. Password is “0 0 0 0”.
5) Select “0. ADC calibration : Component” by using D/E
(CH +/-) and press ENTER(A).
6) ADC adjustment is executed automatically .
7) When ADC adjustment is finished, this OSD appear
4.4.2. ADC Calibration - RGB (Using External pattern)
(1) Required Equipments
- Remote controller for adjustment
- MSPG-925F/MSPG-1025/MSPG-3233 Pattern Generator
(2) Process
1) Change the Input to RGB mode..
2) Input the PC 1024x768@60Hz Horizontal Color Bar
signal into RGB.
(MSPG-925F Model: 60 / Pattern: 65 )
3) Press ADJ key on R/C for adjustment.
4) Enter Password number. Password is “0 0 0 0”.
5) Select “0. ADC calibration : RGB” by using D/E(CH +/-)
and press ENTER(A).
6) ADC adjustment is executed automatically .
7) When ADC adjustment is finished, this OSD appear
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Only for training and service purposes
OK
OK

4.5. Check SW Version
(1) Method
1) Push In-star key on Adjust remote-controller.
2) SW Version check
Check “SW VER : V3.xx” – LH70
5. PCB assembly adjustment method
5.1. Input Area-Option
(1) Profile : Must be changed the Area option value because
being different of each Country’s Language and
signal Condition.
(2) Equipment : adjustment remote control.
(3) Adjustment method
- The input methods are same as other chassis.(Use IN-
START Key on the Adjust Remocon.)
Refer to Job Expression of each main chassis ass’y
(EBTxxxxxxxx) for Option value.
* White Balance Adjustment
- Purpose : Adjust the color temperature to reduce the
deviation of the module color temperature.
- Principle : To adjust the white balance without the saturation,
Fix the one of R/G/B gain to 192 (default data)
and decrease the others.
- Adjustment mode : Three modes – Cool / Medium / Warm
- Required Equipment
1) Remote controller for adjustment
2) Color Analyzer : CA100+ or CA-210 or same product -
LCD TV( ch : 9 ),
(should be used in the calibrated ch by CS-1000)
3) Auto W/B adjustment instrument(only for Auto adjustment)
5.2. Adjustment of White Balance
: (For automatic adjustment)
* LP91A~D Support RS-232C & I2C DDC Communication-
White Balance Mode.
(1) Enter the adjustment mode of DDC
- Set command delay time : 50ms
- Enter the DDC adjustment mode at the same time heat-
run mode when pushing the power on by power only key
- Maintain the DDC adjustment mode with same condition
of Heat-run => Maintain after AC off/on in status of Heat-
run pattern display)
(2) Release the DDC adjustment mode
- Release the adjust mode after AC off/on or std-by off/on
in status of finishing the Hear-run mode
- Release the Adjust mode when receiving the aging off
command(F3 00 00) from adjustment equipment.
- Need to transmit the aging off command to TV set after
finishing the adjustment.
- Check DDC adjust mode release by exit key and release
DDC adjust mode)
(3) Enter the adjust mode of white balance)
- Enter the white balance adjustment mode with aging
command (F3, 00, FF)
* Luminance min value is 150cd in the Cool/Medium/Warm
mode(For LCD)
5
.3. Adjustment of White Balance
(for Manual adjustment)
(1) Color analyzer(CA100+, CA210) should be used in the
calibrated ch by CS-1000
(2) Operate the zero-calibration of the CA100+ or CA-210,
then stick sensor to the module when adjusting.
(3) For manual adjustment, it is also possible by the following
sequence.
1) Select white pattern of heat-run by pressing “POWER
ON” key on remote control for adjustment then operate
heat run longer than 15 minutes. (If not executed this
step, the condition for W/B may be different.)
2) Push “Exit” key.
3) Change to the AV mode by remote control.
4) Input external pattern (85% white pattern)
5) Push the ADJ key -> Enter “0000” (Password)
6) Select “3. W/B ADJUST”
7) Enter the W/B ADJUST Mode
8) Stick the sensor to the center of the screen and select
each items (Red/Green/Blue Gain and Offset) using
D/E(CH +/-) key on R/C..
9) Adjust R/ G/ B Gain using F/G(VOL +/-) key on R/C.
10) Adjust three modes all (Cool / Medium / Warm) : Fix
the one of R/G/B gain and change the others
11) When adjustment is completed, Enter “COPY ALL”.
12) Exit adjustment mode using EXIT key on R/C.
- 12 - LGE Internal Use OnlyCopyright © 2009 LG Electronics. Inc. All right reserved.
Only for training and service purposes

* CASE
First adjust the coordinate far away from the target value(x, y).
1. x, y > target
i) Decrease the R, G.
2. x, y < target
i) First decrease the B gain,
ii) Decrease the one of the others.
3. x > target, y < target
i) First decrease B, so make y a little more than the target.
ii) Adjust x value by decreasing the R
4. x < target, y > target
i) First decrease B, so make x a little more than the target.
ii) Adjust x value by decreasing the G
(4) Standard color coordinate and temperature when using the
CA100+ or CA210 equipment
To check the Coordinates of White Balance, you have to
measure at the below conditions.
Picture Mode : User 1
Dynamic Contrast : Off
Dynamic Colour : Off
(If you miss the upper condition, the coordinates of W/B
can be lower than the spec.)
- 13 - LGE Internal Use OnlyCopyright © 2009 LG Electronics. Inc. All right reserved.
Only for training and service purposes
Coordinate
Mode x y Temp uv∆
Cool 0.276±0.002 0.283±0.002 11,000K 0.000
Medium 0.285±0.002 0.293±0.002 9,300K 0.000
Warm 0.313±0.002 0.329±0.002 6,500K 0.003

LGE Internal Use OnlyCopyright © 2009 LG Electronics. Inc. All right reserved.
Only for training and service purposes
- 14 -
TROUBLESHOOTING
No power
(LED indicator off)
Check 24V, 12V, 5,2V
of Power B/D
Check short of Main B/D
or Change Power B/D
Pass
Check Output of
IC1001, IC1003, IC1007
Check P307 Connector
Change LEDAssy
: [A] PROCESS
Fail
Fail
Pass
Pass
Check LEDAssy
Change IC1002,, Q1003
Pass
Check short of IC1001,
IC1003, IC1007
Fail
Re-soldering or Change defect
part of IC1001, IC1003, IC1007
Fail
No Raster [B]: Process
Check LED status
On Display Unit Repeat A PROCESS
Pass
Fail
Check Output of IC802 Change IC802
Fail
Change Inverter Connector
Or Inverter
Fail
Pass
Fail
Pass
Change Module
Fail
Check LVDS Cable
Pass
Check Panel Link Cable
Or Module
Change Panel Link Cable
Or Module
Check Inverter Connector
Or Inverter
Pass

LGE Internal Use OnlyCopyright © 2009 LG Electronics. Inc. All right reserved.
Only for training and service purposes
- 15 -
No Raster on PC Signal
Check Input source Cable
and Jack
Pass
Re-soldering or
Change the defect part
Pass
Check the Input/Output
Of IC100 Fail
Re-soldering or
Change the defect part,
Check RGB EDID Data
Repeat [A], & [B] Process
Pass
Check the Input/Output
Of J104 Fail
Pass
Check the Input/Output
Of IC800 Fail
Re-soldering or
Change the defect part
Pass
No Raster on COMMPONENT Signal
Check Input source
Cable And Jack
Pass
Re-soldering or
Change the defect part
Pass
Check the Input/Output
Of IC800 Fail
Re-soldering or
Change the defect part
Repeat [A], & [B] Process
Check The Input/Output
Of JK101 Fail
Pass
No Raster on HDMI Signal
Check Input source
Cable And Jack
Pass
Check the Input/Output
Of JK301, JK302, JK303 Fail
Re-soldering or
Change the defect part
Pass
Pass
Check the Input/Output
Of IC300, IC301, JK302 Fail
Re-soldering or
Change the defect part
Check HDMI EDID Data
Re-download HDCP
Pass
Pass
Check the Input/Output
Of IC800 Fail
Re-soldering or
Change the defect part
Repeat [A], & [B] Process

LGE Internal Use OnlyCopyright © 2009 LG Electronics. Inc. All right reserved.
Only for training and service purposes
- 16 -
No Sound
Check The Input Sourse.
Check The Input/Output
Of IC600.
Re-soldering or
Change the defect part.Fail
Pass
Pass
Check The Speaker. Change Speaker.
Fail
Check The Speaker Wire.
Pass
Change The Source Input.
Fail
No Raster On AV (Video, S-Video)Signal No Signal On TV(RF) Signal
Check Input source
Cable And Jack
Pass
Check Input source
Cable And Jack
Pass
Check The Input/Output
Of JK101, JK201
Pass
Re-soldering or
Change the defect part
Pass
Fail
Pass
Repeat [A], & [B] Process
Check the Input/Output
Of IC800 Fail
Re-soldering or
Change the defect part
Pass
Check The Input/Output
Of TU500
Pass
Re-soldering or
Change the defect part
Pass
Fail
Check the Input/Output
Of IC800 Fail
Re-soldering or
Change the defect part
Repeat [A], & [B] Process

LGE Internal Use OnlyCopyright © 2009 LG Electronics. Inc. All right reserved.
Only for training and service purposes
- 17 -
BLOCK DIAGRAM
RGB_PC PC_Audio TV (RF) COMP1
HDMI1 HDMI2
RS232
TX
232C Driver
ST3232C
Tx/ Rx : 15Vpp PC_R/G/B/HS/VS PC_Audio_L/ R :700mVrms MNT_OUT: 1Vpp
SIDE_V :1Vpp SIDE_L/ SIDE_R :500mVrms
DDR2(512MB)
L_SPK_OUT R_SPK_OUT
EEPROM
24C02
Comp1_L/ R :500mVrms
TUNER
AV1_VIN:1Vpp AV11_LIN/RIN :500mVrms
PWM
NTP3100L
MNT_OUT
MNT_LOUT/ ROUT: 500mVrms
AV2 (Side AV)
MAIN SCALER
TXD / RXD :5V Digital
COMP1_Y/ Pb/ Pr: 1/0.7Vpp COMP2_Y/ Pb/ Pr: 1/0.7Vpp IR HDMI_DATA_1 HDMI_DATA_2
HDMI1_SCL/ SDA
OUT_E_TX_CLK
OUT_E_TX_E OUT_E_TX_D OUT_E_TX_C OUT_E_TX_B OUT_E_TX_A
TU_MAIN
S I F
COMP1_Y/ Pb/ Pr 1/ 0.7Vpp
AV1_VIN
PC_Audio _L/ R COMP1_LIN/ RIN
L_CH
R_CH
LVDS connector
TU_MAIN SUB_SCLSDA
EEPROM
24C02
EEPROM
24C02
SIF
AV1_LIN/ RIN MNT_L/ R OUT
AV1 MNT_OUT
Comp2_L/ R :500mVrms COMP2_Y/ Pb/ :1/ 0.7Vpp
COMP2_LIN/ RIN
COMP2
OUT_O_TX_CLK
OUT_O_TX_E OUT_O_TX_D OUT_O_TX_C OUT_O_TX_B OUT_O_TX_A
PC_R/G/B/HS/VS
HDM 2_SCL/ SDA
PC_SCL/ SDA
MNT_VOUT
AV2_VIN AV2_LIN/ RIN
IIS_OUT
USB USB_DN/ PN
AUDIO
AMP
HDMI3_SCL/ SDA
EEPROM
24C02
HDMI_DATA_3
TMDS TMDS TMDS
HDMI3
USB For D/ L
EEPROM(256K) Serial Flash (8MByte)
RGB_PC PC_Audio TV (RF) COMP1
HDMI1 HDMI2
RS232
TX
232C Driver
ST3232C
±
PC_R/G/B/HS/VS PC_Audio_L/ R :700mVrms MNT_OUT: 1Vpp
SIDE_V :1Vpp SIDE_L/ SIDE_R :500mVrms
DDR2(512MB)
EEPROM
24C02
Comp1_L/ R :500mVrms
TUNER
AV1_VIN:1Vpp AV11_LIN/RIN :500mVrms
PWM
NTP3100L
MNT_OUT
MNT_LOUT/ ROUT: 500mVrms
AV2 (Side AV)
MAIN SCALER
TXD / RXD :5V Digital
COMP1_Y/ Pb/ Pr: 1/0.7Vpp COMP2_Y/ Pb/ Pr: 1/0.7Vpp HDMI_DATA_1 HDMI_DATA_2
_
OUT_E_TX_CLK±
OUT_E_TX_ ± OUT_E_TX_ ± OUT_E_TX_C± OUT_E_TX_B± OUT_E_TX_A±
TU_MAIN
S I F
COMP1_Y/ Pb/ P :1/ 0.7Vpp
AV1_VIN
PC_Audio _L/ R COMP1_LIN/ RIN
L_CH
R_CH
LVDS connector
TU_MAIN /
EEPROM
24C02
EEPROM
24C02
SIF
AV1_LIN/ RIN MNT_L/ R OUT
AV1 MNT_OUT
Comp2_L/ R :500mVrms COMP2_Y/ Pb/Pr 1/ 0.7Vpp
COMP2_LIN/ RIN
COMP2
OUT_O_TX_C ±
OUT_O_TX_E± OUT_O_TX_D± OUT_O_TX_C± OUT_O_TX_B± OUT_O_TX_A±
PC_R/G/B/HS/VS
PC_SCL/ SDA
PC_SCL/ SDA
MNT_VOUT
AV2_VIN AV2_LIN/ RIN
IIS_OUT
USB USB_DN/ PN
AUDIO
AMP
HDMI3_SCL/ SDAHDMI3_SCL/ SDA
EEPROM
24C02
HDMI_DATA_3
TMDS TMDS TMDS
HDMI3
USB For D/ L
EEPROM(256K) Serial Flash (8MByte)

- 18 - LGE Internal Use OnlyCopyright LG Electronics. Inc. All right reserved.
Only for training and service purposes
300
200
A5
801
LV1
A2
A10
802
803
804 805
521
400
900
120
510
500
310
540
530
550
806
EXPLODED VIEW
Many electrical and mechanical parts in this chassis have special safety-related characteristics. These
parts are identified by in the Schematic Diagram and EXPLODED VIEW.
It is essential that these special safety parts should be replaced with the same components as
recommended in this manual to prevent X-RADIATION, Shock, Fire, or other Hazards.
Do not modify the original design without permission of manufacturer.
IMPORTANT SAFETY NOTICE

THE SYMBOL MARK OF THIS SCHEMETIC DIAGRAM INCORPORATES SPECIAL FEATURES IMPORTANT FOR PROTECTION FROM X-RADIATION. FILRE AND ELECTRICAL SHOCK HAZARDS, WHEN SERVICING IF IS ESSENTIAL THAT ONLY MANUFATURES SPECFIED PARTS BE USED FOR THE CRITICAL COMPONENTS IN THE SYMBOL MARK OF THE SCHEMETIC.
CVBS_LIN
MUTE_LINE
AUDIO_R
SD05
ZD100
100uF16V C102
SD05
ZD103
SD05
ZD105
MNT_ROUT
CVBS_VIN
SPK_R+_HOTEL
RT1C3904-T112
Q100
E
BC
SPK_R-_HOTEL
CVBS_RIN
SD05
ZD104
10uF
16V
C101
MUTE_LINE
SD05
ZD101
SD05
ZD102
MNT_LOUT
RT1C3904-T112
Q101 E
B
C
MNT_VOUT
10uF
16V
C100
30V NON_HOTEL_OPT D102 30V NON_HOTEL_OPT D103
30V
D101
30V
ADUC30S03010L_AMODIODE
D100
30V D104 30V D105
COMP2_Y COMP2_PB COMP2_PR COMP2_L
COMP2_R
S_VIDEO_DET
SIDE_Y
SIDE_C
+3.3V_MULTI_MST
OPT
READY
C104
30V D106
30V
D107
SD05
ZD106
SD05
ZD107
PSJ014-01
JK101
S-VIDEO
GND
6
1
C-LUG1
2
C-LUG2
3
0-SPRING
4
C-LUG3
5C-LUG4
SHIELD7
75R102 0
HOTEL_OPT R103
0
HOTEL_OPT R105
0
NON_HOTEL_OPT R106
0
HOTEL_OPT R101
75 R109 75 R108 75 R107 220K R104
12K R118 12K R117
12K R119 12K R120
10K
R113
10KR115 10KR116
220K R100
220K R111 220K R112
75 R110
75 R122
S-VIDEO
75 R121
S-VIDEO
10K
R123
100pF READY C103
10K
R114
PPJ226-01 JK100
9A [GN]1P_CAN 4A [GN]O-SPRING_A 3A [GN]CONTACT_A
9B [BL]1P_CAN 8B [BL]C-LUG_A 9C [RD]1P_CAN_1 8C [RD]C-LUG_A
9D [WH]1P_CAN 8D [WH]C-LUG_A_1
9E [RD]1P_CAN_2 4E [RD]O-SPRING_A_1 3E [RD]CONTACT_A_1
9F [YL]2P_CAN 4F [YL]O-SPRING_A 3F [YL]CONTACT_A
9G [WH]2P_CAN 8G [WH]C-LUG_A_2 9H [RD]2P_CAN 4H [RD]O-SPRING_A_2 3H [RD]CONTACT_A_2
5J[YL]O-SPRING_B 6J[YL]CONTACT_B 7K[WH]C-LUG_B 5L[RD]O-SPRING_B 6L[RD]CONTACT_B
1 9
2008/12/16
INPUT1
MSTAR N-EU
EAX56856904
H6 LCD MERCURY
POP NOISE
MNT_OUT
COMPONENT1
POP NOISE
AV1
COMPONENT1, AV1, MNT_OUT[JACK PACK TYPE D] : JK100
S-VIDEO(China Model)
INPUT1 : COMPONENT1, S-VIDEO
Copyright © 2009 LG Electronics. Inc. All right reserved.
Only for training and service purposes
LGE Internal Use Only

USB_DN USB_DP
THE SYMBOL MARK OF THIS SCHEMETIC DIAGRAM INCORPORATES SPECIAL FEATURES IMPORTANT FOR PROTECTION FROM X-RADIATION. FILRE AND ELECTRICAL SHOCK HAZARDS, WHEN SERVICING IF IS ESSENTIAL THAT ONLY MANUFATURES SPECFIED PARTS BE USED FOR THE CRITICAL COMPONENTS IN THE SYMBOL MARK OF THE SCHEMETIC.
SIDE_LIN SIDE_RIN
5.6B
ZD203
SIDE_V
PPJ218-01
JK201
5C [RD]CONTACT 2C [RD]U_CAN 4C[RD]O_SPRING 2B [WH]U_CAN 3B [WH]C_LUG 2A[YL]U_CAN 5A [YL]CONTACT 4A [YL]O_SPRING
5.6B
ZD202
USB DOWN STREAM
KJA-UB-4-0004
SIDE_USB
JK204
1234
5
IR_OUT
+3.3V_MST
TXD
4.7K R204
ST3232CDR
IC200
3
C1-
2
V+
4
C2+
1
C1+
6
V-
5
C2-
7
T2OUT
8
R2IN 9R2OUT
10 T2IN 11 T1IN 12 R1OUT 13 R1IN 14 T1OUT 15 GND 16 VCC
4.7K R205
RXD
KCN-DS-1-0088
JK200
1 2 3 4 5
6 7 8 9
10
+3.3V_MST
+5VST_MST
6630TGA004K
KCN-DS-1-0089
JK202
1
RED
2
GREEN
3
BLUE
4
GND_1
5
DDC_GND
6
RED_GND
7
GREEN_GND
8
BLUE_GND
9
NC
10
SYNC_GND
11
GND_2
12
DDC_DATA
13
H_SYNC
14
V_SYNC
15
DDC_CLOCK
16
SHILED
SD05 ZD200
DSUB_SDA
PC_VS
SD05 ZD201
ENKMC2837-T112
D211
A
AC
C
PC_B
ENKMC2837-T112
D210
A
AC
C
PEJ024-01 JK203
6B T_TERMINAL2
8SHIELD_PLATE
7B B_TERMINAL2
5T_SPRING 4R_SPRING
7A B_TERMINAL1 6A T_TERMINAL1
3E_SPRING
DSUB_SDA
PC_AUD_R
PC_G
DSUB_SCL
CAT24C02WI-GT3
IC201
3
A2
2
A1
4
VSS
1
A0
5SDA 6SCL 7WP 8VCC
ENKMC2837-T112
D212
A
AC
C
DDC_WP
PC_HS
PC_AUD_L
+5V_MULTI
DSUB_SCL
PC_R
CDS3C30GTH
30V
D202
CDS3C30GTH 30V
D203
ADUC30S03010L_AMODIODE 30V D200 ADUC30S03010L_AMODIODE 30V D201
30V D206 30V D205
ADUC30S03010L_AMODIODE
30V
D204
ADUC30S03010L_AMODIODE
30V
D209
30V
D208
READY
30V
D207
READY
USB_DL_N
USB_DL_P
0
REAR_USB
R229
0
REAR_USB
R230
USB DOWN STREAM
UB01123-4HHS-4F
JK205
REAR_USB
1234
5
0.1uF C203
0.1uF
C200
0.1uF
C201
0.1uF
C202
0.01uF C205
0.1uF C204
0.1uF C206
0.1uF C207
100R202 100R203
75 R227
220K R223
READY
220K R222
READY
12K R226
12K R228
75
R211
75
R212
75
R213
4.7K
R214
4.7K
R215
220K
R231
220K
R232
10K
R233
10K
R234
12K R235 12K R236
4.7K R220 4.7K
R221
100 R216 100 R217 100 R218
0.1uF OCP_READY C208
MIC2009YM6-TR
OCP_READYIC202
3ENABLE 2GND
4 FAULT/
1VIN6 VOUT
5ILIMIT
10uF OCP_READY C209
120OHM
OCP_READY
L200
+5V_USB
1K OCP_READY R209
4.7K OCP_READY R210
0
Non_OCP
R237
10uF 6.3VC210
USB_DL_N
USB_DL_P
68 R207 68 R208
68pF C213
68pF C211
4.7K R219
READY
0
R200
0 R201
500L201
220uF
16VC212
100uF 16V
C214
KDS226
D213
OCP_READY
A
AC
C
510 OCP_READY R238
160
OCP_READY
R206
10K
R224
10K
R225
IR_OUT
2 9
INPUT2
MSTAR N-EU 2008/12/16
INPUT2 : PC,RS-232C,SIDE AV,USB
USB
EAX56856904
H6 LCD MERCURY
Itís possibel to 27~47ohm
** 1A Design
SIDE AV
RS-232C (CI ITEM)
PC EDID PC PC SOUND
Pin to Pin with
EAN43439401
Close to SIDE_USB
Copyright © 2009 LG Electronics. Inc. All right reserved.
Only for training and service purposes
LGE Internal Use Only