LG 43LJ5000-UB User manual

P/NO : MFL69920605 (1612-REV00)
CHASSIS : MS3553.PB765
MODEL : 43LJ5000-UB
43LJ500M-UB
CAUTION
BEFORE SERVICING THE CHASSIS, READ THE SAFETY PRECAUTIONS IN THIS MANUAL.
LED TV
SERVICE MANUAL
Internal Use Only

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2
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Copyright ©
2017
LG Electronics. Inc. All rights reserved. LGE Internal Use Only
Only for training and service purposes
CONTENTS
CONTENTS .............................................................................................. 2
SAFETY PRECAUTIONS ........................................................................ 3
SERVICING PRECAUTIONS ................................................................... 4
SPECIFICATION ...................................................................................... 6
SOFTWARE UPDATE PROCEDURE....................................................... 8
BLOCK DIAGRAM ................................................................................. 10
EXPLODED VIEW .................................................................................. 12
DISASSEMBLE....................................................................................... 13
TROUBLE SHOOTING GUIDE .................................................. APPENDIX
ADJUSTMENT INSTRUCTION ................................................ APPENDIX

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3
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Copyright ©
2017
LG Electronics. Inc. All rights reserved. LGE Internal Use Only
Only for training and service purposes
SAFETY PRECAUTIONS
IMPORTANT SAFETY NOTICE
Many electrical and mechanical parts in this chassis have special safety-related characteristics. These parts are identified by in the
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 1 W), keep the resistor 10 mm 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 1 MΩ and 5.2 MΩ.
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
1.5 K / 10 watt resistor in parallel with a 0.15 uF 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
0.5 mA.
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

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4
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Copyright ©
2017
LG Electronics. Inc. All rights reserved. LGE Internal Use Only
Only for training and service purposes
SERVICING PRECAUTIONS
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 precau-
tions. 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 explo-
sion 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 eas-
ily 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 dam-
age 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. Alter-
natively, obtain and wear a commercially available discharg-
ing 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 expo-
sure 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 sol-
der 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 elec-
trically 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 mate-
rial to the chassis or circuit assembly into which the device will
be installed.
CAUTION: Be sure no power is applied to the chassis or cir-
cuit, and observe all other safety precautions.
8. Minimize bodily motions when handling unpackaged replace-
ment 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 suf-
ficient to damage an ES device.)
General Soldering Guidelines
1. Use a grounded-tip, low-wattage soldering iron and appropri-
ate 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 1.25 cm) 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 compo-
nent 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.

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Copyright ©
2017
LG Electronics. Inc. All rights reserved. LGE Internal Use Only
Only for training and service purposes
IC Remove/Replacement
Some chassis circuit boards have slotted holes (oblong) through
which the IC leads are inserted and then bent flat against the cir-
cuit 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 remain-
ing 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 pos-
sible 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 when-
ever 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 connec-
tions).
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 con-
nected 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.

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6
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Copyright ©
2017
LG Electronics. Inc. All rights reserved. LGE Internal Use Only
Only for training and service purposes
SPECIFICATION
NOTE : Specifications and others are subject to change without notice for improvement .
1. Application range
This specification is applied to the LED TV used
MS3553.PB765 chassis.
2. Requirement for Test
Each part is tested as below without special appointment.
1) Temperature: 25 °C ± 5 °C(77 °F ± 9 °F), CST: 40 °C ± 5 °C
2) Relative Humidity: 65 % ± 10 %
3) Power Voltage
: Standard input voltage (AC 100-240 V~, 50/60 Hz)
* 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 : CB, IEC specification
- EMC : CE, IEC/CISPR
4. Model General Specification
No. Item Specification Remarks
1Receiving System NTSC-M, ATSC
2Promramme coverage 1) VHF : 02~13
2) UHF : 14~69
3) DTV : 02-69
4) CATV : US 01~135
5) CADTV : US 01~135
3Input Voltage AC 120V~, 60Hz
4Screen Size 43 inch Wide (1920 ×1080)
5Aspect Ratio 16:9
6 Module LCM Model No. Panel Model No.
Panel Maker Resolution Frame Rate
BOEI430WU1 HV430FHB-N40 BOE FHD 60 Hz
7Component & Com-
posite Input
Component + AV Bottom : CVBS(Y), Pb, Pr
Bottom : Audio L/R
8 HDMI Input HDMI2 Side
HDMI1 Bottom
9 USB USB Side (USB 2.0)

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Copyright ©
2017
LG Electronics. Inc. All rights reserved. LGE Internal Use Only
Only for training and service purposes
5. Component Video Input (Y, Cb/Pb, C
r
/P
r
)
No.
Resolution
H
-
freq(kHz)
V
-
freq.(kHz)
1
720*480i
15.73
60.00
2
720*480p
31.50
60.00
3
1440*576i
16.63
50.00
4
720*576p
31.50
50.00
5
1280*720p
37.50
50.00
6
1280*720p
45.00
60.00
7
1920*1
080i
28.13
50.00
8 1920*1080i
33.75 60.00
9
1920*1080p
56.25
50.00
10
1920*1080p
67.50
60.00
6. HDMI Input :
No. Resolution H-freq(kHz) V-freq.(kHz)
PC(DVI)
1720*400 31.469 70
2640*480 31.469 59.940
3800*600 37.879 60.310
41024*768 48.363 60.000
5
1360*768 47.712 60.015
6
1920*1080 67.5 60
DTV
1640*480p 31.47 59.94
2640*480p 31.5 60.00
3720*480p 31.47 59.94
4720*480p 31.5 60.00
51280*720p 44.96 59.94
61280*720p 45.00 60.00
7720(1440)*480i 15.73 59.94
8720(1440)*480i 15.75 60.00
9720*576p 31.25 50.00
10 1280*720p 37.5 50.00
11 720(1440)*576i 15.63 50.00
12 1920*1080i 28.125 50.00
13 1920*1080i 33.72 59.94
14 1920*1080i 33.75 60.00
15 1920*1080p 26.97 23.976
16 1920*1080p 27.00 24.00
17 1920*1080p 33.716 29.976
18 1920*1080p 33.75 30.00
19 1920*1080p 56.25. 50.00
20 1920*1080p 67.432 59.94
21 1920*1080p 67.50 60.00

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8
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Copyright ©
2017
LG Electronics. Inc. All rights reserved. LGE Internal Use Only
Only for training and service purposes
SOFTWARE UPDATE PROCEDURE
1. USB Upgrade
1. Place the higher version software in LG_DTV folder in USB root folder, like this.
2. Plug in USB disk, then a notify OSD will be displayed if the software in LG_DTV higher than current software of TV set.
3. Select “YES” button and press “OK” key if you want to update TV software, the update OSD will be displayed.

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9
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Copyright ©
2017
LG Electronics. Inc. All rights reserved. LGE Internal Use Only
Only for training and service purposes
About the LED flash during software upgrade:
Upgrading:
Red 1000ms Green 1000ms alternates,the TV set will turn to Upgrade succeed or Upgrade Failed status after the upgrading
process.
Upgrade succeed:
Red 250ms Green 250ms alternates, flashing before power off.
Upgrade Failed:
Red 1750ms Green 250ms alternates，flashing before power off.
4. TV set will reboot after update success.
2. AC ON
In order to avoid the software which is on the mainboard can not work normal for current panel,you can upgrade the
correct software through AC ON:
1. Copy the Software Bin to the U-Disk root;
2. Insert the U-Disk to the mainboard USB Port;
3. The AC on,
4. Then the TV will upgrade, and need to reboot after upgrade success.
Upgrading:
Red 1000ms Green 1000ms alternates,the TV set will turn to Upgrade succeed or Upgrade Failed status after the
upgrading process.
Upgrade succeed:
The TV will prompt to restart immediately.After restart, The TV will prompt From what version of the TV will be
prompted to upgrade to what version.

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SYSTEM FUNCTION BLOCK DIAGRAM
YPBPR CVBS & Audio IN
Optical
MSD3553
HDMI1
HDMI2
NTSC/ATSC
I2C&AGC
VIF
USB 2.0
LVDS/miniLVDS
SPI
FLASH
AMP
TPA5733l
L
R
I2S
IR & KEY
DDR3
128MB

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11
2017
PSU
12V
UD1
DC-DC
5V_STB
MainBoardPowerTree
LC2127
5V_M
D-LDO
UL1
3V3_STB 200mA
200mA
1.15V
150mA(eff=85%)
1230mA
1800mA+PanelCurrent
MSD3553
M_I2C PIN52
PIN51
M_SCL
M_SDA
3V3_STB
UT2
Si2159
Add_R
RT1 RT2
0xC1
UD1
DC-DC
2000mA
MP9495
5V_STB
800mA(eff=90%)
1730mA
Add_W 0xC0
LVDS
Add_R
Add_W
1000mA
VCC-PANEL
TAS5733L
TBD
U1
MSD3553
150mA
U1
MSD3553
700mA
D-LDO
UL1
VCC_DDR
230mA
230mApeaUk
1
MSD3553
120mAavg
USB2.0
1000mA
500mA
8ohm 5W
POW_EN
POW_EN
800mA
D-LDO
UL1
3V3_M 270mA
270mA
UT2
Tuner
200mA
U1
TAS5733
68mA
UA1
TAS5733
Addr 0x56

EXPLODED VIEW
IMPORTANT SAFETY NOTICE
Many electrical and mechanical parts in this chassis have special safety-related characteristics. These parts are identified by in
the 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.
2017
200
400
540
901
902
120
800
521
522
LV1
AR1
ARC1
500
-12-

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3
1
1. After Screw Disassemble (Total Screw 17pcs),
please remove B/C from Module
2017

4
2
2. Remove all sort of connetcor.
2017

5
3
3. Remove Power core&IO cover&Tape
2017

6
4
4. Screw and mainboard and tape disassembly
2017

7
5
5. tape disassembly
2017

8
6
6. Remove speaker&versamount bracket &screw
2017

9
7
7. Remove IR COVER&tape
2017

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LGE Internal Use Onl
y
No. Error symptom Content Page Remarks
1 Power Supply Trouble No power A1
2 Blurred screen A2-1
3WhitescreenA2-2
4 Black screen A2-3
5 Black screen A2-4
6 Audio Trouble No sound A3
7 TV video error A4-1
8 HDMI,YPbPr,CVBS error A4-2
9 Power circuit diagram A5
10 Power supply Trouble 2 No power A6
11 Power supply for LED drive No backlight A7
12 Exchange T -Con Board (1) Appendix-1
13 Exchange T -Con Board (2) Appendix-2
14 Exchange Module itself (1) Appendix-3
15 Exchange Module itself (2) Appendix-4
16 Appendix : ADJUSTMENT INSTRUCTION ADJUSTMENT Appendix-5
Function error
Appendix:
Defected Type caused by T-Con/Module
Display Trouble
2017