LG 42LD550-UB User manual

LCD TV
SERVICE MANUAL
CAUTION
BEFORE SERVICING THE CHASSIS,
READ THE SAFETY PRECAUTIONS IN THIS MANUAL.
CHASSIS : LA02B
MODEL : 42LD550 42LD550-UB
North/Latin America http://aic.lgservice.com
Europe/Africa http://eic.lgservice.com
Asia/Oceania http://biz.lgservice.com
Internal Use Only
Printed in KoreaP/NO : MFL62863211 (1001-REV00)

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Only for training and service purposes - 2 -
CONTENTS
CONTENTS .............................................................................................. 2
SAFETY PRECAUTIONS ......................................................................... 3
SPECIFICATION....................................................................................... 6
ADJUSTMENT INSTRUCTION .............................................................. 10
EXPLODED VIEW .................................................................................. 18
SVC. SHEET ...............................................................................................

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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 1MΩand 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
IMPORTANT SAFETY NOTICE
0.15uF

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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

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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.

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Only for training and service purposes
1. Application range
This spec sheet is applied all of the 32”,42”,46”, 47”, 52”, 55”,
60” LCD TV with LA02B chassis.
2. Requirement for Test
Each part is tested as below without special appointment.
1) Temperature: 25±5ºC, (77°±9ºF), CST: 40±5°C
2) Relative Humidity: 65±10%
3) Power Voltage : Standard input voltage(100-240V~, 50/60Hz)
* Standard Voltage of each product 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 20 minutes prior to
the adjustment.
3. Test method
1) Performance: LGE TV test method followed
2) Demanded other specification
- Safety : UL, CSA, IEC specification
- EMC: FCC, ICES, IEC specification
Model Market Appliance
32LD550-UA North America Safety : UL1492, CSA C22.2.No.1,
42LD550-UA EMC : FCC Class B, IEC Class B
46LD550-UA
52LD550-UA
60LD550-UA
47LD650-UA
55LD650-UA
- 6 -
SPECIFICATION
NOTE : Specifications and others are subject to change without notice for improvement.
4. General Specification(TV)
No Item Specification Remark
1 Receivable System 1) ATSC / NTSC-M
2 Available Channel VHF : 02 ~ 13
UHF : 14 ~ 69
DTV : 02 ~ 69
CATV : 01 ~ 135
CADTV : 01 ~ 135
3 Input Voltage 1) AC 100 ~ 240V 50/60Hz
4 Market North America
5 Screen Size 55 inch Wide(1920 x 1080) FHD 55LD650-UA
47 inch Wide(1920 x 1080) FHD 47LD650-UA
60 inch Wide(1920 x 1080) FHD 60LD550-UA
52 inch Wide(1920 x 1080) FHD 52LD550-UA
46 inch Wide(1920 x 1080) FHD 46LD550-UA
42 inch Wide(1920 x 1080) FHD 42LD550-UA
32 inch Wide(1920 x 1080) FHD 32LD550-UA
6 Aspect Ratio 16:9
7 Tuning System FS
8 LCD Module Sha 60 FHD M120 CCFL SHARP 60LD550-UA
Sha 52 FHD M120 CCFL SHARP 52LD550-UA
Sha 46 FHD M120 CCFL SHARP 46LD550-UA
LC420WUH-SCA1 LGD(V5) 42LD550-UA
Sha 32 FHD M120 CCFL SHARP 32LD550-UA
9 Operating Environment Temp : 0 ~ 40 deg
Humidity : ~ 80 %
10 Storage Environment Temp : -20 ~ 60 deg
Humidity : -85 %

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5. Chrominance & Luminance
5.1. 42LD550-UA
No. Item Min Typ Max Unit Remarks
1 Max Luminance
Module 400 500 cd/m2
(Center 1-point / Full White Pattern) Set 360 450
2 Luminance uniformity 1.25 5point
3 Color coordinate RED X Typ. 0.636 Typ.
(Default) Y -0.03 0.335 +0.03
GREEN X 0.291
Y 0.603
BLUE X 0.146
Y 0.061
WHITE X 0.279
Y 0.292
4 Contrast ratio 990:1 1400:1
80,000:1 100,000:1
6 Color Temperature Cool Typ. 0.269 Typ. The W/B Tolerance is
-0.015 0.273 +0.015 ±0.015 for Adjustment
Medium Typ. 0.285 Typ.
-0.015 0.293 +0.015
Warm Typ. 0.313 Typ.
-0.015 0.329 +0.015

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6. Component Video Input (Y, CB/PB, CR/PR)
No Resolution H-freq(kHz) V-freq.(kHz) Pixel clock Proposed
1. 720*480 15.73 60 13.5135 SDTV ,DVD 480I
2. 720*480 15.73 59.94 13.5 SDTV ,DVD 480I
3. 720*480 31.50 60 27.027 SDTV 480P
4. 720*480 31.47 59.94 27.0 SDTV 480P
5. 1280*720 45.00 60.00 74.25 HDTV 720P
6. 1280*720 44.96 59.94 74.176 HDTV 720P
7. 1920*1080 33.75 60.00 74.25 HDTV 1080I
8. 1920*1080 33.72 59.94 74.176 HDTV 1080I
9. 1920*1080 67.500 60 148.50 HDTV 1080P
10. 1920*1080 67.432 59.94 148.352 HDTV 1080P
11. 1920*1080 27.000 24.000 74.25 HDTV 1080P
12. 1920*1080 26.97 23.976 74.176 HDTV 1080P
13. 1920*1080 33.75 30.000 74.25 HDTV 1080P
14. 1920*1080 33.71 29.97 74.176 HDTV 1080P
7. RGB Input (PC)
No Resolution H-freq(kHz) V-freq.(kHz) Pixel clock Proposed
PC DDC
1. 640*350 31.468 70.09 25.17 EGA X
2. 720*400 31.469 70.08 28.32 DOS O
3. 640*480 31.469 59.94 25.17 VESA(VGA) O
4 . 800*600 37.879 60.31 40.00 VESA(SVGA) O
5. 1024*768 48.363 60.00 65.00 VESA(XGA) O
6. 1280*768 47.776 59.87 79.50 CVT(WXGA) X
7. 1360*768 47.712 60.015 85.50 VESA(WXGA) X
8. 1280*1024 63.981 60.020 108.00 VESA(SXGA) O
9. 1920*1080 66.587 59.934 148.5 HDTV 1080P O

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8. HDMI input (PC/DTV)
No Resolution H-freq(kHz) V-freq.(kHz) Pixel clock Proposed
PC DDC
1. 640*350 31.468 70.09 25.17 EGA X
2. 720*400 31.469 70.08 28.32 DOS O
3. 640*480 31.469 59.94 25.17 VESA(VGA) O
4 . 800*600 37.879 60.31 40.00 VESA(SVGA) O
5. 1024*768 48.363 60.00 65.00 VESA(XGA) O
6. 1280*768 47.776 59.870 79.50 CVT(WXGA) X
7. 1360*768 47.712 60.015 85.50 VESA(WXGA) X
8. 1280*1024 63.981 60.020 108.00 VESA(SXGA) O
9. 1920*1080 67.5 60 148.5 HDTV 1080P O
DTV
1 720*480 31.50
2 720*480 31.47 59.94 27.00 SDTV 480P
3 1280*720 45.00 60.00 74.25 HDTV 720P
4 1280*720 44.96 59.94 74.176 HDTV 720P
5 1920*1080 33.75 60.00 74.25 HDTV 1080I
6 1920*1080 33.72 59.94 74.176 HDTV 1080I
7 1920*1080 67.500 60 148.50 HDTV 1080P
8 1920*1080 67.432 59.939 148.352 HDTV 1080P
9 1920*1080 27.000 24.000 74.25 HDTV 1080P
10 1920*1080 26.97 23.976 74.176 HDTV 1080P
11 1920*1080 33.75 30.000 74.25 HDTV 1080P
12 1920*1080 33.71 29.97 74.176 HDTV 1080P

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ADJUSTMENT INSTRUCTION
1. Application range
This spec. sheet applies to LA02B Chassis applied LCD TV
all models manufactured in TV factory
2. Specification
2.1 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.
2.2 AdjThe 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.
2.4 The input voltage of the receiver must keep
100~240V, 50/60Hz.
2.5 The receiver must be operated for about 5 minutes
prior to the adjustment when module is in the
circumstance of over 15
In case of keeping module is in the circumstance of
0°C, it should be placed in the circumstance of above
15°C for 2 hours
In case of keeping module is in the circumstance of
below -20°C, it should be placed in the circumstance of
above 15°C for 3 hours,.
Caution) When still image is displayed for a period of 20
minutes or longer (especially where W/B scale is
strong. Digital pattern 13ch and/or Cross hatch
pattern 09ch), there can some afterimage in the
black level area.
3. Adjustment items
3.1 Main PCB check process
• Adjust 480i Comp
• Adjust 1080p Comp
• Adjust RGB
Above adjustment items can be also performed in Final
Assembly if needed. Both Board-level and Final assembly
adjustment items can be check using In-Star Menu 1.ADJUST
CHECK.
3.2 Final assembly adjustment
• EDID/DDC download
• White Balance adjustment
• RS-232C functionality check
• Factory Option setting per destination
• Ship-out mode setting (In-Stop)
3.3 Etc
• Ship-out mode
• Tool option menu
• USB Download(S/W Update, Option, Service only)
4. Automatic Adjustment
4.1. ADC Adjustment
(1) Overview
ADC adjustment is needed to find the optimum black level
and gain in Analog-to-Digital device and to compensate
RGB deviation.
(2) Equipment & Condition
1) Jig (RS-232C protocol)
2) MSPG-925 Series Pattern Generator(MSPG-925FA)
- Resolution : 480i Comp1 (MSPG-925FA: model-209,
pattern-65)
- Resolution : 1024*768 RGB (Inner Pattern)
- Pattern : Horizontal 100% Color Bar Pattern
- Pattern level : 0.7±0.1 Vp-p
(3) Adjustment
1) Adjustment method
- Using RS-232, adjust items listed in 3.1 in the other
shown in “4.1.3.3”
2) Adj. protocol
Ref.) ADC Adj. RS232C Protocol_Ver1.0
3) Adj. order
- aa 00 00 [Enter ADC adj. mode]
- xb 00 40 [Change input source to Component1(No
action)]
- ad 00 10 [Adjust 480i Comp1]
- ad 00 10 [Adjust 1080p Comp1]
- xb 00 60 [Change input source to RGB(No action)]
- ad 00 10 [Adjust 1080p RGB]
- ad 00 90 End adj.
Protocol Command Set ACK
Enter adj. mode aa 00 00 a 00 OK00x
Source change xb 00 40 b 00 OK40x (Adjust 480i Comp1 )
(Adjust 1080p Comp1)
xb 00 60 b 00 OK60x (Adjust 1080p RGB)
Begin adj. ad 00 10
Return adj. result OKx (Case of Success)
NGx (Case of Fail)
Read adj. data (main) (main : component1 480i, RGB 1080p)
ad 00 20 000000000000000000000000007c007b006dx
(sub) (main : component1 1080p)
ad 00 21 000000070000000000000000007c00830077x
Confirm adj. ad 00 99 NG 03 00x (Fail)
NG 03 01x (Fail)
NG 03 02x (Fail)
OK 03 03x (Success)
End adj. aa 00 90 a 00 OK90x

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4.2 MAC Address and ESN Key Write
4.2.1 Equipment & Condition
• Play file: Serial.exe
• MAC Address edit
• Input Start / End MAC address
4.2.2 Download method
4.2.2.1 Communication Prot connection
Connect: PCBA Jig-> RS-232C Port== PC-> RS-232C Port
4.2.2.2 MAC Address Download
• Com 1,2,3,4 and 115200(Baudrate)
• Port connection button click(1)
• Load button click(2) for MAC Address write.
• Start MAC Address write button(3)
• Check the OK Or NG
4.2.2.3 Input the ESN Key
• download Model sending Key file
• input by 1 by SET so as not to be duplicated
4.3 LAN PORT + ESN INSPECTION (Automatic IP)
4.3.1 Equipment & Condition
• Each other connection to LAN Port of IP Hub and Jig
4.3.2 LAN inspection solution
• LAN Port connection with PCB
• Network setting at MENU Mode of TV
• setting automatic IP
• Setting state confirmation
- If automatic setting is finished, you confirm IP and MAC
Address.
4.3.3 ESN Key confirmation
• confirm Key input Data at ESN MENU Mode
PCBA PC(RS-232C)
RS-232C Port

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4.4 LAN PORT INSPECTION(PING TEST)
4.4.1. Equipment setting
1) Play the LAN Port Test PROGRAM.
2) Input IP set up for an inspection to Test
Program.
*IP Number : 12.12.2.2
4.4.2. LAN PORT inspection (PING TEST)
1) Play the LAN Port Test Program.
2) connect each other LAN Port Jack.
3) Play Test (F9) button and confirm OK Message.
4) remove LAN CABLE
5. EDID (The Extended Display
Identification Data) / DDC (Display
Data Channel) download
5.1 Overview
It is a VESA regulation. A PC or a MNT will display an
optimal resolution through information sharing without any
necessity of user input. It is a realization of “Plug and Play”.
5.2 Equipment
• Adjust remocon.
• Since embedded EDID data is used, EDID download JIG,
HDMI cable and D-sub cable are not need.
5.3 Download method
1) Press Adj. key on the Adj. R/C,
2) Select EDID D/L menu.
3) By pressing Enter key, EDID download will begin
4)If Download is successful, OK is display, but If
Download is failure, NG is displayed.
5) If Download is failure, Re-try downloads.
•Caution) When EDID Download, must remove RGB/HDMI
Cable.

- 13 -
5.4 EDID DATA
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- 14 -
5.5. White Balance Adjustment
(1) Overview
• W/B adj. Objective & How-it-works
- Objective: To reduce each Panel’s W/B deviation
- How-it-works: When R/G/B gain in the OSD is at 192, it
means the panel is at its Full Dynamic
Range. In order to prevent saturation of
Full Dynamic range and data, one of
R/G/B is fixed at 192, and the other two is
lowered to find the desired value.
- Adj. condition : normal temperature
1) Surrounding Temperature: 25±5ºC
2) Warm-up time: About 5 Min
3) Surrounding Humidity: 20% ~ 80%
(2) Equipment
1) Color Analyzer: CA-210 (NCG: CH 9 / WCG: CH12)
2) Adj. Computer(During auto adj., RS-232C protocol is
needed)
3) Adjust Remocon
4) Video Signal Generator MSPG-925F 720p/216-Gray
(Model:217, Pattern:78)
-> Only when internal pattern is not available
• Color Analyzer Matrix should be calibrated using CS-1000
(3) Equipment connection MAP
(4) Adj. Command (Protocol)
1) RS-232C Command used during auto-adj.
Ex) wb 00 00 -> Begin white balance auto-adj.
wb 00 10 -> Gain adj.
ja 00 ff -> Adj. data
jb 00 c0
...
...
wb 00 1f -> Gain adj. complete
*(wb 00 20(start), wb 00 2f(end)) -> Off-set adj.
wb 00 ff -> End white balance auto adj.
2) Adjustment Map
Applied Model : LA02B Chassis ALL MODELS
(5) Auto adj. method
1) Set TV in adj. mode using POWER ON key
2) Zero calibrate probe then place it on the center of the
Display
3) Connect Cable(RS-232C)
4) Select mode in adj. Program and begin adj.
5) When adj. is complete (OK Sing), check adj. status pre
mode (Warm, Medium, Cool)
6) Remove probe and RS-232C cable to complete adj.
* W/B Adj. must begin as start command “wb 00 00” , and
finish as end command “wb 00 ff”, and Adj. offset if need
(6) Manual adj. method
1) Set TV in Adj. mode using POWER ON
2) Zero Calibrate the probe of Color Analyzer, then place
it on the center of LCD module within 10cm of the
surface..
3) Press ADJ key -> EZ adjust using adj. R/C > 6. White-
Balance then press the cursor to the right (KEYG).
(When KEY(G) is pressed 216 Gray internal pattern
will be displayed)
4) One of R Gain / G Gain / B Gain should be fixed at
192, and the rest will be lowered to meet the desired
value.
5) Adj. is performed in COOL, MEDIUM, WARM 3 modes
of color temperature.
- If internal pattern is not available, use RF input. In EZ
Adj. menu 6.White Balance, you can select one of 2
Test-pattern: ON, OFF. Default is inner(ON). By
selecting OFF, you can adjust using RF signal in 216
Gray pattern.
LGE Internal Use OnlyCopyright LG Electronics. Inc. All right reserved.
Only for training and service purposes
Color Analyzer
Computer
Pattern Generator
RS-232C
RS-232C
RS-232C
Probe
Signal Source
* If TV internal pattern is used, not needed
Connection Diagram of Automatic Adjustment
RS-232C COMMAND Meaning
[CMD ID DATA]
wb 00 00 Begin White Balance adj.
wb 00 ff End White Balance adj.(Internal pattern disappeared)
ITEM Command Data Range Default
(Hex.) (Decimal)
Cmd 1 Cmd 2 Min Max
Cool R-Gain j g 00 C0
G-Gain j h 00 C0
B-Gain j i 00 C0
R-Cut
G-Cut
B-Cut
Medium R-Gain j a 00 C0
G-Gain j b 00 C0
B-Gain j c 00 C0
R-Cut
G-Cut
B-Cut
Warm R-Gain j d 00 C0
G-Gain j e 00 C0
B-Gain j f 00 C0
R-Cut
G-Cut

- 15 -
* Adj. condition and cautionary items
1) Lighting condition in surrounding area
Surrounding lighting should be lower 10 lux. Try to
isolate adj. area into dark surrounding.
2) Probe location
- LCD: Color Analyzer (CA-210) probe should be
within 10cm and perpendicular of the module
surface (80°~ 100°)
3) Aging time
- After Aging Start, Keep the Power ON status during 5
Minutes.
- In case of LCD, Back-light on should be checked
using no signal or Full-white pattern.
(7) Reference (White Balance Adj. coordinate and color
temperature)
•Luminance: 216 Gray
•Standard color coordinate and temperature using CS-
1000 (over 26 inch)
•Standard color coordinate and temperature using CA-
210(CH 14)
5.4. HDCP (High-Bandwidth Digital
Contents Protection) SETTING
- HDCP setting is not necessary in This Chassis.
5.5 Option selection per country
(1) Overview
- Option selection is only done for models in Non-USA
North America due to rating
-Applied model: LA92A Chassis applied None USA
model(CANADA, MEXICO)
(2) Method
1) Press ADJ key on the Adj. R/C, then select Country
Group Menu
2) Depending on destination, select KR or US, then on the
lower Country option, select US, CA, MX. Selection is
done using +, - KEY
5.6. Tool Option selection
•Method: Press Adj. key on the Adj. R/C, then select Tool
option.
•After final inspection, press In-Stop key of the Adj. R/C and
check that the unit goes to Stand-by mode.
•After final inspection, Always turn on the Mechanical S/W.
LGE Internal Use OnlyCopyright LG Electronics. Inc. All right reserved.
Only for training and service purposes
Mode Color Coordination Temp ∆UV
xy
COOL 0.269 0.273 13000K 0.0000
MEDIUM 0.285 0.293 9300K 0.0000
WARM 0.313 0.329 6500K 0.0000
Mode Color Coordination Temp ∆UV
xy
COOL 0.269±0.002 0.273±0.002 13000K 0.0000
MEDIUM 0.285±0.002 0.293±0.002 9300K 0.0000
WARM 0.313+0.002 0.329±0.002 6500K 0.0000
Model Tool 1 Tool 2 Tool 3 Tool 4 Tool5
Menu
32LD550 16460 31831 56332 4398 34
4 HDMI, CAN Tuner, 2 COMP , 2AV (REAR /SIDE)
42LD550 24640 31831 56332 4398 34
4 HDMI, CAN Tuner, 2 COMP , 2AV (REAR /SIDE)
46LD550 28748 31831 56332 4398 34
4 HDMI, CAN Tuner, 2 COMP , 2AV (REAR /SIDE)
52LD550 41036 31831 56332 4398 35
4 HDMI, CAN Tuner, 2 COMP , 2AV (REAR /SIDE)
60LD550 49228 31831 56332 4398 35
4 HDMI, CAN Tuner, 2 COMP , 2AV (REAR /SIDE)

- 16 -
6. GND and Internal Pressure check
6.1. Method
1) GND & Internal Pressure auto-check preparation
- Check that Power Cord is fully inserted to the SET.
(If loose, re-insert)
2) Perform GND & Internal Pressure auto-check
- Unit fully inserted Power cord, Antenna cable and A/V
arrive to the auto-check process.
- Connect D-terminal to AV JACK TESTER
- Auto CONTROLLER(GWS103-4) ON
- Perform GND TEST
- If NG, Buzzer will sound to inform the operator.
- If OK, changeover to I/P check automatically.
(Remove CORD, A/V form AV JACK BOX)
- Perform I/P test
- If NG, Buzzer will sound to inform the operator.
- If OK, Good lamp will lit up and the stopper will allow the
pallet to move on to next process.
6.2. Checkpoint
•TEST voltage
- GND: 1.5KV/min at 100mA
- SIGNAL: 3KV/min at 100mA
•TEST time: 1 second
•TEST POINT
- GND TEST = POWER CORD GND & SIGNAL CABLE
METAL GND
- Internal Pressure TEST = POWER CORD GND & LIVE &
NEUTRAL
•LEAKAGE CURRENT: At 0.5mArms
7. Audio
Measurement condition:
1. RF input : Mono, 1KHz sine wave signal, 100%
Modulation
2. CVBS, Component : 1KHz sine wave signal 0.4Vrms
3. RGB PC : 1KHz sine wave signal 0.7Vrms
8. Etc
LGE Internal Use OnlyCopyright LG Electronics. Inc. All right reserved.
Only for training and service purposes
No Item Min Typ Max Unit
1.
Audio practical max
9.0 10.0 12.0 W EQ Off
Output, L/R AVL Off
(Distortion=10% 8.5 8.9 9.8 Vrms Clear
max Output) Voice Off
2. Speaker (8ΩTDB TDB W EQ On
Impedance) AVL On
Clear
Voice On
Power Status
Main B/D Shipping Condition
AC Swithch condtion
Chassis Module Assembly ON N/A
Front Module Assembly N/A OFF
Factory incoming ON OFF
Final Assembly ON ON
Ship-Out OFF ON

- 17 -
7. USB S/W Download (option)
(1) Put the USB Stick to the USB socket
(2) Automatically detecting update file in USB Stick
- If your downloaded program version in USB Stick is Low,
it didn’t work.
But your downloaded version is High, USB data is
automatically detecting
(3) Show the message “Copying files from memory”
(4) Updating is staring.
(5) Updating Completed, The TV will restart automatically
(6) If your TV is turned on, check your updated version and
Tool option. (explain the Tool option, next stage)
* If downloading version is more high than your TV have,
TV can lost all channel data. In this case, you have to
channel recover. if all channel data is cleared, you didn’t
have a DTV/ATV test on production line.
* After downloading, have to adjust TOOL OPTION again.
1) Push "IN-START" key in service remote controller.
2) Select "Tool Option 1" and Push “OK”button.
3) Punch in the number. (Each model has their number.)
LGE Internal Use OnlyCopyright LG Electronics. Inc. All right reserved.
Only for training and service purposes

LGE Internal Use OnlyCopyright LG Electronics. Inc. All right reserved.
Only for training and service purposes - 18 -
300 200 800 520
530
810
910
590
120
500
510
540
400
900
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.
09/10/xx
COMPONENT / AV REAR
1 100
GP2_BCM_ATSC
L104
270nH
REAR_AV_CVBS
11:C4
COMP2_Pr
11:D3
C135
27pF
50V
R104
470K
C127
27pF
50V
L102
270nH
R113
1K
R103
470K
C105
100pF
50V
R110
0
C134
27pF
50V
R131
10
D113
5.6V
COMP1_Pb
11:D4
D116
5.5V
D119
5.6V
R116
2.7K
D3.3V
REAR_AV_DET
9:G3
L103
270nH
D111
5.5V
REAR_AV_R_IN
10:B5
C131
1uF
25V
COMP1_Pr
11:D4
D114
5.6V
C108
100pF
50V
COMP2_R_IN
10:B5
D105
5.6V
C132
1uF
25V
R129
1K
C123
100pF
R109
0
R119
1K
C137
100pF
R125
2.7K
D108
5.6V
C130
100pF
50V
R118
0
C115
100pF
50V
JK100
PPJ237-01
DEV
5J [GN3]O-SPRING
6J [GN3]E-LUG
4J [GN3]CONTACT
7K [BL3]E-LUG-S
5K [BL3]O-SPRING
7L [RD3]E-LUG-S
5L [RD3]O-SPRING_1
5M [WH3]O-SPRING
4N [RD3]CONTACT
5N [RD3]O-SPRING_2
6N [RD3]E-LUG
6D [GN2]E-LUG
5D [GN2]O-SPRING
4D [GN2]CONTACT
7E [BL2]E-LUG-S
5E [BL2]O-SPRING
7F [RD2]E-LUG-S
5F [RD2]O-SPRING_1
5G [WH2]O-SPRING
4H [RD2]CONTACT
5H [RD2]O-SPRING_2
6H [RD2]E-LUG
6A [YL1]E-LUG
5A [YL1]O-SPRING
4A [YL1]CONTACT
5B [WH1]O-SPRING
4C [RD1]CONTACT
5C [RD1]O-SPRING
6C [RD1]E-LUG
C113
27pF
50V
D3.3V
C114
27pF
50V
D112
5.5V
R114
470K
D106
5.6V
D118
5.5V
C121
27pF
50V
R105
0
C129
27pF
50V
R108
2.7K
D3.3V
D109
5.6V
C116
1uF
25V
COMP1_L_IN
10:B5
REAR_AV_L_IN
10:B5
C101 1uF
25V
C128
27pF
50V
R123
470K
R127
0
C133
27pF
50V
D117
5.5V
R117
0
R115
470K
D115
5.6V
COMP2_DET
9:G5
C109
100pF
50V
C112
27pF
50V
COMP1_R_IN
10:B5
C124
100pF
R124
470K
L101
270nH
C117
1uF
25V
L100
270nH
COMP1_DET
9:G5
C104 1uF
25V
D104
5.6V
COMP2_L_IN
10:B5
R126
0
C120
27pF
50V
C106
47pF
50V
COMP1_Y
11:D4
C136
100pF
L105
270nH
D110
5.5V
COMP2_Pb
11:D3
C122
27pF
50V
COMP2_Y
11:D3
D107
5.5V
R107
0
R106
0
R100
0
R101
0
R102
10
COMPONENT1
COMPONENT2
AV
REAR AV
COMPONENT/AV
REAR JACK
COMPONENT2
COMPONENT1
REAR AV
COMPONENT2
COMPONENT1

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.
2 100
HDMI_POWER
09/10/xxGP2_BCM_ATSC
Q200
AO3438
DEV
EBK60752601
G
D S
R202 10K
D1.8V
C201
4.7uF
OPT
C200
4.7uF
10V
OPT
POWER_ON/OFF2_1
R201
0
R200
120K
OPT
+1.8V_HDMI
HDMI SWITCH 1.8V POWER
1.8V FOR HDMI SW
Seperated from Common sheet83
N.America & Korea only use 1.8V control