LG 32LH7000 Service Manual

							LCD TV
SERVICE MANUAL
CAUTION
BEFORE SERVICING THE CHASSIS,
READ THE SAFETY PRECAUTIONS IN THIS MANUAL.
CHASSIS : LD91D
MODEL : 32LH700032LH7000-ZA
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 Only Copyright © 2009 LG Electronics. Inc. All right reserved. 
Only for training and service purposes- 2 -
CONTENTS
CONTENTS .............................................................................................. 2
PRODUCT SAFETY ..................................................................................3
SPECIFICATION ........................................................................................6
ADJUSTMENT INSTRUCTION ...............................................................10
TROUBLE SHOOTING ............................................................................15
BLOCK DIAGRAM...................................................................................19
EXPLODED VIEW .................................................................................. 20
SVC. SHEET  ...............................................................................................
 
						

							LGE Internal Use Only Copyright © 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 usedduring 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 checkon 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 PARTSGood 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 Only Copyright © 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 PRECAUTIONSon 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 theunit 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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Only for training and service purposes- 5 -
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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SPECIFICATION
NOTE : Specifications and others are subject to change without notice for improvement.
4. General specification 1. Application range
This specification is applied to the LCD TV used LD91D
chassis.
2. Requirement for Test
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  Remark
1 Display Screen Device  32 wide Color Display Module  LCD
2 Aspect Ratio 16:9
3 LCD Module  32” TFT LCD FHD 100Hz LGD
4 Operating Environment  Temp. : 0 ~50 deg
Humidity : 20 ~90 %
5 Storage Environment  Temp. : -20 ~60 deg
Humidity : 10 ~90 %
6 Input Voltage  AC100-240V~, 50/60Hz
7 Power consumption Power on  (White)
32” LGD Typ : 110, Max : 120 LCD(Module) + Backlight(Lamp)
8 Module Size 32” LGD 760.0(H) x 450.0(V) x 48.00mm(D) With inverter
9 Pixel Pitch 32” LGD 0.36375(H) x 0.36375(V)
10 Backlight   16 EEFL
11 Display Colors 1.06B(true) colors
12 Coating 3H(Hard coating)
 
						

							5. Chroma& Brightness
(1) Module optical specification
1) Stable for approximately 60 minutes in a dark environment at 25ºC
2) Operating Ambient Humidity : Min 10, Max 90 %RH
3) Supply Voltage : 24V
4) Frame Frequency : 120Hz
(2) Chroma (PSM: Vivid, Color Temperature: Cool)
- except “RGB PC Mode PSM:Standard,Color Temperature:Medium”
**The W/B Tolerance is ±0.002 for Adjustment, but for DQA ±0.015
(3) SET Optical Feature
1) General feature
* Measurement Condition: Full white/Dynamic) -> Measure the black luminance after 30 seconds.
2) Special feature (Dynamic CR 15000:1)
- 7 -LGE Internal Use Only Copyright © 2009 LG Electronics. Inc. All right reserved. 
Only for training and service purposes
No Item  Min Typ Max Remark
1. Cool White Balance,X axis 0.274  0.276  0.278 DQA :±0.015
White Balance,Y axis  0.281   0.283   0.285 DQA :±0.015
2.  Medium White Balance,X axis  0.283  0.285  0.287  DQA :±0.015
White Balance,Y axis  0.291  0.293   0.295  DQA :±0.015
3. Warm White Balance,X axis  0.311  0.313  0.315  DQA :±0.015
White Balance,Y axis  0.327  0.329  0.331  DQA :±0.015
No  Item Min typ Max Inch Power Board P/N Remark
1 Dynamic CR 10000  15000 32” EAY58473201 HDMI 720p Full Black Pattern
(Only HDMI mode) 
No Item ModuleLuminance (min) C/R(min)
Remark
AV,COMPONENT,HDMI AV,COMPONENT,HDMI
1. 32 inch LGD 400cd/m
2900  except from the PC mode.
No. Item Specification Min. Typ. Max. Remark
1. Viewing Angle10> Right/Left/Up/Down  89/89 CR>10
89/89
2. Luminance Luminance (cd/m2) 400  500 PSM:Vivid,CSM:Cool, 
White(100IRE)
Dynamic contrast :off
Dynamic color L off
Variation 1.3 MAX /MIN
3. Contrast Ratio  CR  900  1300
4. CIE Color Coordinates White Wx Typ  0.279 Typ  PSM:Vivid,CSM:Cool,
Wy -0.03 0.292 +0.03 White(85IRE)
RED Xr 0.638 Dynamic contrast :off
Yr 0.334 Dynamic color L off
Xg 0.291
Green Yg 0.607
Xb 0.145
Blue Yb 0.062
 
						

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Only for training and service purposes
6. Component Video Input (Y, PB, PR)
NoSpecification
Remark
Resolution H-freq(kHz) V-freq(Hz)
1. 720x480 15.73  60.00  SDTV,DVD 480i
2. 720x480 15.63  59.94 SDTV,DVD 480i
3. 720x480 31.47 59.94 480p
4. 720x480 31.50  60.00 480p
5. 720x576  15.625  50.00 SDTV,DVD 625 Line
6. 720x576 31.25  50.00 HDTV 576p
7. 1280x720 45.00 50.00 HDTV 720p
8. 1280x720 44.96 59.94 HDTV 720p
9. 1280x720 45.00 60.00 HDTV 720p
10. 1920x1080 31.25 50.00 HDTV 1080i
11. 1920x1080 33.75  60.00 HDTV 1080i
12. 1920x1080 33.72  59.94 HDTV 1080i
13. 1920x1080 26.97/27  23.97/24 HDTV 1080p
14. 1920x1080 33.716/33.75 29.976/30.00 HDTV 1080p
15. 1920x1080 56.250  50 HDTV 1080p
16. 1920x1080 67.43/67.5  59.94/60 HDTV 1080p
7. RGB PC INPUT 
No Resolution H-freq(kHz) V-freq.(Hz) Pixel clock(MHz) Proposed Remark
1. 720x400 31.468 70.08  28.321
2. 640x480 31.469 59.94 25.17 VESA
37.684 75.00 31.50
3. 800x600 37.879  60.31 40.00  VESA
46.875 75.00 49.50
4. 832x624 49.725 74.55  57.283 Macintosh
5. 1024x768 48.363  60.00  65.00  VESA(XGA)
56.470 70.00  75.00
60.123 75.029 78.75
6. 1280x768  47.78  59.87  79.5  WXGA
7. 1360x768  47.72  59.8  84.75  WXGA
8. 1366x768 47.56  59.6  84.75  WXGA
9. 1280x1024  63.595  60.0  108.875  SXGA
10. 1920x1080 66.647  59.988  138.625  WUXGA
 
						

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8. HDMI Input (PC/DTV)
(1) DTV Mode
No Resolution H-freq(kHz) V-freq.(Hz) Pixel clock(MHz) Proposed Remark
1  720x480  15.734 /15.6  59.94 /60 27.00  SDTV 480I
2  720x480  31.469 /31.5  59.94 /60 27.00/27.03  SDTV 480P
3 720x576  15.625  50 27(54) SDTV 576
4 720x576  31.25 50 54  SDTV 576P
5 1280x720  37.500  50 74.25  HDTV 720P
6  1280x720  44.96 /45  59.94 /60 74.17/74.25  HDTV 720P
7  1920x1080  33.72 /33.75  59.94 /60 74.17/74.25  HDTV 1080I
8 1920x1080  28.125  50.00 74.25  HDTV 1080I
9  1920x1080  26.97 /27  23.97 /24 74.17/74.25  HDTV 1080P
10  1920x1080 33.716 /33.75 29.976 /30.00 74.25  HDTV 1080P
11 1920x1080 56.250  50 148.5  HDTV 1080P
12  1920x1080  67.43 /67.5  59.94 /60 148.35/148.50  HDTV 1080P
(2) PC Mode
No Resolution H-freq(kHz) V-freq.(Hz) Pixel clock(MHz) Proposed Remark
1 720x400 31.468 70.08 28.321  HDCP
2 640x480 31.469 59.94 25.17 VESA HDCP
37.684 75.00 31.50
3 800x600 37.879 60.31 40.00 VESA HDCP
46.875 75.00 49.50
4 832x624 49.725 74.55 57.283 Macintosh HDCP
5 1024x768 48.363  60.00 65.00 VESA(XGA) HDCP
56.470 70.00 75.00
60.123 75.029 78.75
6 1280x768  47.78  59.87  79.5  WXGA HDCP
7 1360x768  47.72  59.8  84.75  WXGA HDCP
8 1366x768  47.56 59.6  84.75  WXGA HDCP
9 280x1024  63.595  60.0  108.875  SXGA HDCP
10 1920x1080 66.647  59.988  138.625  WUXGA HDCP
 
						

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Only for training and service purposes- 10 -
ADJUSTMENT INSTRUCTION
1. Application Range
This specification sheet is applied to all of the LCD TV with
LD91D chassis.
2. Designation
1) The adjustment is according to the order which is
designated and which must be followed, according to the plan
which can be changed only on agreeing.
2) Power Adjustment: Free Voltage
3) Magnetic Field Condition: Nil.
4) Input signal Unit: Product Specification Standard
5) Reserve after operation: Above 5 Minutes (Heat Run)
Temperature : at 25±5ºC 
Relative humidity : 65±10%
Input voltage : 220V, 60Hz
6) Adjustment equipments: Color Analyzer (CA-210 or CA-
110), Pattern Generator(MSPG-925 series or Equivalent)
DDC Adjustment Jig equipment, SVC remote controller
7) Push The “IN STOP KEY” - For memory initialization.
3. Main PCB check process
* APC - After Manual-Insult, executing APC
* Boot file Download
1) Execute ISP program “Mstar ISP Utility” and then click
“Config” tab.
2) Set as below, and then click “Auto Detect” and check
“OK” message
If “Error” is displayed, Check connection between
computer, jig, and set.
3) Click “Read” tab, and then load download file (XXXX.bin)
by clicking “Read”4) Click “Connect” tab. If “Can’t ” is displayed, Check
connection between computer, jig, and set.
5) Click “Auto” tab and set as below
6) Click “Run”.
7) After downloading, check “OK” message.
* USB DOWNLOAD
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”.
          filexxx.bin 
(5) 
(7) ……….OK 
(5) 
(6) 
(3) 
fi l exxx.bin 
(1) (4) 
Please Check the Speed : 
To use speed between 
from 200KHz  to 400KHz  
Case1 : Software version up
1. After downloading S/W by USB , TV set will reboot
automatically
2. Push “In-stop” key
3. Push “Power on” key
4. Function inspection
5. After function inspection, Push “I n-stop” key.
Case2 : Function check at the assembly line
1. When TV set is entering on the assembly line, Push
“In-stop” key at first.
2. Push “Power on” key for turning it on.
-> If you push “Power on” key, TV set will recover channel
information by itself.
3. After function inspection, Push “In-stop” key.