LG M4224C Schematic

LCD MONITOR TV

SERVICE MANUAL

CAUTION

BEFORE SERVICING THE CHASSIS, READ THE SAFETY PRECAUTIONS IN THIS MANUAL.

CHASSIS : LW81B

MODEL : M4224C

M4224C-BAG/BAPG

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

2008

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CONTENTS

CONTENTS .............................................................................................. 2

PRECAUTIONS .........................................................................................3

SPECIFICATION........................................................................................7

TIMING CHART .......................................................................................12

ADJUSTMENT INSTRUCTION ...............................................................14

BLOCK DIAGRAM...................................................................................19

DESCRIPION OF BLOCK DIAGRAM .....................................................20

TROUBLE SHOOTING............................................................................21

EXPLODED VIEW .................................................................................. 28

SVC. SHEET ...............................................................................................

WARNING FOR THE SAFETY-RELATED COMPONENT.

• There are some special components used in LCD monitor that are important for safety. These parts are

marked on the schematic diagram and the Exploded View. It is essential that these critical parts

should be replaced with the manufacturer’s specified parts to prevent electric shock, fire or other hazard.

• Do not modify original design without obtaining written permission from manufacturer or you will void the original parts and labor guarantee.

TAKE CARE DURING HANDLING THE LCD MODULE WITH BACKLIGHT UNIT.

• Must mount the module using mounting holes arranged in four corners.

• Do not press on the panel, edge of the frame strongly or electric shock as this will result in damage to the screen.

• Do not scratch or press on the panel with any sharp objects, such as pencil or pen as this may result in damage to the panel.

• Protect the module from the ESD as it may damage the electronic circuit (C-MOS).

• Make certain that treatment person’s body are grounded through wrist band.

• Do not leave the module in high temperature and in areas of high humidity for a long time.

• The module not be exposed to the direct sunlight.

• Avoid contact with water as it may a short circuit within the module.

• If the surface of panel become dirty, please wipe it off with a softmaterial. (Cleaning with a dirty or rough cloth may damage the panel.)

WARNING

BE CAREFUL ELECTRIC SHOCK !

• If you want to replace with the new backlight (CCFL) or inverter circuit, must disconnect the AC adapter because high voltage appears at inverter circuit about 650Vrms.

• Handle with care wires or connectors of the inverter circuit. If the wires are pressed cause short and may burn or take fire.

Leakage Current Hot Check Circuit

LGE Internal Use Only

2008

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PRECAUTION

CAUTION

Please use only a plastic screwdriver to protect yourself from shock hazard during service operation.

Ω

AC Volt-meter

Good Earth Ground such as WATER PIPE,

To Instrument’s exposed METALLIC PARTS

1.5 Kohm/10W

CONDUIT etc.

When 25A is impressed between Earth and 2nd Ground for 1 second, Resistance must be less than 0.1

*Base on Adjustment standard

LGE Internal Use Only

2008

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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 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.

d. Discharging the picture tube anode.

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. Discharge the picture tube anode only by (a) first connecting one end of an insulated clip lead to the degaussing or kine aquadag grounding system shield at the point where the picture tube socket ground lead is connected, and then (b) touch the other end of the insulated clip lead to the picture tube anode button, using an insulating handle to avoid personal contact with high voltage.

4. Do not spray chemicals on or near this receiver or any of its assemblies.

5. Unless specified otherwise in this service manual, clean electrical contacts only by applying the following mixture to the contacts with a pipe cleaner, cottontipped 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.

6. Do not defeat any plug/socket B+ voltage interlocks with which receivers covered by this service manual might be equipped.

7. 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.

8. 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.

9. 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 "antistatic" 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.)

LGE Internal Use Only

2008

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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 500ºF to 600ºF.

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.

(500ºF to 600ºF) 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

circuitboard printed foil.

6. Use the following soldering technique. a. Allow the soldering iron tip to reach a normal

temperature (500ºF to 600ºF)

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.

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.

LGE Internal Use Only

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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LGE Internal Use Only

2008

1. Application Range.

This spec sheet is applied to the 42” LCD Monitor TV used LW81B chassis.

2. Specification

Each part is tested as below without special appointment

2.1 Temperature : 25±5°C(77±9°F), CST : 40±5°C

2.2 Relative Humidity : 65±10%

2.3 Power Voltage : Standard input voltage (100~240V@ 50/60Hz)

• Standard Voltage of each products is marked by models

2.4 Specification and performance of each parts are followed each drawing and specification by part number in accordance with BOM .

2.5 The receiver must be operated for about 5 minutes prior to the adjustment.

3. Test method

3.1 Performance : LGE TV test method followed.

3.2 Demanded other specification Safety : CE, IEC specification EMC : CE, IEC

SPECIFICATION

NOTE : Specifications and others are subject to change without notice for improvement

4. General Specification

No Item Content Remark

Customer

BRAND

User Model Name

M4224C

Sale region

World wide

Feature

42 Commercial AV LCD Multi Function Monitor

Chassis Name

LW81B

External SW

&Adj.

Source, Menu, , , , , Auto/Set, Power

General Scope

Function

A/V In/Out, Component(HDTV Ready)x1, RGB IN/OUT, PC Sound IN, RS232C In/out , HDMI (with HDCP), Wired Control,

DDC2B

, LAN control

8Keys

Power Cord

Length : 1.87 –0.04 M Shape : W all-out, Color : Black (GRAY)

P/No

6410TKW005A

(6410TKW005B)

Cable

Signal

Cable (D-SUB)

Length : 1.87 –0.04 M Shape : Detachable Type Color : GRAY (Black) Pin : Triple Row, 15-Position Sub -miniature D

P/No.

6850TD9007E

(6850TD9007D)

Maker Type TFT Color LCD Module Active Display Area 42.02 inches(1067.31mm) diagonal Pixel Pitch [mm] 0.4845mm(H) 0.48 45mm(V) Electrical Interface LVDS Color Depth 10bits(D), 1.06 Billion Size [mm] 956.4(H)x 549.4(V)x 53.5(D)

Surface Treatment Anti-Glare, Hard Coating (3H) Operating Mode Normally Black, Back light Unit 20 CCFL

LCD Module Feature

R/T

Typ 9ms(GTG)

P/No:EAJ51595601 (LD420WUB- SAA1)

LPL

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LGE Internal Use Only

2008

No Item Content Remark

1 Product Width (W) Length (D) Height (H)

Dimension Before Packing 967 177 656 With SPK, Stand

After Packing 1145 277 728 With SPK, Stand

2 Product Only SET T.B.D With SPK, Stand

Weight With BOX T.B.D With SPK, Stand

3 Container 20ft 40ft

Loading Individual or Indi. Wooden Indi. Wooden Quantity Palletizing 126 258

4 Stand Type Detachable

Assy Size (W x D x H) 620.1 x 68.4 x 186.4 mm

Tilt Degree Tilt force Swivel Degree Swivel Force -

5 Appearance General Refer to Standard of LG(55)G1-1020 Design Gap =1.0mm

5. Mechanical Specification

6. Special Function

No. Contents Description Remark

1 Audio Output Rating 10W+ 10W (Rated Out put ± 10%) Volume :Adjust

AMP Freq. Character 100Hz ~ 10KHz Range ( -3 dB )

T.H.D Within 10% Input Sensitivity 0.700Vrms S/N OVER 40dB

2 Speaker Type Built-in

Impedance 8 Ω Input Max : 15W, Normal : 10W

3 AV Video Level Input : 0.7±0.15 V p-p 75 Ω Terminal Resistor

Sync Level Input : 0.286±0.075 V p-p 75 Ω Terminal Resistor Color Burst Input : 0.214±0.072 V p-p 75 ΩTerminal Resistor Audio Level AV, Component Input:0.50 V rms 600 Ω

PC Input : 0.70

Video Cross Talk 43 dB

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LGE Internal Use Only

2008

7. Engineering Specification

No. SECTION CONTENTS REMARK

1. Supported Sync Type Separate Sync, SOG, Composite Sync, Digital 2 Operating Frequency Analog Horizontal 30 ~ 83 KHz

Vertical 56 ~ 75 Hz

Digital Horizontal 30 ~ 83 KHz

Vertical 56 ~ 60 Hz

3 Resolution Analog Max 1920 x 1080 @60Hz

Recommend 1920 x 1080 @60Hz

Digital Max 1920 x 1080 @60Hz

Recommend 1920 x 1080 @60Hz

4 Input Voltage Voltage : 100 ~ 240Vac , 50 or 60Hz

Current Rating 5 Inrush Current Cold : 40A , Hot : 40A 6 Operating Condition Sync (H/V) Video LED Wattage

Normal Mode(1/8 point of

Normal (Typ) On/On Active Green 220W

max audio output) Sleep Mode Stand by Off/On Off Amber 1W RGB (Set = On) ( G Signal should be off) Off/On Off Amber 4W HDMI (Signal=Off) Suspend On/Off Off Amber 1W RGB

( G Signalshould be off) On/Off Off Amber 4W HDMI DPMS Off Off/Off Off Amber 1W RGB ( G Signal should be off) Off/Off Off Amber 4W HDMI

Deep Sleep Mode

Power SW Off Off/Off Off Off 1W

(Set = Off)

7 MTBF 50,000 HRS with 90%Lamp Life

Confidence level :50,000 Hours (min) 8 Using Altitude 5,000 m (for Reliability) 3,000 m (for FOS) 9 Environment Operating Temperature 5 °C ~ 35 °C

Condition Humidity 10% ~ 80%

Storage Temperature -20 °C ~ 60 °C non condensing

Humidity 5% ~ 95% non-condensing

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LGE Internal Use Only

2008

8. Optical Characteristic

8.1 Optical Characteristic

No Item Criteria Remark

1 Viewing Angle Horizontal(R/L) : +89º/-89º (Min.)

<CR ≥10> Vertical(Top/Bottom) : +89º/-89º (Min.)

2 Luminance Luminance (cd/m 2 ) 550 cd/m2 (min.) 700cd/m2 (Typ)

Condition- Picture mode : Vivid,

3 Contrast Ratio 2,500(Min.), 3,000:1(Typ.) (with DCR) All input

• Condition -Picture mode : Vivid

-It should be measured after signal input and pass through more than 30 sec

4 Grey Level Gray Level without AI with AI

L0 0.12

L15 0.22

L3 1 0.7 L47 2.28 L63 4.58 L79 7.15 L95 10.82

L111 15.72 L127 21.93 L143 27.81 L159 34.94 L175 43.32 L191 53.12 L207 63.10 L223 74.51 L239 86.99 L255 100.0

5 Light Leakage Condition: Do not visible at 300 Lux

8.2 AV / Component / HDMI / DVI INPUT MODE NO Item Min Typ Max Unit Remark

1 Brightness uniformity 77 % Full white

Color Purity RED X 0.609 0.639 0.669 Input : 216 Level

Y 0.303 0.333 0.363 Picture mode : Vivid

GREEN X 0.255 0.285 0.315

Y 0.575 0.605 0.635

BLUE X 0.114 0.144 0.174

Y 0.035 0.065 0.095

WHITE X 0.249 0.279 0.309

Y 0.262 0.292 0.322 Color WHITE X 0.261 0.276 0.291 Input : 216 Level coordinate (Cool) Y 0.268 0.283 0.298 Picture mode : User1

WHITE X 0.270 0.285 0.300 (Medium) Y 0.278 0.293 0.308 WHITE X 0.298 0.313 0.328 (Warm) Y 0.314 0.329 0.344

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LGE Internal Use Only

2008

8.3 RGB INPUT MODE NO Item Min Typ Max Unit Remark

1 Brightness uniformity 77 % Full white

Color Purity RED X 0.609 0.639 0.669 Input : 255 Level

Y 0.303 0.333 0.363 Picture mode : Standard

GREEN X 0.255 0.285 0.315

Y 0.575 0.605 0.635

BLUE X 0.114 0.144 0.174

Y 0.035 0.065 0.095

WHITE X 0.249 0.279 0.309

(Before) Y 0.262 0.292 0.322 Color WHITE X 0.261 0.276 0.291 coordinate (After) Y 0.268 0.283 0.298

* Standard Measurement Condition

• Ambient Luminance Level : dark ( < 10 lux)

• Ambient Temperature : Normal Temperature( 25+/- 2 °C)

• warm-up Time : About 30min (at Full White Pattern)

• Input Signal : V Frequency 60Hz, Dclk 65MHz

• Contrast : Default Value (100)

• Brightness : Default Value(64)

• 6500K : Color Temperature Setting is 6500 K( if it’s not special specification)

• Clock/Clock Phase : The Best Setting

* Another Spec.: Product Specification Standard( LG(55)G1-1034 ) * Cosmetic Spec. : LCD Module IIS Spec.

8.4 Display Area

8.4.1 Active Display Area of the LCD Monitor Should be within Cabinet’s Bezel .

8.4.2 Distance Difference between Active Area and Bezel | A-B|< 1.5 mm , | C-D|< 1.5 mm A: The Distance from The Left of Active Area to the Bezel B: The Distance from The Right of Active Area to the Bezel C: The Distance from The Top of Active Area to the Bezel D: The Distance from The Bottom of Active Area to the Bezel

Active Area

Bezel

TIMING CHART

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LGE Internal Use Only

2008

1. PC Mode(RGB Input)

MODE SECTION POLA DOT CLOCK Frequency TOTAL Display Front Sync. Back RESOLUTION

RITY [MHz] [kHz]/[Hz] CYCLE (E) [A] Porch[B] [D] Porch[F]

1 H(Pixels) + 25.175 31.469 800 640 16 96 48 640 x350

V(Lines) - 70.8 449 350 37 2 60

2 H(Pixels) - 28.321 31.468 900 720 18 108 54 720 X400

V(Lines) + 70.8 449 400 12 2 35

3 H(Pixels) - 25.175 31.469 800 640 16 96 48 640 x480

V(Lines) - 59.94 525 480 10 2 33

4 H(Pixels) - 31.5 37.5 840 640 16 64 120 640 x480

V(Lines] - 75 500 480 1 3 16

5 H(Pixels) + 40.0 37.879 1056 800 40 128 88 800 x600

V(Lines) + 60.317 628 600 1 4 23

6 H(Pixels) + 49.5 46.875 1056 800 16 80 160 800 x600

V(Lines) + 75.0 625 600 1 3 21

7 H(Pixels) +/- 57.283 49.725 1152 832 32 64 224 832 x624

V(Lines) +/- 74.55 667 624 1 3 39

8 H(Pixels) - 65.0 48.363 1344 1024 24 136 160 1024 x768

V(Lines) - 60.0 806 768 3 6 29

9 H(Pixels) - 78.75 60.123 1312 1024 16 96 176 1024 x768

V(Lines) - 75.029 800 768 1 3 28

10 H(Pixels) + 74.5 44.772 1664 1280 64 128 192 1280 x720

V(Lines) + 59.855 748 720 3 5 20

11 H(Pixels) + 80.14 47.7 1680 1280 64 136 200 1280 x768

V(Lines) + 60 795 768 1 3 23

12 H(Pixels) + 84.75 47.72 1776 1360 72 136 208 1360 x768

V(Lines) + 59.799 798 768 3 5 22

13 H(Pixels) - 85.86 47.7 1800 1366 72 144 216 1366 x768

V(Lines) - 60 795 768 1 3 23

14 H(Pixels) - 108.0 63.981 1688 1280 48 112 248 1280 x1024

V(Lines) - 60.02 1066 1024 1 3 38

15 H(Pixels) - 135.00 79.98 1688 1280 16 144 248 1280 x1024

V(Lines) - 75.02 1066 1024 1 3 38

16 H(Pixels) - 146.25 65.290 2240 1680 104 176 280 1680 x1050

V(Lines) - 59.954 1089 1050 3 6 30

17 H(Pixels) - 148.5 67.5 2200 1920 88 44 88 1920 x1080

V(Lines) - 60 1125 1080 4 5 46

+ 26 hidden pages