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LG TRAINING MANUALFall 2008 LCD TrainingLG TRAINING MANUAL

32LG40


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IMPORTANT SAFETY NOTICE

This manual was prepared for use only by properly trained audio-visual service technicians. When servicing this product, under no circumstancesshould the original design be modified or altered without permission from LG Electronics. Unauthorized modifications will not only void the

Published July 2008 by LG Electronics USA Training Center

Copyright © 2008 LG Electronics of Alabama, Inc.

Contact Number Hours of Operation

Customer Service (800) 243-0000 24 hours a day / 7 days a week

Technical Support (800) 847-7597 7am-7pm Mon-Fri / Sat 8-2 CT

Parts Sales (888) 393-6484 7am-7pm Mon-Sat CT

Training Center (256) 774-4051 8am-5pm Mon-Fri CT

WEB CONTACTS:

Web Site Address Description

LG USA www.lgusa.com Product information

Customer Service us.lgservice.com User manuals, FAQs

GCSC aic.lgservice.com Service manuals, parts, bulletins

Customer Service Academy www.lgcsacademy.com Web training, discussion forum

Live Training lge.webex.com Live training

PHONE CONTACTS:


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TABLE OF CONTENTS

OVERVIEW .................................................. 5Introduction ....................................................5

Basic Troubleshooting Steps ............................5

Caution............................................................5

Model Number Structure ...............................6

Serial number Structure ..................................6

Features ..........................................................7

32LG40 Dimensions ........................................8

42LG60 Dimensions ........................................8

Remote Control ..............................................9

New Features .................................................9

Computer Connection ................................. 10Service Menu................................................ 10

Power Consumption .................................... 10

Service Remote ............................................ 11

Check Firmware Version ............................. 12

Update Firmware ......................................... 12

DISASSEMBLY - 32LG40 ............................ 13Back Cover Removal .................................... 13

Board Layout ................................................ 13

Power Supply Removal ................................ 14Main Board Removal .................................... 14

LCD Driver Removal ................................... 15

Ballast Removal ............................................ 16

DVD Player Removal ................................... 17

DVD Player Removal ................................... 17

Exploded View ............................................. 18

CIRCUIT DESCRIPTIONS - 42LG60 ......... 45Introduction ................................................. 45

Backlight Layout ........................................... 46

Power Supply Layout ................................... 47

Control Board Layout .................................. 49

LCD Driver (T-CON) Layout ...................... 51

Main board layout ........................................ 53

Invisible Speaker SyStem Layout .................. 61

SCHEMATICS ............................................ 6332LG40 :: Interconnect ................................ 63

32LG40 :: WaveForms ................................. 64

32LG40 :: Main Board :: Main Micro ............ 6532LG40 :: Main Board :: Audio .................... 66

32LG40 :: Main Board :: Memory ................ 67

32LG40 :: Main Board :: BCM/USB.............. 68

32LG40 :: Main Board :: DCM ..................... 69

32LG40 :: Main Board :: LVDS/DVD ............ 70

32LG40 :: Main Board :: Tuner Power ......... 71

32LG40 :: Main Board :: Jackpacks ............... 72

32LG40 :: Main Board :: HDMI .................... 73

42LG60 :: Interconnect ................................ 7442LG60 :: Waveforms .................................. 75

42LG60 :: Main Board :: BCM ..................... 76

42LG60 :: Main Board :: DDR Memory ...... 77

42LG60 :: Main Board :: Main Micro ........... 78

42LG60 :: Main Board :: Audio Processor .. 79

42LG60 :: Main Board :: HDMI ................... 80


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OVERVIEW

OVERVIEW 2008 LCDS

INTRODUCTIONThe manual covers two models from the 2008 LCD product line. Each model is an HDTVwith integrated HD tuner. The 32LG40 is a 720p/1080i model, the 42LG60 supports1080p (Full HD). All models 32” and larger include USB Media Host and SimpLink. USBMedia Host consists of a USB port on the back of the TV that supports USB flash memorydrives loaded with media or firmware for the TV. SimpLink allows for control of other LG

SimpLink products via the HDMI connection.All LCD TV models are module level repair in and out of warranty. They are covered by aone year parts and labor warranty. Refer to the last page of the owner’s manual for morewarranty information. For models under 30”, the Sevice Level is Factory Service Repair.Larger models are Field Service. Contact the Warranty department for more information.

BASIC TROUBLESHOOTING STEPSDefine - Look at the symptom carefully and determine what circuits could be causing the

failure. Use your senses Sight, Smell, Touch and Hearing. Look for burned parts andcheck for possible overheated components. Capacitors will sometimes leak dielectricmaterial and give off a distinct odor. Frequency of power supplies will change withthe load or listen for relay closing etc Observation of the front Power LED may give


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OVERVIEW

MODEL NUMBER STRUCTURE

4 2 L G 6 0 - U A

Region

U = North America

B = Europe & NA

Chassis Version

3) Be cautious of electric shock from the Backlight section, it uses high voltage AC. Checkthat the Power Supply and Drive Circuits are completely discharged because of residualcurrent stored before circuit board removal.

4) C-MOS circuits are sensitive to static electricity. Use caution when dealing with theseIC and circuits.

5) Exercise care when making voltage and waveform checks to prevent costly short circuitsfrom damaging the unit.

6) Be cautious of lost screws and other metal objects to prevent a possible short in the

circuitry.

7) Check the appearance of the Replacement Panel and Circuit boards for both physicaldamage and part number accuracy. Verify model names and board model matches.


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OVERVIEW

FEATURES

Model Name 32LG40 47LG60

Chassis Name LP81A LP81A

Screen Specs

Resolution 1366 x 768p 1920 x 1080p

Brightness (cd/m2) 500 500

Contrast Ratio (BareModule)

1,200:1 1,500:1

Dynamic Contrast Ratio 10,000:1 12,000:1

Viewing Angle 178/178 178/178

Colors Reproduction(R G B)

8 Bit 10 Bit

(8 Bit+Dithering)

42LG6032LG40


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OVERVIEW

32LG40 DIMENSIONS

7.9"

200mm

21.7"

551.2mm

3.9"

100mm

3.5"

89mm

11"

279mm

31.8"

808mm

9 11/16"

246.06mm

8.38"

212.74mm

Remove 4 screws to remove

stand for wall mount

Model No.

Serial No.

Side Label

12"

304.8mm

17.1"

24.8"

629.92mm

4.3"

109mm

11.8"

Not Center

Center

3.9"

100mm


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OVERVIEW

REMOTE CONTROL2008 models feature a newly designed, easier to use remote. The remotehas fewer buttons than previous designs which was accomplished bymoving many functions to an on-screen Quick Menu. The “Q. MENU”button on the remote opens the Quick Menu and the user can choosebetween options like aspect ratio, closed captions, sleep timer, etc.

The remotes are programmable for other devices. These LCDs alsosupport SimpLink devices. When using SimpLink, the device buttons

on the remote do not need to be pressed to switch modes beforecontrolling external equipment. External devices are controlled by theTV instead of the remote.

NEW FEATURESBelow are some of the new features on some 2008 LCD TVs.

Intelligent sensor - LG’s “Intelligent Sensor” uses 4,096 sensing stepsto evaluate its surroundings. Using a sophisticated algorithm, the LGprocesses picture quality elements including brightness, contrast,color, sharpness and white balance. The result is a picture optimizedfor its surroundings, more pleasing to watch. It can also save up to

INPUT

FAV

MUTE

TV

STB

POWER

Q. MENU MENU

AV MODERETURN

ENTER

VOL CH

1 2 3

4 5 6

7 8 9

P AGE

DVD

VCR


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OVERVIEW

COMPUTER CONNECTIONA computer can be connected to the RGB(VGA) or HDMI connection on the TV. TheHDMI connection will require a DVI to HDMIadapter if the PC has a DVI connector.

Set the monitor output resolution and verticalfrequency on the PC before connecting it tothe TV. Refer to the owner’s manual for a full

list of suported resolutions. The message“OUT OF RANGE” will appear on the screenif the resoultion is not supported.

Model On Stand-ByTYP MAX UNIT TYP MAX UNIT

19LS4D-UA 42W 0.85 1W

20LS7D-NB 56W 0.85 1W

20LS7D-UK 56W 0.85 1W

22LC2D-UB 46W 0.85 1W

22LS4D-UA 46W 0.85 1W

23LS7D-NB 78W 0.85 1W23LS7D-UK 78W 0.85 1W

26LC7DC-UB 110 160W 0.7 1W

26LC7DC-UK 30 160W 0.7 1W

26LC7D-UK 30 160W 0.7 1W

26LG30DC-UA 99 115W 0.36 0.8W

32LC4D-UA 150 190W 0.7 1W

32LC50C-UA 190W 3W

32LC5DC-UA 190W 3W

32LC7DC-UK 170 190W 0.7 1W

32LC7D-UB 150 190W 0.7 1W

32LC7D-UK 170 190W 0.7 1W

POWER CONSUMPTION

Resolution Vertical

Frequency (Hz)

30/40/50/60/70 series

1280x768 60Hz

1360x768 60Hz

1366x768 60Hz

50/60/70 series

1600x1200 60Hz


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OVERVIEW

SERVICE REMOTE NUM KEY FUNCTION

1 POWER To turn the TV on or off

2 POWER ON To turn the TV on automatically if the power is supplied to the TV. Use the POWER key to deactivate; It

should be deactivated when delivered.

3 MUTE To activate the mute function.

4 P-CHECK To check TV screen image easily.

5 S-CHECK To check TV screen sound easily

6 ARC To select size of the main screen (Normal, Spectacle, Wide or Zoom)

7 CAPTION Switch to closed caption broadcasting

8 TXT To toggle on/off the teletext mode

9 TV/AV To select an external input for the TV screen

10 TURBO SOUND To start turbo sound

11 TURBO PICTURE To start turbo picture

12 IN-START To enter adjustment mode when manufacturing the TV sets.

To adjust the screen voltage (automatic): In-start mute Adjust AV (Enter into W/B adjustment mode).

W/B adjustment (automatic): After adjusting the screen W/B adjustment Exit two times

13 ADJ To enter into the adjustment mode. To adjust horizontal line and sub-brightness.

14 MPX To select the multiple sound mode (Mono, Stereo or Foreign language).

15 EXIT To release the adjustment mode.

16 APC(PSM) To easi ly adjust the screen according to surrounding br ightness.

17 ASC(SSM) To easily adjust sound according to the program type.

18 MULTIMIDIA To check component input.

19 FRONT-AV To check the front AV.

20 CH To move channel up/down or to select a function displayed on the screen.

21 VOL To adjust the volume or accurately control a specic function.

22 ENTER To set a specic function or complete setting.


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OVERVIEW

CHECK FIRMWARE VERSIONYou can check the firmware versionby opening the service menu. It islocated near the top of the menu.

UPDATE FIRMWARE1) Copy the firmware to the top

level on a USB flash drive and toa folder named LG_DTV. Somemodels require the LG_DTVfolder, and some don’t. Put it inboth locations if you are not surewhich is correct. Only copy thefile (or files) for the model you arecurrently updating. 2) Turn on the

TV and insert the USB drive to theUSB IN port.

3) If the firmware is newer than what is already installed, the upgrade menu should openautomatically. If the update menu doesn’t open, press MENU on the user remote andselect OPTION Now press the Fav key 7 times and the upgrade menu will open

LP81A LPL L42FHD

Main V1.62 USB V2.1400 HDCP 0

UTT 97

Tool Option1 39848

Tool Option2 51

Area Option 1

OPTION1 43

OPTION2 46

OPTION3 0

OPTION4 0

System Control

Audio Prescale

Threshold

Power Off Histor y

Panel Control

Davinci / Auto Test

LP81A LPL L42FHD

Main V1.62 USB V2.1400 HDCP 0

UTT 97

Tool Option1 39848

Tool Option2 51

Area Option 1

OPTION1 43

OPTION2 46

OPTION3 0

OPTION4 0

System Control

Audio Prescale

Threshold

Power Off Histor y

Panel Control

Davinci / Auto Test


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DISASSEMBLY

CN1 LVDS

RemoveScrew

Remove

Screw

Remove

Screw

LCD DRIVER REMOVALRemove the screws and then the brace.


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DISASSEMBLY

BALLAST REMOVALRemove the shield and then the ballast. Be sure all heat sinks and insulators are in placewhen re-assembling.

Protects the

Outputs

Insulator

Shiny Side

Down

(Conductive)

C t O t

Al ignment

Notch

Heat Transfer MaterialS h i e l d


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DISASSEMBLY

DVD PLAYER REMOVALRemove the tape and then remove the 8 screws holding the DVD Player in place.

Remove

Tape

Remove

Tape


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DISASSEMBLY

Part numbers subject to change. Check GCSC

EXPLODED VIEW

300

121

120

122123

500

510

800

804

801

803

805

802

806

400

900

910

200

822

540

521

821 820

530

531

550


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CIRCUIT DESCRIPTIONS

POWER SUPPLY CONNECTORS

P201 “SMPS” to P800 “Main”

Pin Label Stby Run Diode Check Pin Label Stby Run Diode Check

23 N/C 0V 3.2V OL 24 N/C 0V 0V OL

21 BR1 0V 1.68V OL 22 PWM-DIM 0V 3.38V OL

19 PWR 0V 2.86V OL 20 INV On/Off 0V 3.29V OL

17 ERR 0V 3.3V 1.26V 18 ACD 5.05V 4.57V OL

15 Gnd Gnd Gnd Gnd 16 Gnd Gnd Gnd Gnd


11 5.2V 5.15V 5.15V 0.34V 12 5.2V 5.15V 5.15V 0.34V

9 5.2V 5.15V 5.15V 0.34V 10 5.2V 5.15V 5.15V 0.34V

7 Gnd Gnd Gnd Gnd 8 Gnd Gnd Gnd 0V

5 12V 0V 11.8V 1.69V 6 12V 0V 11.8V 1.69V


1 16.5V 0V 16V 0.31V 2 16.5V 0V 16V 0.31V

BR1 Pin 21 can vary according to OSD Backlight setting. 0.9V 0% to 3.3V 100%


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POWER SUPPLY TEST

The Power Supply must be producing

STAND-BY +5V before performing thistest. With the Power Supply disconnectedfrom other boards and AC applied, confirmthat the Power Supply is producing 5Vfrom either Pins 9, 10, 11 or 12. If not, check the fuse. If the fuse is ok and there is no5V, replace the Power Supply. If 5V is ok, continue.

1st short either pin 9, 10, 11 or 12 (5V) to pin 19 (PWR) using a 10K resistor. The P201connector should be disconnected from the Main board and AC not applied when addingthe jumper. Re-apply power when testing.

Confirm that the other low voltage power supplies are activated.

Pins 1 and 2: 16V

Pins 5 and 6: 12V

Pin 18: AC Detect goes high Fuse F101: Check for 350V (Ballast Voltage)

If any voltage missing, replace the Power Supply. If the 1st test was successful, leave the10K resistor in place.

P2

3 17 511 915 1319 1723 21

4 28 612 1016 1420 1824 22

+5VPWR

10K


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MAIN (DIGITAL) BOARD

MAIN (TOP) REGULATOR CHECKS


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GndGndGndGnd11,18,19,20

n/cn/cn/cn/c14,15

2.66V0VD2.6V_BCMOUT1,2,3,4,5

3.41V0VPower_CTL_2.6VOn/Off Control17

4.98V0.36V+5V_SUBIN6,7,8,10

GndGndGndGndERUNSTBYNAMEFUNCTIONPIN

0V0V3.3VVST_MICONVccCD2.6V/A2.6V_BCM Regulator IC809

0.6V0.6VResetResetBGndGndGndGnd5

RUNSTBYNAMEFUNCTIONPINn/cn/cn/cn/c4

RESET GENERATOR FOR MICRO IC407Q4005V0V+5VOUT3

GndGndGndGndE3.4V0VPower_CTL_3.3VOn/Off Control2

5V0VST_5VPull DownC8.9V0V+9VIN1

3.29V0VRL_ONOn/Off ControlBRUNSTBYNAMEFUNCTIONPIN

RUNSTBYNAMEFUNCTIONPIND3.3V/A3.3V_BCM Regulator IC807

5V SUB SWITCH CONTROLLER fo r Q801Q8023.4V0.1VD3.3V_BCMOUT4

5V0V+5V_SUBOUT5,6,7,8GndGndGndGnd3

0.28V0VQ802On/Off Control2,45V0.36V+5V_SUBIN25V0VST_5VIN1,33.4V0VPower_CTL_3.3VOn/Off Control1

RUNSTBYNAMEFUNCTIONPINRUNSTBYNAMEFUNCTIONPIN

5V SUB SWITCHQ801D3.3V/A3.3V_BCM Regulator turn s on LD800IC806

GndGndGndGnd11,18,19,20

n/cn/cn/cn/c14,15

2.66V0VD2.6V_BCMOUT1,2,3,4,5

3.41V0VPower_CTL_2.6VOn/Off Control17

4.98V0.36V+5V_SUBIN6,7,8,10

GndGndGndGndERUNSTBYNAMEFUNCTIONPIN

0V0V3.3VVST_MICONVccCD2.6V/A2.6V_BCM Regulator IC809

0.6V0.6VResetResetBGndGndGndGnd5

RUNSTBYNAMEFUNCTIONPINn/cn/cn/cn/c4

RESET GENERATOR FOR MICRO IC407Q4005V0V+5VOUT3

GndGndGndGndE3.4V0VPower_CTL_3.3VOn/Off Control2

5V0VST_5VPull DownC8.9V0V+9VIN1

3.29V0VRL_ONOn/Off ControlBRUNSTBYNAMEFUNCTIONPIN

RUNSTBYNAMEFUNCTIONPIND3.3V/A3.3V_BCM Regulator IC807

5V SUB SWITCH CONTROLLER fo r Q801Q8023.4V0.1VD3.3V_BCMOUT4

5V0V+5V_SUBOUT5,6,7,8GndGndGndGnd3

0.28V0VQ802On/Off Control2,45V0.36V+5V_SUBIN25V0VST_5VIN1,33.4V0VPower_CTL_3.3VOn/Off Control1


5V SUB SWITCHQ801D3.3V/A3.3V_BCM Regulator turn s on LD800IC806

MAIN (BOTTOM) REGULATOR CHECKS


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Screen Print for Pin No is incorrect, use IC

GndGndGndGnd11,12,18,

19,20

0V0Vn/cn/c13, 14,15,16

12.36V0VLVDS 12VOUT5,6,7,81.29V0VD1.2V_BCMOUT1,2,3,4,5

6.16V0VQ900On/Off Control2,43.41V0VPower_CTL_1.2VOn/Off Control17

12.36V0V12VIN1,35V0.38V+5V_SUBIN6,7,8,10


LVDS 12V SWITCHQ901D1.2V/A1.2V BCM REGULATORIC805

0V0VGndGndE3.29V0.26V3.3V_TMDS_SWIN3

0V0VLVDS Switch ControlPull Down 12VC1.8V0V'+1.8V_NTPOUT2

0.75V0VLVDS_PANEL_CTRLControlBGndGndGndGnd1


LVDS 12V SWITCH CONTROLLER Q901Q900+1.8V_NTP REGULATORIC801

GndGndGndGnd43.4V0VBCM_RESETOUT6

3.43V3.43V3.3VST_MICONOUT33.4V0VReset from IC400On/Off Control1

5V5VST_5VIN23.41V0VD3.3V_BCMIN14


ST-BY 3.3V DC-DC CONVERTERIC808BCM RESETIC401

Screen Print for Pin No is incorrect, use IC

GndGndGndGnd11,12,18,

19,20

0V0Vn/cn/c13, 14,15,16

12.36V0VLVDS 12VOUT5,6,7,81.29V0VD1.2V_BCMOUT1,2,3,4,5

6.16V0VQ900On/Off Control2,43.41V0VPower_CTL_1.2VOn/Off Control17

12.36V0V12VIN1,35V0.38V+5V_SUBIN6,7,8,10


LVDS 12V SWITCHQ901D1.2V/A1.2V BCM REGULATORIC805

0V0VGndGndE3.29V0.26V3.3V_TMDS_SWIN3

0V0VLVDS Switch ControlPull Down 12VC1.8V0V'+1.8V_NTPOUT2

0.75V0VLVDS_PANEL_CTRLControlBGndGndGndGnd1


LVDS 12V SWITCH CONTROLLER Q901Q900+1.8V_NTP REGULATORIC801

GndGndGndGnd43.4V0VBCM_RESETOUT6

3.43V3.43V3.3VST_MICONOUT33.4V0VReset from IC400On/Off Control1

5V5VST_5VIN23.41V0VD3.3V_BCMIN14


ST-BY 3.3V DC-DC CONVERTERIC808BCM RESETIC401

MAIN BOARD X400 AND X200 CHECK

2 /X400

2 /X400


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TUNER VIDEO AND SIF OUTPUT CHECK

For Easy Access, pop the shield off the tuner. If you leave the shield on you can still accessthe same pins. Be careful not to accidentally ground out you test lead on the shield.

Pin 16 Composite Video

Pin 14 Audio SIF

Pin 3 Tuner B+ (5V)


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MAIN LVDS CHECK

To confirm that the Main board is outputting Picture Content signals, check P902 (LVDS)

for output. Check pins 11-20. This signals vary, but looking for signals like the ones shownbelow on any of these pins will confirm the output of video content. This signal is usinga standard SMTE Color Bar output from a generator as the input source. Rememberthere are actually 10 pins with LVDS signals. This only represents two waveforms as anexample.

P902

Location

Pin 11

MAINPWB


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P800 “Main” to P201 “SMPS” P401 “MAIN” to “Front Keys”Pin Label Stby Run Diode Check Pin Label Stby Run Diode Check

1, 2 16V 0V 16V OL 1 KEY3 3.4V 3.4V 1.4V

3, 4 Gnd Gnd Gnd Gnd 2 KEY4 3.4V 3.4V 1.4V

5, 6 12V 0V 11.8V 3.03V 3 Gnd 0V 0V Gnd

7, 8 Gnd Gnd Gnd Gnd 4 Gnd 0V 0V Gnd

9, 10 ST-5V 5V 5.15V 1.23V 5 KEY-1 3.4V 3.4V 1.4V

11, 12 ST-5V 5V 5.15V 1.23V 6 KEY-2 3.4V 3.4V 1.4V13, 14 Gnd Gnd Gnd Gnd 7 n/c 0V 0V OL

15, 16 Gnd Gnd Gnd Gnd 8 ST-5V 5V 5V 0.53V

17 VBR-B 5V-MNT 0V 3.3V OL 9 PWM-LED 0V 0V 0.8V

18 AC-DET 5V 4.57V OL 10 IR 4.1V 4.1V 2.3V

19 RL-ON 0V 2.86V 1.25V 11 n/c 0V 0V OL

20 INV-On/Off 0V 3.29V 2.15V 12 Gnd 0V 0V Gnd

21 BR1 0V 1.68V OL 13 LED-G 0V 2.1V 0.8V

22 VBR-B 0V 3.38V 2.15V 14 LED-R 2.1V 0V 0.8V

23 n/c 0V 3.2V OL 15 Gnd 0V 0V Gnd

24 n/c 0V 0V OL

MAIN VOLTAGES


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MAIN VOLTAGES

For locations, refer to the Main board’s bottom view. The panel control is on pin 33 of

IC407. Q900 turns on Q901, the LVDS Switch generats LVDS 12V. All voltages are shownon the Interconnect diagram in the schematics section. LVDS Signal Waveforms are shownon the back of Interconnect diagram.

LVDS 12VLVDS 12V


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P900 “Main” to P402 “DVD Player”

Pin Label Stby Run Diode Check

1 Disk-Enable 3.4V 3.4V No Disc

0V Disc In 1.68V

2 DVDP-RXD 0.7V 3.08V 3V

3 DVDP-TXD 0.7V 3.4V 3V

4 Gnd Gnd 0V Gnd

P901 “Main” to CN400 “DVD Player”

Pin Label Stby Run Diode Check

1 12V 0V 12.3V 3V

2 Gnd 0V 0V Gnd

3 DVDP 3.3V 3.4V 3.37V .099V

4 Gnd 0V 0V Gnd5 Gnd 0V 0V Gnd

6 5V 0V 5.01 0.45V


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MCN1

To Backlight

Right Side

To BacklightLeft Side

Transformers

Ballast Start Det

LED LED1

F1

8A/125V

BALLAST ASSEMBLY


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BALLAST TRANSFORMER WAVEFORMSWarning: secondary is over 1.2Kv.

T1/T2 Pin 6

TransformersTransformers

T1/T2 Pin 1

34V p/p 64.89kHz22.2V p/p 220kHz

PrimarySide

MCN1 “Ballast” to P203 “SMPS”

Pin Label Stby Run Diode1 VBL 0V 24.52V OL

2 VBL 0V 24.52V OL

3 VBL 0V 24.52V OL

4 VBL 0V 24.52V OL

5 VBL 0V 24.52V OL

6 Gnd Gnd Gnd Gnd

7 Gnd Gnd Gnd Gnd

8 Gnd Gnd Gnd Gnd

9 Gnd Gnd Gnd Gnd

10 Gnd_1 Gnd Gnd Gnd

11 BVR_A 0V 1.67V OL

12 On/Off 0V 3.45V OL

13 VBR_B 0V 3.40V OL

14 Gnd_2 Gnd Gnd Gnd


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LCD DRIVER (T-CON)If you test the TV with the shield off of the LCD Driver, reinstall the screws for grounding

purposes. Use the Connector P902 on the Main board for Voltages and Signalreadings.

CN2 CN3

US2

To TFT Panel To TFT Panel

12VF1

6.3V/1.5A


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LCD DRIVER VOLTAGES

Use P902 on the Main board for making voltage, resistance, and waveform checks.

CN1 “LCD Drvier” to P902 “Main”


1 LVDS 12V 0V 12.3V OL 2 LVDS 12V 0V 12.3V OL

3 LVDS 12V 0V 12.3V OL 4 LVDS 12V 0V 12.3V OL

5 Gnd 0V 0V Gnd 6 Gnd 0V 0V Gnd



11 LVDS 0V 1.2V 0.98V 12 LVDS 0V 1.1V 0.98V

13 LVDS 0V 1.2V 1.11V 14 LVDS 0V 1.05V 1.06V

15 LVDS 0V 1.1V 1.06V 16 LVDS 0V 1.09V 1.05V

17 LVDS 0V 1.08V 1.11V 18 LVDS 0V 1.13V 1.06V

19 LVDS 0V 1.14V 1.11V 20 LVDS 0V 1.06V 1.06V

21 n/c 0V n/c OL 22 n/c 0V n/c OL

23 n/c 0V n/c Gnd 24 n/c 0V n/c OL

25 Size Sel 0.4V 3.07V 3V 26 Gnd 0V 0V Gnd


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DVD PLAYER

DVD PLAYER VOLTAGES

Resistance should be taken in diode mode with the connectors removed.

*Pin 2: 3.4V with DVD Player and 0V with no DVD Player.

CN401 C t “DVD” t P904 “M i ”


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FRONT BOARD

FRONT VIEW

REAR VIEW

J2 J1

To Main PWBTo Side Keys PWB ZD33.4V Zener

ZD15V Zener

ZD2

4.1V Zener


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3

2

LG

4

0


FRONT BOARD VOLTAGES

Resistance should be taken in diode mode with the connectors removed.

J1 “Front board” to P401 “Main” J2 “Front board” to P101 “Side Key”


1 KEY3 3.4V 3.4V OL 1 Key 1 3.4V 3.4V OL

2 KEY4 3.4V 3.4V OL 2 Gnd 0V 0V Gnd

3 Gnd 0V 0V Gnd 3 Key 2 3.41V 3.41V OL


5 KEY-1 3.4V 3.4V OL 5 Key 3 3.41V 3.41V OL

6 KEY-2 3.4V 3.4V OL 6 Gnd 0V 0V Gnd

7 n/c 0V 0V OL 7 Key 4 3.41V 3.41V OL

8 ST-5V 5V 5V 2.7V 8 Gnd 0V 0V Gnd

9 PWM-LED 0V 0V 2.4V

10 IR 4.1V 4.1V OL

11 n/c 0V 0V OL

12 Gnd 0V 0V Gnd

13 LED-G 0V 2.1V 3.2V

14 LED-R 2.1V 0V 3.2V

15 Gnd 0V 0V Gnd


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INVISIBLE SPEAKER SYSTEM

Bottom View of Woofer Ports

Woofers

Tweeters Tweeters


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DISASSEMBLY

DISASSEMBLY 42LG60

INTRODUCTIONThis section of the manual will discuss Disassembly of the 42LG60 LCD Direct ViewTelevision. Upon completion of this section the Technician will have a better understandingof the disassembly procedures.

BACK COVER REMOVALRemove the 13 screws shown. Pay attention to the

size and type of screw as there are different types.Putting in the improper screw when reassemblingmay cause damage. Handle the TV carefully whilethe 4 stand screws are removed. The stand fitssnuggly, but could fall out and cause injury. Forsafety, put the 4 stand screws back after removing

the back cover.

BOARD LAYOUT


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DISASSEMBLY

MAIN BOARD REMOVALDisconnect P401, P501, P800, P801, and P900. Note: In the bottom right is connectorP200. This is an open connection. Remove the 2 screws securing the Side input decorative

l i i h i h R h 6 i h M i b d i di d b l

POWER SUPPLY (SMPS) REMOVALDisconnect P2, AC In, P402, and P402. Remove the 6 screws indicated below.


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DISASSEMBLY

CONTROL BOARD REMOVALDisconnect P101, P102 P103, and P104. Remove the LVDS cables by pressing in from the

sides to release and then lift them out. Be careful when removing the LVDS Cables, they’refragile. Press the release tabs to avoid damage to board or to the cable itself. Remove the4 screws indicated below.


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DISASSEMBLY

To

Tweeters

Speaker Box

Removed

SPEAKER BOX REMOVALTo remove the Speaker Box, remove the 4 screws show in circles. Then remove the wire

harness. Carefully disconnect both Tweeters. Unplug P500 from the Main board.


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DISASSEMBLY

EXPLODED VIEW

Part numbers subject to change.Ch k GCSC ( i l i ) f

300

200

801

400

901

900540

820

530

580810

120500

121560

510

803

804570

840

520

521

830

805802


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CIRCUIT DESCRIPTIONS 42LG60

INTRODUCTION

LCD Driver (T-CON)

BacklightConnection

Control Board

Backlight

ConnectionLVDS

Cables

With shield removed



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BACKLIGHT LAYOUT

Back View 18 Bulbs

Power Supply with Ballast

To Backlights Over 1.2KV



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INPUT AC 100V ~ 240V (50/60Hz) 3A

OUTPUT

St-by 5.2V (5A)

12V (2A)

16.5V (1.3A)

P401-P402 950V / 135mA

F700 F101

AC IN

P2 - To Main

P402

To Backlight

P401 To Backlight

8A/250V

5A/250V

335V

POWER SUPPLY LAYOUT



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POWER SUPPLY TEST

To test everything but the backlights.

Disconnect the P2 connector from theMain board. With the Power Supplydisconnected from other boards and ACapplied, confirm that the Power Supplyis producing 5V from either pins 9, 10, 11 or 12. If not, check the fuse. If the fuse is okand there’s no 5V, replace the Power Supply. If 5V is ok then continue.

Remove AC power when adding the jumpers shown in the image. Apply power when makingthe test. Short either pins 9, 10, 11 or 12 (5V) to pin 19 (PWR) using a 10K resistor.This turns on the power supply. Confirm that the other low voltage power supplies areactivated. Pins 1 and 2 should be 16V. Pins 5 and 6 should be 12V. Pin 18 (AC Detect)should go high.

BACKLIGHT TEST

If the 1st test was successful, continue.Remove the power, leave the original10K in place, and add a jumper betweenpin pin 19 (PWR) to pin 20 (INV). ApplyAC Power to the board and observe the

P23 17 511 915 1319 1723 21

4 28 612 1016 1420 1824 22

+5VPWR

10K

P2

3 17 511 915 1319 1723 21

4 28 612 1016 1420 1824 22

+5VPWR

10K

INV


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LCD DRIVER (T-CON) LAYOUT



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LCD DRIVER (T-CON) TESTS

Check Fuse F1 for 12V.

Check the regulator US1

for correct voltage.LD1

1.8V

US10V

3.2V

Use LD1 to determine if The

boot up sequence of The T-CON is OK. If all is OK, this

LED will turn bright blue

shortly after power is

applied then go out shortly

after backlights illuminate .

F1

CN1

LCD Driver LED Status

Power Off Power 1st On Power On

Anode 0V Anode 11.6V Anode 11.6V

Cathode 0V Cathode 0V Cathode 9 5V



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MAIN BOARD LAYOUTIf odd video problems are found, use some freeze spray on IC100 and its circuits.

If the video returns to normal, the board needs to be replaced.

P801Power Supply

P800 P900

To Control Board

P401

To Control PanelP501

To Speakers

P200

[Empty]

IC100



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MAIN BOARD UNDERSIDE

IC405

3.29V 3.31V1

SBY RUN IC810

0V 0V1

SBY RUN

BCM Reset

IC100

Video Processor

IC400 0.4V0V

0.4V

3.37V

0V

3.39V

1

2

3

SBY RUN IC805 0.V0V

0V

0.4V

0.1V

3.3V BCM

5V

0V

3.39V

1.2V

1

2

3

4

5

IC8020V 5V1

SBY RUN

IC101



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MAIN BOARD LD803 CHECK

Use LD803 as a visual aid. This lets you know if the +5V is being converted to 3.3V for

the BCM chip IC100. If LD803 is illuminated, +3.3V is ok. Only half of the dual LED isused.

MAIN BOARD TUNER CHECK

For easy access, pop the shield off the tuner. If you leave the shield on you can still accessth i b t b f l t t id t ll d t t t l d th hi ld

MAIN

PWB

LD803



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Pin 16

Video Signal

Pin 14

SIF Signal

17

16

15

14

13

12

11

10

9

8

7

6

5

4

3

2

1

TDVF-H051F

EBL37676801

NC_1

RF-AGC

+B (5V)

VTU

NC_2

GND

SDA

SCL

AS

DIGITAL_IF1

DIGITAL_IF2

IC_AGC

AUDIO_OUT

SIF

IF_AS

VIDEO_OUT

Shield

Not Used

Not Used

Not Used

Not Used

Not Used

Not Used

Not Used

850mVp/p 20nSec rate

1Vp/p 20uSec rate

MAIN BOARD LVDS P900 CHECK

Test the waveforms while using a SMTE color bar signal as the input.



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MAIN BOARD CONNECTORS

P900 “Main” to P104 “Control”

Pin Stby Run Diode Pin Stby Run Diode

1 0V 11.7V OL 2 0V 11.7V OL

3 0V 11.7V OL 4 0V 11.7V OL

5 0V 0V Gnd 6 0V 0V Gnd

7 0V 0V Gnd 8 0V 0V Gnd

SWITCHED

LVDS 12V

P501 “Main” to“Speakers”

Pin Stby Run Check

1 0V 8V 2.58V

2 0V 8V 2.58V

3 0V 8V 2.58V



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P801 “Main” to P2 “SMPS”

Odd Label Stby Run Diode Check Even Label Stby Run Diode Check

1 16V 0V 16V 0.94V 2 16V 0V 16V 0.94V3 Gnd Gnd Gnd 0V 4 Gnd Gnd Gnd 0V

5 12V 0V 11.8V 1.32V 6 12V 0V 11.8V 1.32V

7 Gnd Gnd Gnd 0V 8 Gnd Gnd Gnd 0V

9 5V 5V 5.15V 1.49V 10 5V 5.15V 5.15V 1.49V

11 5V 5V 5.15V 1.49V 12 5V 5.15V 5.15V 1.49V



17 ERR 3.19V 3.3V OL 18 ACD 4V 4.57V 1.85V

19 PWR 0V 2.86V OL 20 INV 0V 3.29V OL

21* ADIM 0.1V 1.68V OL 22 PDIM 0V 3.38V OL

23 SEL 0V 3.2V OL 24 SYNC 0V 0V OL (Not Used)

* ADIM Pin 21 can vary according to OSD Backlight setting. 0.9V 0% to 3.3V 100%

P401 “MAIN” to “Front Keys”

Pin Stby Run Diode Check P800 “Main” to P102 “Control”



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FRONT LED & POWER TOUCH

J1

Front PWB Assembly

To Main

FRONT CONTROL ASSEMBLY



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CONTROL PANEL VOLTAGES

To FrontControl PWB

P100

SIDE CONTROL PANEL



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INVISIBLE SPEAKER SYSTEM LAYOUT

Right

Tweeter

Left

Tweeter

RightSpeaker Box

LeftSpeaker Box

Speaker Box


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64/87


65/87

32LG40 :: WAVEFORMS


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PDP Training - Fall 2008 68 Schematics 68

3

2

LG

4

0

32LG40 LVDS CABLE WAVEFORMS:

Waveforms taken using SMTP Color Bar input.

All readings give the Scale and Time Base related to scope settings.

Top waveform in each image gives a slower rate.

10mV at 5uS per division.

Bottom waveform shows a blow up sample. 10mV at 2uS per division.

32LG40 :: MAIN BOARD :: MAIN


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PDP Training - Fall 2008 69 Schematics

The symbol refers to safety components.

Only replace with LG parts.

3

32LG40 :: MAIN BOARD :: AUDIO


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3

2

L

G

4

0



32LG40 :: MAIN BOARD :: ME


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3

32LG40 :: MAIN BOARD :: BCM/USB




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3

2

L

G

4

0

Side USB

32LG40 :: MAIN BOARD


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3

32LG40 :: MAIN BOARD :: LVDS/DVD


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3

2

L

G

4

0



32LG40 :: MAIN BOARD :: TUNER P




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3

32LG40 :: MAIN BOARD :: JACKPACKS


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3

2

L

G

4

0


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42LG60 :: WAVE


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LVDS CABLE P900 FROM MAIN PWB TO CONTROL

PWB P101 USING SMTP COLOR BAR INPUT

LAST TWO WAVEFORMS ARE FROM THE TUNER

Measurements +/- 5%


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42LG60 :: MAIN BOARD :: DDR M


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42LG60 :: MAIN BOARD :: AUDIO PROC


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42LG60 :: MAIN BOARD :: HDMI


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42

L

G

6

0


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42LG60 :: MAIN BOARD :: INTERFACE


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42

L

G

6

0

42LG60 :: MAIN BOARD :: REGUL


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42LG60 :: MAIN BOARD :: LVDS/TUNER


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G

6

0

42LG60 :: MAIN BOARD :: AUD


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Documents

training lcd lg 42LG60.pdf