Direct View LCD 42LG60 Fall 2008
OUTLINE Section 1 Contact Information, Preliminary Matters, Specifications, LCD Overview, General Troubleshooting Steps, Signal Distribution, Disassembly Instructions and Voltages Section 2 Circuit Board Operation, Troubleshooting of : • Switch mode Power Supply • Main Board • Control Board • T-CON Board • Ft Control Board 2 LCD DV 42LG60
Overview of Topics to be Discussed 42LG60 LCD Direct View Display Section 1 This Section will cover Contact Information and remind the Technician of Important Safety Precautions for the Customers Safety as well as the Technician and the Equipment. Basic Troubleshooting Techniques which can save time and money sometimes can be overlooked. These techniques will also be presented. This Section will get the Technician familiar with the Disassembly, Identification and Layout of the LCD Display Panel.
Preliminary Matters (The Fine Print) IMPORTANT SAFETY NOTICE The information in this training manual is intended for use by persons possessing an adequate background in electrical equipment, electronic devices, and mechanical systems. In any attempt to repair a major Product, personal injury and property damage can result. The manufacturer or seller maintains no liability for the interpretation of this information, nor can it assume any liability in conjunction with its use.
ESD Notice (Electrostatic Discharge Notice) Today’s sophisticated electronics are electrostatic discharge (ESD) sensitive. ESD can weaken or damage the electronics in a manner that renders them inoperative or reduces the time until their next failure. Connect an ESD wrist strap to a ground connection point or unpainted metal in the product. Alternatively, you can touch your finger repeatedly to a ground connection point or unpainted metal in the product.
CONTACT INFORMATION Customer Service (and Part Sales) (800) 243-0000 Technical Support (and Part Sales) (800) 847-7597 USA Website (GCSC) aic.lgservice.com Customer Service Website us.lgservice.com LG Web Training lge.webex.com LG CS Academy lgcsacademy.com http://136.166.4.
Safety and Handling and Checking Points Safety and Handling Regulations 1. Approximately 20 minute pre-run time is required before any adjustments are performed. 2. Refer to the Voltage Sticker on the Switch Mode Power Supply silk screening. (+/- ½ volt). 3. Be cautious of electric shock from the Backlight section, it uses high voltage AC. Check that the Power Supply and Drive Circuits are completely discharged because of residual current stored before Circuit Board removal. 4.
Basic Troubleshooting Steps Define, Localize, Isolate and Correct •Define 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 and check for possible overheated components. Capacitors will sometimes leak dielectric material and give off a distinct odor. Frequency of power supplies will change with the load, or listen for relay closing etc. Observation of the front Power LED may give some clues.
42LG60 PRODUCT INFORMATION SECTION Side View This section of the manual will discuss the specifications of the 42LG60 “Thin” LCD Direct View Display Panel.
Basic Specifications • Full HD 1080p Resolution (1920 x 1080) • 50,000:1 Dynamic Contrast Ratio • TruMotion 120Hz • 4x HDMI™ V.1.3 with Deep Color • Intelligent Sensor • 24p Real Cinema • AV Mode (Cinema, Sports, Game) • Clear Voice • LG SimpLink™ Connectivity • Invisible Speaker System • USB 2.
LOGO Familiarization Full HD 1080p Resolution Displays HDTV programs in full 1920 x 1080p resolution for a more detailed picture. TruMotion 120Hz Advance 120Hz panel provides clear, smooth images, even during fast action scenes creating a stable structure for a crisper picture. Intelligent Sensor Unlike other sensors which can only sense brightness of ambient light, LG’s “Intelligent Sensor” uses 4,096 sensing steps to evaluate its surroundings.
Remote Control BOTTOM PORTION TOP PORTION 12 LCD DV 42LG60
Accessing the Service Menu REMOTE TOP PORTION SIDE KEYS To access the Service Menu. 1) Turn the Set On 2) Simultaneously, Press and “Hold” the Menu Key on the Side Key pad and Press and “Hold” the Menu Key on the Remote approximately 5 seconds. 3) If Customer’s Menu appears, continue to hold until it disappears. 4) The Service Menu appears Note: Dependant upon the Software Version, a Password may be required to enter the Service Menu.
Rear and Side Input Jacks Rear Input Jacks Side Input Jacks Main PWB Orientation 14 LCD DV 42LG60
USB Download Screen (Software Update) 1) Create an LG_DTV folder on the USB Flash Drive Shows the Currently Installed Version 2) Copy new software (xxx.epk) to "LG_DTV" folder. Make sure to have correct software file. 3) With TV turned on, insert USB flash drive. 4) You can see the message “TV Software Upgrade” (See figure to right) 5) Cursor left and highlight "START" Button and push “Enter” button using the remote control. 6) You can see the download progress Bar.
42LG60 Dimensions There must be at least 4 inches of Clearance on all sides 40-7/8" 1038.86mm 7-7/8" 200mm 15-13/16" 402mm 8" 204.4mm 6-5/8" 168.78mm Center 31-5/16" 795mm 29-3/8" 746.76mm 14-11/16" 373.38mm 2-3/8" 60.96mm 11-7/8" 301mm 3-7/8" 100mm Model No. Serial No. Label Remove 4 screws to remove stand for wall mount 1-15/16" 49.2mm Weight without Stand: 45 lb Weight with Stand: 53.1 lb 20-1/2" 520.7mm 16 14-7/8" 376.
DISASSEMBLY AND TROUBLESHOOTING SECTION This section of the manual will discuss disassembly and troubleshooting. Upon completion of this section the Technician will have a better understanding of how to diagnosis and resolve problems.
Removing the Back Cover The Stand does not need to be removed Remove the 13 screws indicated. Pay attention to the size and type of screw as there are many different types. Putting in the improper screw when reassembling may Cause damage.
Circuit Board Layout T-CON EAT56803901 (Shield Removed) LVDS Cables Backlight Power Connection Backlight Power Connection LVDS Cables TruMotion Board Ft Control Board Side Key Board Side Inputs POWER SUPPLY (SMPS) Board Touch LED Main “Digital” Board Invisible Speakers 19 LCD DV 42LG60
Backlight Information Back View 18 Bulbs To Backlights Over 1.2KV Power Supply with Ballast EEFL (External Electrode Fluorescent Lamp) LOW COST Large number of lamps driven by a single inverter 2.8V~3.
Introducing EEFL and CCFL Simple structure, Low price Simple structure Complicated structure Lamp manufacturing process Lamp assembly structure 21 Low Cost Large number of Lamp Drive by single inverter LCD DV 42LG60
Electrode Differences between the EEFL and CCFL Key: Long Life Time • For CCFL, Hg gas is consumed mainly near the internal electrode • For EEFL, longer life time is expected because there is no internal electrode consuming Hg gas 22 LCD DV 42LG60
POWER SUPPLY (SMPS) PWB SECTION P2 To Main P401 Heat Sink is Hot Ground Shock Hazard Ballast Section P402 F700 5A/250V 335V INPUT AC 100V ~ 240V (50/60Hz) 3A OUTPUT P401 and P402 TO BACKLIGHT CONNECTORS AC IN F101 8A/250V AC IN St-by 5.2V (5A) 12V (2A) 16.5V (1.
42LG60 POWER SUPPLY TURN ON COMMANDS FROM MAIN PWB POWER SUPPLY (SMPS) In Stand-By Primary Side is 178V In Run it is 380V BALLAST SECTION Drive Sig Bridge Rectifyer AC Det Circuit 6 Stand By 5V Reg Inverter On 12V/24V Regulators 8 1.2Kv 45Khz 1.2Kv Ballast Driver FETs 160V/380V Regulators AC In 1 6 Inverter On Starts the Ballast Drive Signal Manipulates Backlights Backlights turn On 9 11 P-DIM AC Det At point 4 TV is in Stand-By state. Energy Star compliant.
42LG60 P801 ON MAIN PWB TO SMPS 16V SMPS PWB P2 ERR ACD PWR INV ADIM PDIM SEL SYNC 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 ERROR AC DET PWR STV ADM PDS SEL SYNC C813 10uF P801 16V 16V Gnd Gnd 12V 12V Gnd Gnd 5V 5V 5V 5V Gnd Gnd Gnd Gnd 3.3V 4.57V 2.86V 3.29V 1.68V 3.38V 3.2V 0V 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 PDS (PWM Dimming) Manipulates the Backlight Brightness via Customer’s OSD.
Power Supply Backlight Drive Signal Effects PWMDIM manipulates the Burst Triangle Oscillator in the ballast drive IC. ADIM also manipulates the Burst Triangle Oscillator But it is not used.
Power Supply PWB Test (1ST Test All But Backlights) P2 Connector disconnected from the Main PWB AC: Not applied when adding jumpers. Applied when making test. The Power Supply “MUST” be producing STAND-BY +5V and AC Det. (1) Short either pin 9, 10, 11 or 12 (5V) to Pin 19 (PWR) using a 10K resistor. (2) Apply AC to the PWB. This turns on the power supply except for the Ballast Section.
Power Supply PWB Test (2nd Test All Including Backlights) P2 Connector disconnected from the Main PWB. Apply AC after adding jumpers. If the 1st test was successful, continue. Leave original 10K in place. (2): Test the Backlights, jump Pin 19 (PWR) to Pin 20 (INV) and apply AC Power to the PWB. Observe the Backlights. If normal, the backlights should turn on and off 4 times then go off. If only ½ the backlights light, (Right side or Left Side), confirm connectors are OK.
Power Supply Ballast Board Field Issue Back Side of Power Supply PWB T701 Long leads from T701 are arcing through the insulator to ground Mounting Tabs may be bent T701 29 LCD DV 42LG60
Power Supply Connector P2 Odd Pins Voltage and Resistance P2 Odd "SMPS" to P801 "Main PWB" Not Used Not Used Pin Label STBY Run Diode Check 1 16V 0V 16V 0.94V 3 Gnd Gnd Gnd 0V 5 12V 0V 11.8V 1.32V 7 Gnd Gnd Gnd 0V 9 5V 5V 5.15V 1.49V 11 5V 5V 5.15V 1.49V 13 Gnd Gnd Gnd 0V 15 Gnd Gnd Gnd 0V 17 ERR 3.19V 3.3V OL 19 PWR 0V 2.86V OL 21 ADIM 0.1V 1.68V OL 23 SEL 0V 3.
Power Supply Connector P2 Even Pins Voltage and Resistance P2 Even "SMPS" to P801 "Main PWB" Not Used Pin Label STBY Run Diode Check 2 16V 0V 16V 0.94V 4 Gnd Gnd Gnd 0V 6 12V 0V 11.8V 1.32V 8 Gnd Gnd Gnd 0V 10 5V 5.15V 5.15V 1.49V 12 5V 5.15V 5.15V 1.49V 14 Gnd Gnd Gnd 0V 16 Gnd Gnd Gnd 0V 18 ACD 4V 4.57V 1.85V 20 INV 0V 3.29V OL 22 PDIM 0V 3.38V OL 24 SYNC 0V 0V OL PDIM Pin 22 can vary according to OSD Backlight setting. 0.9V 0% to 3.
SMPS PWB Connector P401 or P402 Voltage and Resistance P401 or P402 Backlights Pin STBY Run Diode Check 1 0V >1Kvac 0V 2 0V >1Kvac 0V Caution: AC over 1Kv. Use extreme caution when reading this voltage. Operating Frequency 54Khz. Pins 1 and 2 are actually shorted together. (Either Plug) Reading between P401 and P402 actually reads the Transformer T701 windings. (0.
TRUMOTION PWB SECTION The Control PWB contains the MICRONAS chip IC101. This IC is a Full-HD Rate Converter with Motion Blur Removal and Film DeJuddering for 1080p 100/120 Hz LCD panels. •Vector Based Motion Compensation with Frame Rate Conversion (eliminates the need for 3:2 Pull Down) •Dual 10 bit LVDS input •Quadruple 12 bit LVDS output Motion Blur Removal increases the video frames by Interpolating a new image frame between each original frame (Motion Estimated Data Insertion) MEDI.
TruMotion 120Hz ( Vector Based Motion Compensation) TruMotion 120 Hz can reduce blurring on fast moving scenes. TruMotion carefully analyses the picture signal by using advanced algorithms to automatically calculate a new image frame between each original frame (MEDI).
24P Real Cinema Frame Rate Conversion eliminates the need for 3:2 Pull Down Conversion 35 LCD DV 42LG60
TruMotion PWB (With Shield) 36 LCD DV 42LG60
TruMotion PWB Removing the LVDS Cable Disconnect P101, P103 and P104 LVDS Cables CAUTION: When removing LVDS Cables, be careful. Press the release Tabs to avoid damage to PWB or to the Cable itself. LVDS Connectors Press in from the sides and lift out.
TruMotion PWB (Layout with Shield Removed) X101 IC108 IC109 IC110 38 LCD DV 42LG60
TruMotion PWB Regulators Identified and Voltages (1) (1) (1) IC108 IC109 IC110 5 (1.2V) 4 (1.3V) 3 (0V) 2 (3.37V) 1 (3.29V) 5 (0V) 4 (1.79V) 3 (0V) 2 (3.36V) 1 (3.29V) 5 (2.5V) 4 (0V) 3 (0V) 2 (3.3V) 1 (3.
TruMotion PWB Crystal X101 Check 1.7Vp/p 20.
T-CON (TFT DRIVE) PWB SECTION LCD Controller Board The T Con IC UC1 receives from the Control Board at CN1 and CN2 Quadruple 12 Bit LVDS Signals which it processes into TFT Drive Signals which through connectors CN4 and CN5 control the LCD Panel. IC’s U15 and U16 are “Dynamic Ram IC’s which are High Speed Storage Devices used to store the data until it is time to be addressed. 12V is supplied to the T Con Board on connector CN1 from the Control Board ( easily measured at fuse F1).
T-CON (TFT Drive) PWB (Shield Removed) p/n EAT56803901 To TFT Panel To TFT Panel CN5 CN4 US1 UC1 U15 U16 Remember to replace screws for ground purposes if turning on the set.
T-CON (TFT DRIVE) PWB CHECKS Check the Regulator US1 for Correct Voltage 0V US1 1.8V 3.2V T-CON PWB LD1 F1 CN1 Check Fuse F1 for 12V Power Off Anode 0V Cathode 0V LED OFF 43 Use LD1 to determine if The boot up sequence of The T-CON is OK. This LED will turn bright Blue Shortly after power is applied then go out shortly after backlights illuminate if all is OK. Power 1st On Anode 11.6V Cathode 0V LED ON Power On Anode 11.6V Cathode 9.
MAIN PWB SECTION Input Signal Processing The Broadcom or BCM IC100 is the main signal processing IC.
Main PWB Layout Troubleshooting 42LG60 VIDEO PROCESSOR IC100 RUNS HOT, THIS IS NORMAL. LD803 3.3V-BCM OK LD803 1 16 If odd Video problems are found, use some freeze spray about IC100 and its circuits, If video returns to normal, PWB needs to be replaced.
Main PWB (Back View) Regulator Layout IC400 1 2 3 SBY 0.4V 0V 0.4V RUN 3.37V 0V 3.39V IC805 BCM Reset IC100 Video Processor 1 2 3 4 5 SBY 0.V 0V 0V 0.4V 0.1V RUN 3.3V 5V 0V 3.39V 1.2V 3.3V BCM IC400 LVDS 12V Switch Output 5~8 (12V) Q902 Q901 LVDS 12V Switch Control IC805 IC802 IC101 IC405 IC810 IC405 1 2 3 SBY 3.29V 0V 0.6V RUN 3.31V 0V 0.6V IC802 1 2 3 SBY RUN 0V 5V 0.3V 3.3V 0V 0V 46 IC810 1 2 3 SBY 0V 0V 0.3V LCD DV RUN 0V 1.8V 3.
Main PWB X400 and X200 Check Video Processor Crystal X200 780mVp/p 54Mhz Only when set is on Main PWB X200 Location Use left side of L206 X400 2.
Main PWB LD803 Check LD803 MAIN PWB Main PWB LD803 Location 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. Note: Only ½ of the dual LED is used.
Main PWB Tuner Video and SIF Output Check Pin Location For Easy Access, pop the shield off the tuner Pin 14 Pin 16 Pin 16 Composite Video Pin 14 Audio SIF Pin 1 If you leave the shield on you can still access the same pins. Be careful not to accidentally ground out your test lead on the shield.
Main PWB Tuner Video and SIF Output Check USING SMTE COLOR BAR SIGNAL INPUT Pin 14 “SIF” Signal 850mVp/p 20nSec rate Pin 16 “Video” Signal MAIN PWB 1Vp/p 20uSec rate Tuner Location 50 LCD DV 42LG60
Main PWB LVDS P900 Output Check To confirm that the Main PWB is outputting Picture Content signals, check P900 (LVDS) cable for output. Check 11-22 and 27-38. This signals vary from each other, but looking for signals like the ones shown below on any of these pins will confirm the output of video content. This signal is using standard SMTE Color Bar output from a generator as the input source. Pin 11 P900 Location MAIN PWB This is just a sample of two pins on the LVDS. There are 24 pins carrying video.
Main PWB Connector P801 Odd Pins Voltage and Resistance P801 CONNECTOR "Main" Odd Pins to P2 "SMPS PWB" Pin Label STBY Run Diode Check 1 16V 0V 16V OL 3 Gnd Gnd Gnd Gnd 5 12V 0V 11.8V 3V 7 Gnd Gnd Gnd Gnd 9 5V 5V 5.15V 1.47V 11 5V 5V 5.15V 1.47V 13 Gnd Gnd Gnd Gnd 15 Gnd Gnd Gnd Gnd 17 ERR 3.19V 3.3V 2.89V 19 PWR 0V 2.86V 1.1V 21 ADM 0.1V 1.68V OL 23 SEL 0V 3.2V OL Resistance taken in Diode Mode with Connectors Removed Pin 17 ERR is not used.
Main PWB Connector P801 Even Pins Voltage and Resistance P801 CONNECTOR "Main" Even Pins to P2 "SMPS PWB" Pin Label STBY Run Diode Check 2 16V 0V 16V OL 4 Gnd Gnd Gnd Gnd 6 12V 0V 11.8V 3V 8 Gnd Gnd Gnd Gnd 10 5V 5.15V 5.15V 1.47V 12 5V 5.15V 5.15V 1.47V 14 Gnd Gnd Gnd Gnd 16 Gnd Gnd Gnd Gnd 18 AC Det 4V 4.57V OL 20 STV 0V 3.29V 1.8V 22 PDS 0V 3.38V OL 24 SYNC 0V 0V OL Pin 22 PDIM can vary according to OSD Backlight setting. 0.9V 0% to 3.
Main PWB Connector P401 Voltage and Resistance P401 CONNECTOR "MAIN PWB" to "Front PWB Assy" Pin LABEL STBY Run Diode Check 1 EYEQ-SCL 3.25V 3.25V 2.26V 2 EYEQ-SDA 3.25V 3.25V 2.26V 3 Gnd 0V 0V Gnd 4 Gnd 0V 0V Gnd 5 Key1 3.3V 3.3V 1.85V 6 Key2 3.3V 3.3V 1.85V 7 3.3V 3.3V 3.3V 0.71V 8 5V 5V 5V 1.47V 9 EYEQ-Reset 0V 0V Gnd 10 IR 3.92V 3.92V 1.
Main PWB Connector P800 and P501 Voltage and Resistance P800 CONNECTOR "Main" Odd Pins to P102 "Control PWB" Pin SBY Run Diode Check 1 0V 5V 0.8V 2 0V 5V 0.8V P501 CONNECTOR "Main" to "Speakers" 3 0V 0V Gnd Pin SBY Run Diode Check 4 0.5V 3.3V 0.55V 1 0V 8V 2.58V 5 0V 0V Gnd 2 0V 8V 2.58V 6 0V 16V OL 3 0V 8V 2.58V 7 0V 16V OL 4 0V 8V 2.58V 8 0V 0V Gnd 9 3.3V 3.3V 1.39V 10 3.3V 3.3V 1.28V 11 3.3V 3.3V 1.24V 12 3.3V 3.3V 1.29V 13 3.
Main PWB Connector P900 “Odd Pins” Voltage and Resistance Switched LVDS 12V SCL Video Signal Pins n/c Video Signal Pins n/c Pin SBY Run Diode Check 1 0V 11.7V OL 3 0V 11.7V OL 5 0V 0V Gnd 7 0V 0V Gnd 9 0.47V 3.3V 1V 11 0V 1.14V 1V 13 0V 1.11V 1V 15 0V 1.12V 1V 17 0V 1.11V 1V 19 0V 1.16V 1V 21 0V 1.14V 1V 23 0V 0V OL 25 0.5V 3.15V 2.98V 27 0V 1.14V 1V 29 0V 1.12V 1V 31 0V 1.14V 1V 33 0V 1.07V 1V 35 0V 1.16V 1V 37 0V 1.
Main PWB Connector P900 “Even Pins” Voltage and Resistance Switched LVDS 12V SDA Video Signal Pins FRC Reset Video Signal Pins Resistance taken in Diode Mode with Connectors Removed Pin SBY Run Diode Check 2 0V 11.7V OL 4 0V 11.7V OL 6 0V 0V Gnd 8 0V 0V Gnd 10 0V 3.3V 1V 12 0V 1.14V 1V 14 0V 1.11V 1V 16 0V 1.05V 1V 18 0V 1.11V 1V 20 0V 1.07V 1V 22 0V 1.05V 1V 24 0V 3.25V 1.28v 26 0V 3.3V 3V 28 0V 1.14V 1V 30 0V 1.09V 1V 32 0V 1.
FRONT TOUCH AND LED PWB SECTION J1 Front PWB Assembly To Main 58 LCD DV 42LG60
Front Touch LED Connector J1 Voltage and Resistance J1 CONNECTOR “Ft LED Touch" to J2 “Ft Control PWB" Pin STBY Run 1 3.3V 3.3V 2 3.3V 3.3V 3 5V 5V 4 0V 0V 5 0V 0V 6 0V 0V 7 3.3V 3.3V 8 0V 0V 9 3.3V 3.3V With all Connectors Removed, no ground return.
Front PWB Assembly Layout Right Tweeter The Intelligent Sensor and IR Sensor are located on the front of this PWB J2 To Front Touch LED PWB J1 To Main PWB Light Diffuser for the Intelligent Sensor To Side Key Control PWB J3 IR Sensor 60 LCD DV 42LG60
Front Control Connector J1 Voltage and Resistance J1 CONNECTOR "Front Control PWB" to "MAIN PWB" P401 Pin LABEL STBY Run 1 EYEQ-SCL 3.25V 3.25V 2 EYEQ-SDA 3.25V 3.25V 3 Gnd 0V 0V 4 Gnd 0V 0V 5 Key1 3.3V 3.3V 6 Key2 3.3V 3.3V 7 3.3V 3.3V 3.3V 8 5V 5V 5V 9 EYEQ-Reset 0V 0V 10 IR 3.92V 3.92V 11 SPKN 0V 0V 12 Gnd 0V 0V 13 SPKP 0V 0V 14 n/c 0V 0V 15 Gnd 0V 0V 61 With all Connectors Removed, no ground return.
Front Control Connector J2 Voltage and Resistance J2 CONNECTOR “Ft Control” to “Ft Touch LED" J1 Pin STBY Run 1 3.3V 3.3V 2 3.3V 3.3V 3 5V 5V 4 0V 0V 5 0V 0V 6 0V 0V 7 3.3V 3.3V 8 0V 0V 9 3.3V 3.3V J3 CONNECTOR “Ft Control” to “Side Controls" P100 Pin STBY Run 1 3.3V 3.3V 2 0V 0V 3 3.3V 3.3V 4 0V 0V With all Connectors Removed, no ground return.
SIDE KEYBOARD (FUNCTION KEYS) SECTION P100 To Front Control PWB 63 LCD DV 42LG60
Side Control Connector P100 Voltage and Resistance P100 CONNECTOR “Side Control” to “Front Control" J3 Pin STBY Run 1 3.3V 3.3V 2 0V 0V 3 3.3V 3.3V 4 0V 0V With all Connectors Removed, no ground return.
INVISIBLE SPEAKER SECTION Right Tweeter Left Tweeter Right Speaker Box Left Speaker Box 65 LCD DV 42LG60
Speaker Box Assembly Removed Speaker Box Removed To Tweeters To Remove Speaker Box, remove the 4 screws show in circles remove wire harness. Carefully disconnect both Tweeters. Unplug P500 from Main PWB.
DISASSEMBLY SECTION This section of the manual will discuss Disassembly, Layout and Circuit Board Identification, of the 42LG60 LCD Direct View Television. Upon completion of this section the Technician will have a better understanding of the disassembly procedures, the layout of the printed circuit boards and be able to identify each board.
Power Supply PWB Removal Disconnect P2, AC In, P402 and P402 Remove the 6 screws indicated below in red.
MAIN PWB Removal Disconnect P401, P501, P800, P801 and P900 Note: In the bottom right is a connector P200. This is an open connection. Remove the 2 screws securing the Side input decorative plastic piece on the right. Remove the 6 screws securing the Main PWB indicated below in red. The Main PWB can also be lifted off the mounting frame by; Disconnect P401 and P501. Remove the 1 screw securing the top mounting frame. Swing the PWB away.
TruMotion PWB Removal LVDS Cables Press in from sides to release Disconnect P101, P102 P103 and P104 Remove the 4 screws indicated below in red.
T-CON (TFT Drive) PWB Removal Disconnect CN1, CN2, CN3 and CN4 Remove the 3 screws indicated below in red.
11 X 17 FOLDOUT SECTION This section shows the 11X17 foldout that’s available in the Paper and Adobe version of the Training Manual. The Adobe version of this Training Manual allows the viewer to zoom in and out making reading of the small text easier. This Power Point shows a graphical representation of the 11 X 17 foldout page so clarity is limited.
42LG60 CIRCUIT INTERCONNECT DIAGRAM TFT PANEL LD1 Blue LED TFT Drive PWB Check SET 0FF LED OFF Anode 0V Cathode0V BOOT OK LED ON Anode 11.6V Cathode 0V US1 SET ON LED OFF Anode 11.6V Cathode 9.5V 0V 3.2V CN5 U15 The appearance of LD1 when the set is on appears to be lit dimly. However there is a small hole in the back panel frame and the T-CON PWB that allows the backlight to make it appear lit. 1.
LVDS CABLE P900 FROM MAIN PWB TO CONTROL PWB P101 USING SMTP COLOR BAR INPUT LAST TWO WAVEFORMS ARE FROM THE TUNER Measurements +/- 5%
42LG60 Conclusion This concludes the 42LG60 training package presentation.
