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LG 42LG60 Manual

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See also: Owner's Manual , Training Manual
Direct View LCD
42LG60
42LG60
Fall 2008

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Summary of Contents for LG 42LG60

  • Page 1 Direct View LCD 42LG60 42LG60 Fall 2008...
  • Page 2 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 LCD DV 42LG60...

  • Page 3: Overview Of Topics To Be Discussed

    Overview of Topics to be Discussed 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.

  • Page 4: Preliminary Matters (The Fine Print)

    When servicing this product, under no circumstances should the original design be modified or altered without permission from LG Electronics. Unauthorized modifications will not only void the warranty, but may lead to property damage or user injury.

  • Page 5: Esd Notice

    Increase the separation between the equipment and the receiver; Connect the equipment to an outlet on a different circuit than that to which the receiver is connected; or consult the dealer or an experienced radio/TV technician for help. LCD DV 42LG60...

  • Page 6: Contact Information

    LG Web Training lge.webex.com LG CS Academy lgcsacademy.com http://136.166.4.200 LCD-DV: 32LG40, 32LH30, 42LG60, 42LG70, 42LH20, 42LH40, 42LH50, 47LG90 PLASMA: 42PG20, 42PQ20, 42PQ30, 50PG20, 50PS80, 50PS60 Plasma Panel Also available on the Also available on the New Training Materials on...
  • Page 7 1. Check the appearance of the Replacement Panel and Circuit Boards for both physical damage and part number accuracy. 2. Check the model label. Verify model names and board model matches. 3. Check details of defective condition and history. Example: Oscillator failure dead set, etc… LCD DV 42LG60...

  • Page 8: Basic Troubleshooting Steps

    The final step is to correct the problem. Be careful of ESD and make sure to check the DC Supplies for proper levels. Make all necessary adjustments and lastly always perform a Safety AC Leakage Test before returning the product back to the Customer. LCD DV 42LG60...
  • Page 9 42LG60 PRODUCT INFORMATION SECTION 42LG60 PRODUCT INFORMATION SECTION Side View This section of the manual will discuss the specifications of the 42LG60 “Thin” LCD Direct View Display Panel. LCD DV 42LG60...
  • Page 10 • 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 2.0 (JPEG, MP3) • ISFccc LCD DV...
  • Page 11 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. Using a sophisticated algorithm, the LG processes picture quality elements including brightness, contrast, color, sharpness and white balance.

  • Page 12: Remote Control

    Remote Control Remote Control BOTTOM PORTION TOP PORTION LCD DV 42LG60...
  • Page 13 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. If a password is required, enter 0000 LCD DV 42LG60...
  • Page 14 Rear and Side Input Jacks Rear and Side Input Jacks Rear Input Jacks Side Input Jacks Main PWB Orientation LCD DV 42LG60...
  • Page 15 7) Do not unplug until unit has automatically Do not remove AC power or the USB Flash Drive. restarted. Do not turn off Power, during the upgrade 8) When download is completed, you will see process. “COMPLETE”. 9) Your TV will be restarted automatically. LCD DV 42LG60...
  • Page 16 42LG60 Dimensions 42LG60 Dimensions There must be at least 4 inches of Clearance on all sides 40-7/8" 2-3/8" 1038.86mm 60.96mm 7-7/8" 200mm 15-13/16" 8" 402mm 204.4mm 6-5/8" 3-7/8" 168.78mm 100mm Center 31-5/16" Model No. 795mm Serial No. Label 29-3/8" 11-7/8"...
  • Page 17 DISASSEMBLY AND TROUBLESHOOTING SECTION 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. LCD DV 42LG60...
  • Page 18 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. LCD DV 42LG60...

  • Page 19: Circuit Board Layout

    Circuit Board Layout T-CON EAT56803901 (Shield Removed) LVDS Backlight Backlight Cables Power Connection Power Connection LVDS Cables TruMotion Board Ft Control Board Side Side Inputs Board Touch LED POWER SUPPLY Main “Digital” Board (SMPS) Board Invisible Speakers LCD DV 42LG60...

  • Page 20: Backlight Information

    Backlight Information 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~3.1V RMS 58Khz LCD DV 42LG60...
  • Page 21 Introducing EEFL and CCFL Introducing EEFL and CCFL Simple structure, Low price Simple structure Low Cost Complicated structure Lamp manufacturing process Large number of Lamp Lamp assembly structure Drive by single inverter LCD DV 42LG60...
  • Page 22 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 LCD DV 42LG60...
  • Page 23 Shock Hazard F101 8A/250V P402 AC IN AC IN INPUT AC 100V ~ 240V (50/60Hz) 3A F700 5A/250V P401 and P402 St-by 5.2V (5A) TO BACKLIGHT 335V 12V (2A) CONNECTORS 16.5V (1.3A) P401-P402 950V / 135mA MODEL PLHL-T715A LCD DV 42LG60...
  • Page 24 42LG60 POWER SUPPLY 42LG60 POWER SUPPLY TURN ON COMMANDS FROM MAIN PWB TURN ON COMMANDS FROM MAIN PWB BALLAST SECTION POWER SUPPLY (SMPS) In Stand-By Primary Side is 178V 1.2Kv Ballast 160V/380V In Run it is 380V 45Khz Driver FETs...
  • Page 25 42LG60 P801 ON MAIN PWB TO SMPS 42LG60 P801 ON MAIN PWB TO SMPS C813 10uF SMPS PWB MAIN PWB C852 P801 0.1uF C895 0.1uF C851 100uF SBY5V C846 100uF C897 0.1uF 3.3VST Micon IC407 R465 4.7K 5V MNT R458 P4.2/AD2...
  • Page 26 Power Supply Power Supply Backlight Drive Backlight Drive Signal Effects 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. LCD DV 42LG60...
  • Page 27 (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. Check the following: Pins 1 and 2 for +16V Pins 5 and 6 for +12V LCD DV 42LG60...
  • Page 28 If 300V DC is present, observe the L and R center legs on the left hand side of ballast transformer T701. Look for 58Khz pulse at 8.7V p/p. If yes, confirm connectors to backlight OK. If OK, then panel is defective. If no pulse is found, replace the Power Supply. LCD DV 42LG60...
  • Page 29 Power Supply Ballast Board Field Issue 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 LCD DV 42LG60...
  • Page 30 P2 Odd "SMPS" to P801 "Main PWB" Label STBY Diode Check 0.94V 11.8V 1.32V 5.15V 1.49V 5.15V 1.49V 3.19V 3.3V Not Used 2.86V ADIM 0.1V 1.68V 3.2V Not Used Resistance taken in Diode Mode with Connectors Removed LCD DV 42LG60...
  • Page 31 5.15V 5.15V 1.49V 5.15V 5.15V 1.49V 4.57V 1.85V 3.29V PDIM Pin 22 can vary according to OSD Backlight PDIM 3.38V setting. 0.9V 0% to 3.3V 100% SYNC Not Used Resistance taken in Diode Mode with Connectors Removed LCD DV 42LG60...
  • Page 32 Place the Oscilloscope Probe along side the wire from P401 and P402 connectors to the Ballast and a 17.5μ sec sine waveform should be measured this would be an indication that the ballast supply is functioning. Resistance taken in Diode Mode with Connectors Removed LCD DV 42LG60...
  • Page 33 24 frames per second system used for recording, the picture develops visual artifacts when converted to 60 frames per second. 3:2 Pull Down was developed to eliminate this problem. Frame Rate Conversion (Real Cinema) eliminates the need for 3:2 Pull Down. LCD DV 42LG60...
  • Page 34 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). Conventional LCD DV 42LG60...
  • Page 35 24P Real Cinema 24P Real Cinema Frame Rate Conversion eliminates the need for 3:2 Pull Down Conversion LCD DV 42LG60...

  • Page 36: Trumotion Pwb (With Shield)

    TruMotion PWB (With Shield) TruMotion PWB (With Shield) LCD DV 42LG60...
  • Page 37 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. LCD DV 42LG60...
  • Page 38 TruMotion PWB (Layout with Shield Removed) TruMotion PWB (Layout with Shield Removed) X101 IC108 IC109 IC110 LCD DV 42LG60...
  • Page 39 TruMotion PWB Regulators Identified and Voltages IC108 IC109 IC110 5 (1.2V) 5 (0V) 5 (2.5V) 4 (1.3V) 4 (1.79V) 4 (0V) 3 (0V) 3 (0V) 3 (0V) 2 (3.37V) 2 (3.36V) 2 (3.3V) 1 (3.29V) 1 (3.29V) 1 (3.37V) LCD DV 42LG60...
  • Page 40 TruMotion PWB Crystal X101 Check TruMotion PWB Crystal X101 Check 1.7Vp/p 20.25Mhz Only when set is on Control PWB X101 Location LCD DV 42LG60...

  • Page 41: Lcd Controller Board

    ( easily measured at fuse F1). Diode LD1 is a boot up indicator and is helpful in troubleshooting as a quick indication of a loss of supply and or a Boot Up problem. LG Philips LCD Drive IC Next Slide...
  • Page 42 CON (TFT Drive) PWB (Shield Removed) EAT56803901 CON (TFT Drive) PWB (Shield Removed) EAT56803901 To TFT Panel To TFT Panel Remember to replace screws for ground purposes if turning on the set. Control LCD DV 42LG60...
  • Page 43 Check Fuse backlights illuminate if all is OK. F1 for 12V Power Off Power 1 Power On Anode 0V Anode 11.6V Anode 11.6V Cathode 0V Cathode 0V Cathode 9.5V LED OFF LED ON LED OFF LCD DV 42LG60...

  • Page 44: Input Signal Processing

    • USB (Side Input) • AV Composite • SIF and SAP Output Signals • Dual 10 Bit LVDS to the Control Board • Audio output signals to the Speakers • Digital Audio Output Coaxial and Optical • ON OFF Control LCD DV 42LG60...
  • Page 45 Main PWB Layout Main PWB Layout Troubleshooting 42LG60 VIDEO PROCESSOR IC100 RUNS HOT, THIS IS NORMAL. LD803 3.3V-BCM OK LD803 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.
  • Page 46 0.4V 3.39V Processor 0.1V 1.2V IC400 Q902 LVDS 12V Switch LVDS 12V Switch Control Q901 Output 5~8 (12V) IC805 IC802 IC101 IC405 IC810 SBY RUN IC405 IC802 IC810 3.29V 3.31V 0.3V 3.3V 1.8V 0.6V 0.6V 0.3V 3.31V LCD DV 42LG60...
  • Page 47 Main PWB X400 and X200 Check X200 780mVp/p Video Processor Crystal 54Mhz Only when set is on Use left side of Main PWB X400 L206 X200 Location 2.4Vp/p 24Mhz MAIN Main PWB X400 Location Set on or off Microprocessor Crystal LCD DV 42LG60...
  • Page 48 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. Main PWB LD803 Location Note: Only ½ of the dual LED is used. LCD DV 42LG60...
  • Page 49 Pin 3 Tuner B+ (5V) still access the same pins. Be careful not to accidentally ground out your test lead on the shield. (Note: This is a picture from a different model, but the concept is the same) LCD DV 42LG60...
  • Page 50 Main PWB Tuner Video and SIF Output Check 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 1Vp/p 20uSec rate Tuner Location LCD DV 42LG60...
  • Page 51 This signal is using standard SMTE Color Bar output from a generator as the input source. Pin 11 P900 Location MAIN PWB Pin 16 This is just a sample of two pins on the LVDS. There are 24 pins carrying video. LCD DV 42LG60...
  • Page 52 5.15V 1.47V 3.19V 3.3V 2.89V 2.86V 1.1V 0.1V 1.68V 3.2V Pin 17 ERR is not used. Pin 21 ADIM is a fixed voltage. Pin 23 SEL is not used. Resistance taken in Diode Mode with Connectors Removed LCD DV 42LG60...
  • Page 53 5.15V 1.47V AC Det 4.57V 3.29V 1.8V 3.38V SYNC Pin 22 PDIM can vary according to OSD Backlight setting. 0.9V 0% to 3.3V 100% Pin 24 is not used Resistance taken in Diode Mode with Connectors Removed LCD DV 42LG60...
  • Page 54 Diode Check EYEQ-SCL 3.25V 3.25V 2.26V EYEQ-SDA 3.25V 3.25V 2.26V Key1 3.3V 3.3V 1.85V Key2 3.3V 3.3V 1.85V 3.3V 3.3V 3.3V 0.71V 1.47V EYEQ-Reset 3.92V 3.92V 1.35V SPKN SPKP Resistance taken in Diode Mode with Connectors Removed LCD DV 42LG60...
  • Page 55 0.55V 2.58V 2.58V 2.58V 2.58V 3.3V 3.3V 1.39V Use speaker out to test for 3.3V 3.3V 1.28V defective Audio Amp 3.3V 3.3V 1.24V IC501 3.3V 3.3V 1.29V 3.3V 1.35V Resistance taken in Diode Mode with Connectors Removed LCD DV 42LG60...
  • Page 56 Switched LVDS 12V "Control PWB" 11.7V 0.47V 3.3V 1.14V 1.11V 1.12V Video Signal Pins 1.11V 1.16V 1.14V 0.5V 3.15V 2.98V 1.14V 1.12V 1.14V Video Signal Pins 1.07V 1.16V Resistance taken in Diode Mode with Connectors 1.16V Removed LCD DV 42LG60...
  • Page 57 1.05V Video Signal Pins 1.11V 1.07V 1.05V FRC Reset 3.25V 1.28v 3.3V 1.14V 1.09V 1.07V Video Signal Pins 1.13V Resistance taken in 1.07V Diode Mode with Resistance taken in Diode Mode 1.07V Connectors Removed with Connectors Removed LCD DV 42LG60...
  • Page 58 FRONT TOUCH AND LED PWB SECTION FRONT TOUCH AND LED PWB SECTION Front PWB Assembly To Main LCD DV 42LG60...
  • Page 59 Front Touch LED Connector J1 Voltage and Resistance Front Touch LED Connector J1 Voltage and Resistance J1 CONNECTOR “Ft LED Touch" to J2 “Ft Control PWB" STBY 3.3V 3.3V 3.3V 3.3V 3.3V 3.3V 3.3V 3.3V With all Connectors Removed, no ground return. LCD DV 42LG60...
  • Page 60 To Front Touch and IR Sensor are LED PWB located on the front of this PWB Light Diffuser for the Light Diffuser for the Intelligent Sensor Intelligent Sensor To Side Key Control PWB To Main PWB IR Sensor LCD DV 42LG60...
  • Page 61 J1 CONNECTOR "Front Control PWB" to "MAIN PWB" P401 LABEL STBY EYEQ-SCL 3.25V 3.25V EYEQ-SDA 3.25V 3.25V Key1 3.3V 3.3V Key2 3.3V 3.3V 3.3V 3.3V 3.3V EYEQ-Reset 3.92V 3.92V SPKN SPKP With all Connectors Removed, no ground return. LCD DV 42LG60...
  • Page 62 J2 CONNECTOR “Ft Control” to “Ft Touch LED" J1 STBY 3.3V 3.3V 3.3V 3.3V J3 CONNECTOR “Ft Control” to “Side Controls" P100 STBY 3.3V 3.3V 3.3V 3.3V 3.3V 3.3V 3.3V 3.3V With all Connectors Removed, no ground return. LCD DV 42LG60...
  • Page 63 SIDE KEYBOARD (FUNCTION KEYS) SECTION SIDE KEYBOARD (FUNCTION KEYS) SECTION P100 To Front Control PWB LCD DV 42LG60...
  • Page 64 Side Control Connector P100 Voltage and Resistance Side Control Connector P100 Voltage and Resistance P100 CONNECTOR “Side Control” to “Front Control" J3 STBY 3.3V 3.3V 3.3V 3.3V With all Connectors Removed, no ground return. LCD DV 42LG60...

  • Page 65: Invisible Speaker Section

    INVISIBLE SPEAKER SECTION INVISIBLE SPEAKER SECTION Right Left Tweeter Tweeter Right Left Speaker Box Speaker Box LCD DV 42LG60...
  • Page 66 Speaker Box Assembly Removed Speaker Box Assembly Removed Speaker Box Removed Tweeters To Remove Speaker Box, remove the 4 screws show in circles remove wire harness. Carefully disconnect both Tweeters. Unplug P500 from Main PWB. LCD DV 42LG60...

  • Page 67: 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.
  • Page 68 Power Supply PWB Removal Power Supply PWB Removal Disconnect P2, AC In, P402 and P402 Remove the 6 screws indicated below in red. LCD DV 42LG60...

  • Page 69: Main Pwb Removal

    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. LCD DV 42LG60...

  • Page 70: Trumotion Pwb Removal

    TruMotion PWB Removal TruMotion PWB Removal LVDS Cables Press in from sides Disconnect P101, P102 P103 and P104 to release Remove the 4 screws indicated below in red. LCD DV 42LG60...
  • Page 71 CON (TFT Drive) PWB Removal CON (TFT Drive) PWB Removal Disconnect CN1, CN2, CN3 and CN4 Remove the 3 screws indicated below in red. LCD DV 42LG60...
  • Page 72 This Power Point shows a graphical representation of the 11 X 17 This Power Point shows a graphical representation of the 11 X 17 foldout page so clarity is limited. foldout page so clarity is limited. LCD DV 42LG60...
  • Page 73 42LG60 CIRCUIT INTERCONNECT DIAGRAM TFT PANEL LD1 Blue LED TFT Drive PWB Check SET 0FF BOOT OK SET ON LED OFF LED ON LED OFF 1.8V Anode Anode 11.6V Anode 11.6V FRONT SIDE OF MAIN PWB 3.2V BACK SIDE OF MAIN PWB...
  • Page 74 LVDS CABLE P900 FROM MAIN PWB TO CONTROL PWB P101 USING SMTP COLOR BAR INPUT LAST TWO WAVEFORMS ARE FROM THE TUNER Measurements +/- 5%...
  • Page 75 42LG60 Conclusion This concludes the 42LG60 training package presentation.

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