LG 42LG70 Series Training Manual Download Page 59

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LCD DV 42LG70

March 2009

MAIN Board

Main Board LD803 Function

Main Board

LD803 Location

LD803

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 GREEN, +3.3V is OK.

Note: Only ½ of the dual LED is used.

Circuit turning on LD803 shown on next slide

Summary of Contents for 42LG70 Series

Page 1: ...evaluate its surroundings Using a sophisticated algorithm the LG processes picture quality elements including brightness contrast color sharpness and white balance The result is a picture optimized for it s surroundings more pleasing to watch and which can also save up to 50 in power consumption 24P REAL CINEMA Hi def movies run at the 24 frames per second speed that they were originally ﬁlmed in ...

Page 2: ...ock Manual Clock On Off Timer Sleep Timer Auto Off When no video is present S I D E A U D I O V I D E O I N P U T S O U T P U T S L R Audio Composite Video In 1 HDMI HDCP In 1 USB 2 0 Music and Photos only 1 JPEG MP3 RF In Antenna Cable 1 L R Audio Component Video In 1 R E A R A U D I O V I D E O I N P U T S O U T P U T S L R Audio Out 1 S Video In 1 HD Component Video In Y Pb Pr L R Audio 2 Digit...

Page 3: ...42LG70 42LG70 Published March 2009 Training Manual LCD DIRECT VIEW ...

Page 4: ... CON Board Circuit Board Operation Troubleshooting of Switch mode Power Supply Section 1 Section 2 Contact Information Preliminary Matters Specifications LCD Overview General Troubleshooting Steps Signal Distribution Disassembly Instructions and Voltages Ft Control Board ...

Page 5: ...ich 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 At the end of this Section the Technician should be able to Identify the Circuit Boards and have the ability and knowledge necessary to safely remove and replace any Circuit Board or Ass...

Page 6: ...Electronics Unauthorized modifications will not only void the warranty but may lead to property damage or user injury If wires screws clips straps nuts or washers used to complete a ground path are removed for service they must be returned to their original positions and properly fastened CAUTION CAUTION To avoid personal injury disconnect the power before servicing this product If electrical powe...

Page 7: ...ce pursuant to Part 15 of the FCC Rules These limits are designed to provide reasonable protection against harmful interference when the equipment is operated in a residential installation This equipment generates uses and can radiate radio frequency energy and if not installed and used in accordance with the instruction manual may cause harmful interference to radio communications However there i...

Page 8: ... 847 7597 USA Website GSFS http gsfs america lge com Customer Service Website us lgservice com LG Web Training lge webex com LG CS Academy lgcsacademy com LG Electronics Alabama Inc 201 James Record Road Huntsville AL 35813 http 136 166 4 200 Published March 2009 by LG Technical Support and Training 32LG40 32LH30 37LH55 42LG60 42LG70 42LH20 42LH40 42LH50 42LH90 42SL80 47LG90 47LH85 42PG20 42PQ20 4...

Page 9: ...l 4 C MOS circuits are sensitive to static electricity Use caution when dealing with these IC and circuits 5 Exercise care when making voltage and waveform checks to prevent costly short circuits from damaging the unit 6 Be cautious of lost screws and other metal objects to prevent a possible short in the circuitry 1 Check the appearance of the Replacement Panel and Circuit Boards for both physica...

Page 10: ...examination using your senses the first check should always be the DC Supply Voltages to those circuits under test Always confirm the supplies are not only the proper level but be sure they are noise free If the supplies are missing check the resistance for possible short circuits Isolate To further isolate the failure check for the proper waveforms with the Oscilloscope to make a final determinat...

Page 11: ...LCD DV 42LG70 9 March 2009 This section of the manual will discuss the specifications of the 42LG70 LCD Direct View Display Panel 42LG70 PRODUCT INFORMATION SECTION 42LG70 PRODUCT INFORMATION SECTION ...

Page 12: ...ions 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 0 JPEG MP3 ISFccc ...

Page 13: ...like 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 The result is a picture optimized for it s surroundings more pleasing to watch and which can also save up to 50 in p...

Page 14: ... swells SIMPLINK Allows for convenient control of other LG SimpLink products using the existing HDMI connection Invisible Speaker System A new invisible speaker system tuned by renowned audio expert Mr Mark Levinson This unique system incorporates speaker actuators around the perimeter of the entire bezel eliminating traditional speaker drivers and associated grills This not only allows for a slee...

Page 15: ...LCD DV 42LG70 13 March 2009 TOP PORTION BOTTOM PORTION Remote Control Familiarization Remote Control Familiarization ...

Page 16: ...aneously 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 It is possible dependant upon the Software Version a Password may be required to enter the Service Menu If a password is required enter 0000 ...

Page 17: ...LCD DV 42LG70 15 March 2009 Side Input Jacks Rear and Side Input Jacks Rear and Side Input Jacks Main Board Orientation Rear Input Jacks ...

Page 18: ...unt Model No Serial No Label 16 1 410mm 22 9 581 66mm 28 9 734mm 4 4 111 8mm 11 6 294 6mm Center 7 9 200mm 5 4 138mm 7 9 200mm 11 2 285mm 1 8 45 6mm Weight without Stand 42 1 lb Weight with Stand 47 8 lb There must be at least 4 inches of Clearance on all sides 16 42LG70 Product Dimensions 42LG70 Product Dimensions ...

Page 19: ...ircuit Board Identification of the 42LG70 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 DISASSEMBLY SECTION DISASSEMBLY SECTION ...

Page 20: ...ck Cover Removing the Back Cover The Stand does not need to be removed Remove the 16 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 ...

Page 21: ...LCD DV 42LG70 19 March 2009 Power Supply Board Removal Power Supply Board Removal Disconnect P201 AC In and P204 Remove the 4 screws indicated by the arrows P201 AC In P 2 0 4 ...

Page 22: ...he two screws holding the Decorative plastic piece on the right side Remove the plastic piece Remove the two pieces of tape on the left side holding down the cables and the one at the top Remove the remaining 11 screws indicated by the arrows TAPE TAPE Decorative Plastic TAPE Under Plastic ...

Page 23: ...his is an open connection Remove the 2 screws securing the Main Board Note The top 2 and bottom 2 screws were removed during the shield removal process P1001 P1000 P800 P404 P501 P200 Upgrades NOTE Look carefully on top and behind the BCM and Micronas IC Look for a piece of Chocolate Heat Transfer Material Be sure to transfer to new Board if replaced ...

Page 24: ...move the 3 Screws in the T CON shield Lift up the left bracket and work the shield out and off CN1 CN5 CN4 CN2 Disconnect CN1 CN2 CN4 and CN5 See next slide for details The three screws shown in the picture below are for the Service Position They would already be removed in the previous step Remove and save the tape over the LVDS Cables ...

Page 25: ...ed Flip the lock up and back from the flex cable Then the flex cable can be easily removed To remove the LVDS cables for CN1 or CN2 Press in on the two tabs and slowly rock the cable out of the connector Shown by the arrows in Fig 3 Fig 3 UNLOCKING CN1 CN2 CN4 and CN5 UNLOCKING CN1 CN2 CN4 and CN5 CN4 or CN5 Locked The locking tab is flipped upward T T CON TFT DRIVE Board Removal Continued CON TFT...

Page 26: ...09 This section of the manual will discuss troubleshooting Upon completion of this section the Technician will have a better understanding of how to diagnosis and resolve problems TROUBLESHOOTING SECTION TROUBLESHOOTING SECTION ...

Page 27: ...in Digital Under Shield LVDS Cables Side Controls Backlight Connection To Right Side T CON Under Shield Backlight Connection To Left Side Ballast Under Shield Side Inputs Ft Control AC Input RF Input Tweeter Woofer Woofer Tweeter Rear Inputs T CON p n EAT56803001 BALLAST p n EAY56798701 ...

Page 28: ...UPPLY SECTION POWER SUPPLY SECTION Hot Ground Shock Hazard To Main F100 6 3A 250V AC IN Not used P201 AC IN F101 3 15A 250V Run 385 7V Stby 155 8V From Hot Gnd P204 To Ballast Power Supply SMPS Board Layout Power Supply SMPS Board Layout ...

Page 29: ... 5 4 TURN ON SEQUENCE 5 5 7 In Stand By Primary side is 90V In Run PWR On Primary side is 370V 3 16V Audio 12V 16V AC Det 7 Reg For Micro LVDS 12V 12V 8 8 At point TV is in Stand By state Energy Star compliant Less than 1 Watt 3 LVDS Panel Control Inv On Off Other Circuits BroadCom Module BCM IC100 A DIM Fixed P DIM Manipulates Backlights Other Circuits 9 9 Cust Menu for Backlight Picture Content ...

Page 30: ...V 3 2V R458 R457 5 8K 5V MNT 39 3 3VST Micon R456 IC407 uP P4 2 AD2 3 3K 4 7K ERROR AC DET PWR STV VBR A VBR B P201 ERR PWR BR1 n c ACD INV PWM DIM n c SMPS J34 IC100 BCM GPI0_28 R112 22 L29 GPI0_27 R2124 22 BCMPWM_ VBR A R487 1K 31 R485 100 30 R488 30K 29 P7 0 HBLANK P5 7 CLK02 P5 6 1 3 4 8 7 6 5 Q804 5V 2 Q803 L812 R873 0 n c n c Fixed Voltage 16V 12V SBY5V 16V 12V Gnd Gnd Gnd Gnd Gnd Gnd Gnd Gn...

Page 31: ...indicates the Stand By 5V voltage is present The Main Board sends two commands to the Power Supply Board one being PWR the other is INV ON These two voltages are used to control the power on turn on sequence First via PWR Pin 19 also known as RL ON activates the 24Volt to the Ballast and the 16 Volt and 12 Volt lines to the Main board The 2nd command is INV ON It passes through the Power Supply to...

Page 32: ...generating ACD AC Detect If the conditions a or b above are not met the SMPS Board is defective and must be replaced There is no need to continue with the test c Unplug P201 or P800 and P204 to the ballast TEST 1 2 Add a 10K resistor between 5V STBY pin 9 10 11 or 12 and Pin 19 PWR Apply AC This will turn on the power supply a Check that the 16V and 12V power supplies are turned on P201 16V pins 1...

Page 33: ...ctivity reconfirm the 24V is being generated and output on P204 connector Pin 1 5 If not unplug P204 and recheck If not SMPS is defective If yes Ballast is loading down the 24V line d Confirm the INV On Off line Pin 12 is going to 3V NOTE Pin 11 and 12 on P204 or Pin 12 and 13 on P201 ADIM PDIM must be above 1V or the backlights will be extremely dim This is controlled by the Customer s OSD settin...

Page 34: ...d Gnd Gnd 4 0 49V 16 2V 0V 16V 2 Diode Check Run STBY Label Pin P201 Even SMPS to P800 Main Board Open 0V 0V SEL 23 Open 1 7V 0V 1 ADIM 21 1 6V 2 8V 0V PWR 19 Open 0V 0V ERR 17 Gnd Gnd Gnd Gnd 15 Gnd Gnd Gnd Gnd 13 1 27V 5 1V 5 1V 5V 11 1 27V 5 1V 5 1V 5V 9 Gnd Gnd Gnd Gnd 7 1 6V 12 3V 0V 12V 5 Gnd Gnd Gnd Gnd 3 0 49V 16 2V 0V 16V 1 Diode Check Run STBY Label Pin P201 Odd SMPS to P800 Main Board 1...

Page 35: ...Gnd Gnd Gnd Gnd 7 Gnd Gnd Gnd Gnd 6 0 72V 24V 0V 24V 5 0 72V 24V 0V 24V 4 0 72V 24V 0V 24V 3 0 72V 24V 0V 24V 2 0 72V 24V 0V 24V 1 Diode Check Run STBY Label Pin P204 MCN1 SMPS to MCN1 BALLAST READING FROM PIN 1 TO PIN 2 for STBY and RUN voltages Open N 2 Open 120Vac L 1 Diode Check Run STBY Label Pin SC100 SMPS to AC IN 1 BR1 ADIM Pin 21 Fixed and not used 2 PWM DIM PDIM Pin 22 can vary according...

Page 36: ...N BACKLIGHT SECTION Ballast To Backlights Over 1 2KV EEFL External Electrode Fluorescent Lamp LOW COST Large number of lamps driven by a single inverter Currently number of lamps Unknown To Backlights Over 1 2KV Backlight Layout Backlight Layout ...

Page 37: ...h 2009 Simple structure Low price Complicated structure Simple structure Lamp manufacturing process Lamp assembly structure Low Cost Large number of Lamp Drive by single inverter EEFL Compared to CCFL EEFL Compared to CCFL ...

Page 38: ... 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 EEFL Contacts Bulb Design EEFL Contacts Bulb Design ...

Page 39: ...LCD DV 42LG70 37 March 2009 Ballast Board Layout Ballast Board Layout FS1 Protects 24V 15A 65V MCN1 To Power Supply To Backlights Left Side To Backlights Right Side T1 T2 T3 T4 BALLAST p n EAY56798701 ...

Page 40: ...arch 2009 Ballast Board Transformer Check Ballast Board Transformer Check TOP T4 T3 T2 T1 Caution Over 1 2kV 1 2 3 4 5 6 7 ANY TRANSFORMER PRIMARY SIDE WAVEFORM CHECK 5V p p 5us p div 1V p div 4 3V p p 5us p div 1V p div ...

Page 41: ...0 P5 7 CLK02 P5 6 R873 0 6 8K IC407 uP 0 R834 13 11 PWR BR1 PWM DIM P204 INV On Off 24V L29 SMPS BOARD MAIN BOARD 3 1 13 11 MCN1 2 4 5 6 7 8 9 10 6 7 8 9 10 12 12 INV On Off 24V 3 1 2 4 5 VBR A Analog Dimming Fixed Voltage VBR B PWM Dimming Manipulates the Backlight Brightness via Customer s OSD Manipulates the Backlight Brightness via the BCM Chip Darker Picture Darker Backlights to facilitate im...

Page 42: ...ply Backlight Drive Signal Effects Power Supply Backlight Drive Signal Effects VBR B PWMDIM manipulates the Burst Triangle Oscillator in the ballast drive IC VBR A BR1 ADIM also manipulates the Burst Triangle Oscillator But it is not used ...

Page 43: ...oise Dampening Pads Ballast Board Layout Back View RF Noise Dampening Pads RF NOISE DAMPENING AND HEAT TRANSFER MATERIAL PADS MAKE SURE TO SAVE THESE IF REPLACING THE BALLAST There is a white box outlined on the Board silk screen indicating where the Chocolate goes ...

Page 44: ...l Pads RF NOISE DAMPENING AND HEAT TRANSFER MATERIAL PADS MAKE SURE TO SAVE THESE IF REPLACING THE BALLAST MAKE SURE THEY ARE PLACED IN THE CORRECT LOCATION BEFORE REINSTALLING THE SHIELD Insulates and Heat Transfer for T1 and T2 Insulates and Heat Transfer for T3 and T4 Insulates and Heat Transfer for Q7 Q8 Q9 and Q10 Q7 Q8 Q9 Q10 T1 T2 T3 T4 BALLAST SHIELD MCN1 ...

Page 45: ...B 13 Open 3 2V 0V On Off 12 Open 1 7V 0V 1 VBR_A 11 Gnd Gnd Gnd Gnd_1 10 Gnd Gnd Gnd Gnd 9 Gnd Gnd Gnd Gnd 8 Gnd Gnd Gnd Gnd 7 Gnd Gnd Gnd Gnd 6 Open 24V 0V VIN 5 Open 24V 0V VIN 4 Open 24V 0V VIN 3 Open 24V 0V VIN 2 Open 24V 0V VIN 1 Diode Check Run STBY Label Pin MCN1 Ballast to P204 SMPS 2 VBR B Pin 13 can vary according to type of signal being processed OSD Backlight setting 0 9V 0 to 3 3V 100...

Page 46: ...m 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 Main 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 T CON IC TL22970D LG Philips LCD Drive IC UC1 U15 U16 F1 Next 2 Sli...

Page 47: ...LCD DV 42LG70 45 March 2009 Two LVDS feeds from Main Board T T CON TFT DRIVE Board with Shield CON TFT DRIVE Board with Shield ...

Page 48: ... Drive Board Shield Removed CON TFT Drive Board Shield Removed U15 U16 LD1 US1 F1 CN5 CN4 CN1 CN2 UC1 To Control To TFT Panel To TFT Panel Remember to replace screws for ground purposes if turning on the set is required T CON p n EAT56803001 ...

Page 49: ...t 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 Off Power 1st On Anode 0V Cathode 0V Anode 11 6V Cathode 0V Power On Anode 11 6V Cathode 9 5V LED OFF LED ON LED OFF Check the Regulator US1 for Correct Voltage Check Fuse F1 for 12V F1 CN1 ...

Page 50: ...des and home theater environment Wired Remote Port 2 Component Inputs Y Pr Pb and Audio L R 3 HDMI Inputs back 1 HDMI Side Input RGB PC USB Side Input software upgrades using flash drive AV Composite SIF and SAP Output Signals Quadruple 12 Bit LVDS to the T CON Board Audio output signals to the Speakers Digital Audio Output Coaxial and Optical ON OFF Controls to the SMPS turning on low voltage gen...

Page 51: ... the need for 3 2 Pull Down Internal Dual 12 bit LVDS input Quadruple 12 bit LVDS output Juddering is a phenomenon which appears on film based programming due to the 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 fo...

Page 52: ...Hz 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 Conventional TruMotion 120Hz ...

Page 53: ...ersion eliminates the need for 3 2 Pull Down Conversion 24P Real Cinema Explained 24P Real Cinema Explained An irregular sequence of Frames in a movie or video image 24P Film 24FPS Conventional 60Hz 5 5 120Hz 1 24 sec 1 60 sec 1 120 sec Scene A Scene B Scene C ...

Page 54: ... video returns to normal Board needs to be replaced 1 16 LD803 3 3V BCM OK when Green P800 P404 P1000 P1001 P501 X400 IC1000 Micronas IC100 Broadcom IC407 uP X200 X1000 USB Tuner To SMPS To Front Board Assembly Both P1000 and P1001 to T COM Board For Software Upgrade via Jig To Speakers Look carefully on top and behind the BCM IC and Micronas IC for Chocolate Heat Transfer material Be sure to tran...

Page 55: ... Reset Q804 Q804 IC805 IC406 IC701 IC408 IC702 IC403 IC602 IC400 IC401 IC1003 IC1004 P800 P1000 P1001 TUNER REAR INPUT JACKS SIDE INPUT JACKS IC1000 P501 53 42LG70 Main Board Back View 42LG70 Main Board Back View Voltages are also given in the Interconnect Diagram 2nd Page ...

Page 56: ...Function Label RUN STBY Q901 Label RUN STBY IC812 Output LVDS 12V 12V 0V Pins 5 8 Output 9V 0V Pins 3 On Off 6V 0V Pins 2 4 Gnd Gnd Gnd Pins 2 Input 12V 0V Pins 1 3 Input 12V 0V Pins 1 LVDS Switch Function 9V Regulator Also source for IC812 Function Label RUN STBY Q900 RUN STBY IC803 Gnd Gnd Gnd E Hi then Lo to Q400 0V 0V Pins 3 Hi Lo to IC407 pin 4 0V 0V C Gnd Gnd Gnd Pins 2 Input from IC405 0 59...

Page 57: ... IC1005 STBY RUN Pin 14 0V 3 3V B for IC 3 3V IC702 STBY RUN Label Pin 3 0V 1 2V Output Pin 1 0V 0V Function EEPROM for RS232 Pin 4 0V 0V Gnd Pin 2 0V 3 4V IC403 STBY RUN Label Pins 1 2 Gnd Gnd Gnd Pin 5 0V 3 3V On Off Power CTL Pin 3 0V 0V Function NV RAM OLD Pins 3 4 Gnd Gnd Gnd Pin 6 0V 1 2V FB Pin 4 0V 1 4V Pins 1 2 3 0V 4 9V Pull Up Pin 5 0V 0 15V SDA Pin 7 0V 1V COMP Pin 5 0V 1 2V Pins 4 Gnd...

Page 58: ...400 X200 and X1000 Check X200 Location X400 Location 2 4Vp p 24Mhz Set on or off X400 Microprocessor Crystal 780mVp p 54Mhz Only when set is on Use bottom of L206 X200 Video Processor BCM Crystal X1000 Location MAIN Board 1Vp p 20 25Mhz X1000 Micronas Crystal Only when set is on ...

Page 59: ...rd LD803 Function Main Board LD803 Location LD803 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 GREEN 3 3V is OK Note Only of the dual LED is used Circuit turning on LD803 shown on next slide ...

Page 60: ...27 0 1uF C828 4 7uF L806 D3 3V_BCM C833 0 1uF C835 4 7uF A3 3V_BCM C834 0 1uF LD803 R815 1K IC809 21 P6 3 Power_CTL 3 3V R466 0 3 3V IC802 2 3 1 37 P5 1 Detects 3 3V for BCM Power Sequence BCM 1 2V 2 6V 3 3V 19 11 12 10 9 SBY5V To SMPS R7028 22 AC DET C848 0 1uF R488 30K 29 P7 0 HBLANK 18 4 57V 58 42LG70 Main Board LD803 Circuit Diagram 42LG70 Main Board LD803 Circuit Diagram ...

Page 61: ...ocation For Easy Access pop the shield off the tuner 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 Note This is a picture from a different model but the concept is the same Pin 14 Audio SIF Pin 16 Composite Video Pin 14 Pin 16 Pin 3 Tuner B 5V Pin 1 ...

Page 62: ...Video and Main Board Tuner Video and SIF SIF Output Check Output Check Tuner Location 1Vp p 20uSec rate Pin 16 Video Signal Pin 14 SIF Signal 850mVp p 20nSec rate USING SMTE COLOR BAR SIGNAL INPUT SDA SCL Lines are only active when changing a channel 5V p p ...

Page 63: ...k P1000 LVDS cable for output Check pins 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 Pin 16 This is just a sample of two pins on the LVDS There are 24 pins on P1000 carrying video 2us 50...

Page 64: ...1 LVDS cable for output Check pins 1 12 and 15 26 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 1 Pin 15 This is just a sample of two pins on the LVDS There are 24 pins on P1001 carrying video 2us 500us 2us ...

Page 65: ...A ADIM Is Fixed and is not used Open 0V 0V n c 23 24 Open 5V 5V AC Det 18 Open 1 4V 0V PWM VBRB 22 Open 1 7V 0V PWM VBRA 21 1 89V 3 2V 0V INV On Off 20 1V 2 8V 0V RL ON 19 2 86V 0V 0V 5V MNT 17 Gnd Gnd Gnd Gnd 13 16 1 48V 5 1V ST 5V ST 5V 9 12 Gnd Gnd Gnd Gnd 7 8 3 1V 12 3V 0V 12V 5 6 Gnd Gnd Gnd Gnd 3 4 Open 16V 0V 16V 1 2 Diode Check Run STBY Label Pin P800 CONNECTOR Main to P201 SMPS Board ...

Page 66: ...0V 0V 23 1 27V 1 14V 0V 21 1 27V 1 14V 0V 19 1 27V 1 13V 0V 17 1 27V 1 14V 0V 15 1 27V 1 14V 0V 13 1 27V 1 14V 0V 11 Open 3 3V 0 47V 9 Gnd 0V 0V 7 Gnd 0V 0V 5 Open 12 2V 0V 3 Open 12 2V 0V 1 Diode Check Run STBY Pi n AFLC EN LVDS SEL n c Gnd Gnd 0V 0V 40 1 2V 1 1V 0V 38 1 2V 1 1V 0V 36 1 2V 1 2V 0V 34 1 2V 1 1V 0V 32 1 2V 1 1V 0V 30 1 2V 1 2V 0V 28 Open 0V 0V 26 Open 0V 0V 24 1 27V 1 2V 0V 22 1 27...

Page 67: ...nd 13 1 27V 1 1V 0V 11 1 27V 1V 0V 9 1 27V 1 1V 0V 7 1 27V 1 2V 0V 5 1 27V 1 1V 0V 3 1 27V 1 1V 0V 1 Diode Check Run SBY Pin 1 27V 1 3V 0V 26 1 27V 1 3V 0V 24 1 27V 1 3V 0V 22 1 27V 1 3V 0V 20 1 27V 1 3V 0V 18 1 27V 1 3V 0V 16 Gnd Gnd Gnd 14 1 27V 1 3V 0V 12 1 27V 1 3V 0V 10 1 27V 1 2V 0V 8 1 27V 1 3V 0V 6 1 27V 1 3V 0V 4 1 27V 1 3V 0V 2 Diode Check Run SBY Pin Pins identified in Bold and Blue are...

Page 68: ...ECTOR MAIN Board to Front Board Assy Gnd Gnd Gnd Gnd 15 3V 0V 0V Board Buzz 14 Open 0V 0V Ready 13 Gnd Gnd Gnd Gnd 12 Open 0V 0V EYEQ Reset 11 1 24V 3 9V 3 9V IR 10 Open 0V 0V Ready 9 1 48V 5V 5V 5V ST 8 0 55V 3 3V 0V 3 3V 7 1 77V 3 3V 3 3V Key2 6 1 77V 3 3V 3 3V Key1 5 Gnd Gnd Gnd Gnd 4 Gnd Gnd Gnd Gnd 3 2 13V 3 3V 3 3V EYEQ SDA 2 2 13V 3 3V 3 3V EYEQ SCL 1 Diode Check Run STBY Label Pin ...

Page 69: ...Check Main Board Connector P501 Voltage and Diode Check Diode Mode values taken with all Connectors Removed 2 58V 8V 0V 4 2 58V 8V 0V 3 2 58V 8V 0V 2 2 58V 8V 0V 1 Diode Check Run SBY Pin P501 CONNECTOR Main to Speakers Use speaker out to test for defective Audio Amp IC501 ...

Page 70: ...BOARD SECTION FRONT IR BOARD SECTION J3 J1 To Main Board To Side Key Control Board The Touch Sensitive Power Switch Intelligent Sensor and IR Sensor are located on the front of this Board Light Diffuser for the Intelligent Sensor IR Sensor ...

Page 71: ...LCD DV 42LG70 69 March 2009 Front Board Assembly Front View Layout Front Board Assembly Front View Layout Light Diffuser for the Intelligent Sensor IR Sensor POWER LED 3 Sensors Sensor Close Up ...

Page 72: ...V 3 3V 1 Run STBY Pin Gnd Gnd Gnd Gnd 15 Open 0V 0V Board Buzz 14 Open 0V 0V Ready 13 Gnd Gnd Gnd Gnd 12 Open 0V 0V EYEQ Reset 11 Open 3 9V 3 9V IR 10 Open 0V 0V Ready 9 1 8V 5V 5V 5V ST 8 Open 3 3V 0V 3 3V 7 Open 3 3V 3 3V Key2 6 Open 3 3V 3 3V Key1 5 Open Gnd Gnd Gnd 4 Open Gnd Gnd Gnd 3 Open 3 3V 3 3V EYEQ SDA 2 Open 3 3V 3 3V EYEQ SCL 1 Diode Check Run STBY Label Pin J1 CONNECTOR Front Keys to...

Page 73: ...rface which adheres to front bezel Invisible Speaker Shown separately Front to left has sticky surface which adheres to front bezel Note there is no diaphragm only voice coil Outlined Circle Speaker Attachment post Cabinet works as a diaphragm 2nd Progression Elimination of the conventional speaker The front bezel is shown below Note the outlined circle is the location for the front sticky pad on ...

Page 74: ...rview Invisible Speaker Shown separately Front to left has sticky surface which adheres to front bezel Note there is no Cone Diaphragm only voice coil Spider Dust Cap with adhesive Voice Coil Inside Magnet Frequency Pass Capacitor Mount Mount Speaker Wires Speaker Terminals Speaker Terminal ...

Page 75: ... Manual and Adobe version of the Training Manual The Adobe version of this Training Manual allows the viewer to The Adobe version of this Training Manual allows the viewer to zoom in and out making reading of the small text easier zoom in and out making reading of the small text easier This Power Point shows a graphical representation of the 11 X 17 This Power Point shows a graphical representatio...

Page 76: ...nd Gnd Gnd Gnd 17 Error 0V 0V 19 Power On 0V 2 8V 21 BR1 0V 1 7V 23 N C 0V 0V P201 Odd SMPS to P800 Main PWB 5 1V 5 1V 0 49V 1 6V 1 27V 1 27V 0V 0V 1 6V 0V P201 Even SMPS to P800 Main PWB Pin Label STBY Run Diode Check 2 16 5V 0V 4 Gnd Gnd Gnd Gnd 6 12V 0V 8 Gnd Gnd Gnd 10 5V 5 1V 5 1V 12 5V 5 1V 5 1V 14 Gnd Gnd Gnd Gnd 16 Gnd Gnd Gnd Gnd 18 ACD 5V 5V 20 INV On Off 0V 3 2V 22 PWM DIM 0V 1 4V 24 N ...

Page 77: ...V 0 16V Pin 8 0V 5V Vcc 5V Pins 1 3 0V 5V Input ST 5V Pin 13 0V 3 4V IC400 STBY RUN Label Pins 2 4 0V 0 3V On Off by Q803 Pin 14 0V 0V Function BCM Reset Generator Drives IC401 Pins 5 8 0V 5V Output 5V Pin 15 5V 5V Pins 1 0V 3 3V Input D3 3V BCM IC404 STBY RUN Pin 16 5V ST 5V Pins 2 Gnd Gnd Gnd Function 3 3VST MICON Regulator IC602 STBY RUN Pins 3 0V 0V Hi then Lo to IC401 Pins 1 Gnd Gnd Gnd Pin 1...

Page 78: ...MS Waveforms taken using SMTP Color Bar input All readings give the Scale 10mV and Time Base related to scope settings Top waveform in each image gives a slower rate 2us per division Outlined area is shown in the bottom waveform at 500ns per division time base ...

Page 79: ...MS Waveforms taken using SMTP Color Bar input All readings give the Scale 10mV and Time Base related to scope settings Top waveform in each image gives a slower rate 2us per division Outlined area is shown in the bottom waveform at 500ns per division time base ...

Page 80: ...LG Electronics Inc All right reserved Only for training and service purposes LGE Internal Use Only C 2008 EXPLODED VIEW 300 200 800 804 805 802 803 801 122 120 121 500 510 806 550 810 520 521 540 530 820 400 901 900 ...

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