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32LG40 32LG40 Direct View LCD Model : 32LG40 32” CLASS LCD HDTV w/ BUILT-IN DVD PLAYER (31.5" diagonal)
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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 (Digital) Board • T-CON Board • Ballast Board LCD DV 32LG40...
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Overview of Topics to be Discussed Overview of Topics to be Discussed 32LG40 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.
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.
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 32LG40...
USA Website (GCSC) aic.lgservice.com Customer Service Website us.lgservice.com LG CS Academy lgcsacademy.com Published March 2008 by LG Technical Support and Training COMPLIANCE COMPLIANCE The responsible party for this device’s compliance is: LG Electronics Alabama, Inc. 201 James Record Road, Huntsville, AL, 35813.
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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 32LG40...
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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 32LG40...
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32LG40 Product Information 32LG40 Product Information Side View This section of the manual will discuss the specifications of the 32LG40 “Thin” LCD Direct View Display Panel. LCD DV 32LG40...
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• Side-loading Progressive Scan DVD Player • Super Multi-Format • 3x HDMI™ 1.3 • AV Mode (Cinema, Sports, Game) • Clear Voice • SimpLink™ Connectivity • Invisible Speaker System • Expert Mode • PC Input • Swivel Stand (Manual) LCD DV 32LG40...
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32LG40 HDTV Logo Familiarization Explained 32LG40 HDTV Logo Familiarization Explained HD RESOLUTION 720p HD Resolution Pixels: 1366 (H) × 768 (V) High definition television is the highest performance segment of the DTV system used in the US. It’s a wide screen, high-resolution video image, coupled with multi-channel, compact-disc quality sound.
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INVISIBLE SPEAKER SYSTEM LG’s 2008 line of TVs include a unique invisible speaker system, tuned by renowned audio expert, Mr. Mark Levinson. Speakers are embedded in strategic spots behind the front cabinet and use minute vibrations to turn the entire front bezel into the speaker system. The result is a clean, polished look, and enhanced audio by increasing the “sweet spot”...
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ENERGY STAR use as much as 60% less energy to perform these functions, while providing the same performance at the same price as less-efficient models. Less energy means you pay less on your energy bill. Draws less than 1 Watt in stand by. LCD DV 32LG40...
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Remote Control Remote Control BOTTOM PORTION TOP PORTION MUTE LCD DV 32LG40...
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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 32LG40...
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Rear and Side Input Jacks Rear and Side Input Jacks Current Software Release 32LG40-UA-v03.12_080711_Download.epk RGB (PC) Audio Optical Audio Side Input Jacks RGB (PC) HDMI RS232 Service Only HDMI Audio Remote Composite Component Composite Y Pr/Pb Main PWB Orientation LCD DV...
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Software release 7/10/08 Service Bulletin: 0IVL20080332 Current Software Release Side Input Jacks 32LG40-UA-v03.12_080711_Download.epk Symptoms 1) When tuned to CADTV 1-1, TV Set Locks-up (Frozen, will not respond to the remote or Video/Audio). 2) DTV Closed captions Lock-up on Channel 20 in Washington DC (DTVCC Service1 On =>...
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TROUBLESHOOTING SECTION TROUBLESHOOTING SECTION 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. LCD DV 32LG40...
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The Stand does not need to be removed. Remove the 18 screws shown by arrows. 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 32LG40...
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Circuit Board Layout Circuit Board Layout Panel p/n EAJ41825601 T-CON p/n EAT56801301 Ballast p/n EAY56797501 LVDS Cables Side Side Controls Inputs Speaker rattle. Speakers Tighten screws at bottom of cabinet Tighten screws holding woofers LCD DV 32LG40...
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Invisible Speaker System Layout Invisible Speaker System Layout Woofers Tweeters Tweeters Speaker rattle. Tighten screws at bottom of cabinet Tighten screws holding woofers Bottom View of Woofer Ports Stand Removed LCD DV 32LG40...
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PWB Layout PWB Layout P203 P201 To Main To Ballast Error WM-D1 Fixed Volts INV On/Off PWR-DIM POWER-ON On/Off ERROR 5.2V 5.2V 5.2V 5.2V 16.5V 16.5V F101 3.15A/250V 334V Actual F100 5A/250V Hot Ground AC IN AC IN LCD DV 32LG40...
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Power Supply (SMPS) PWB Drawing PWB Drawing P201 P203 To Main To Ballast Error 16.5V 16.5V WM-D1 INV On/Off 5.2V 5.2V 5.2V 5.2V ERROR POWER-ON On/Off PWR-DIM fixedV F101 F100 3.15A/250V 5A/250V 334V Actual AC IN AC IN LCD DV 32LG40...
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Power Supply P201 Control Signals from Main PWB P800 Power Supply P201 Control Signals from Main PWB P800 LCD DV 32LG40...
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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 Power Supply. LCD DV 32LG40...
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If 300V present, check P203 for 24V on Pins 1~5. Check P203 Pin 12 for at least 3V (Inverter On/Off). If yes, confirm connectors to backlight OK, if OK, then panel defective. Ballast will not run if either of the Backlight plugs are removed. LCD DV 32LG40...
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Power Supply PWB Removal Power Supply PWB Removal Disconnect P203, P201 and AC In Remove the 4 screws indicated in the red circles. LCD DV 32LG40...
Power Supply Connector P203 Voltage and Resistance P203 "SMPS" to MCN1 "Ballast PWB" Diode Label STBY Check 24.52V 0.33V 24.52V 0.33V 24.52V 0.33V 24.52V 0.33V 24.52V 0.33V 1.67V INV On-Off 3.45V PWM-DIM 3.40V ERROR Resistance taken in Diode Mode with Connectors Removed LCD DV 32LG40...
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LD800 P904 IC502 Audio Selector HDMI IC806 IC600 A3.3V HDMI Selector Ft Keys IC602 HDMI EDID IC402 Serial Port P401 Interface IC601 HDMI EDID Side Inputs To SPK P500 IC501 Audio Processor and Output 16V Pins 49~52 LCD DV 32LG40...
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NAME STBY +3.3V DDRO_VTT 1.29V 5,6,7 D2.6V_BCM 2.6V +5V_SUB 3.2V On/Off Control DDRO_VTT 1.29V IC803 +9V Regulator IC400 RESET GENERATOR TO IC401 3.3BCM (On Back) FUNCTION NAME STBY FUNCTION NAME STBY +12V D3.3V_BCM 3.4V Reset (Lo-Hi) 3.39V LCD DV 32LG40...
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On/Off Control Power_CTL_3.3V 3.4V Q400 RESET GENERATOR FOR MICRO IC407 FUNCTION NAME STBY Reset Reset 0.6V 0.6V IC809 D2.6V/A2.6V_BCM Regulator 3.3VVST_MICON FUNCTION NAME STBY 6,7,8,10 +5V_SUB 0.36V 4.98V On/Off Control Power_CTL_2.6V 3.41V 1,2,3,4,5 D2.6V_BCM 2.66V 14,15 11,18,19,20 LCD DV 32LG40...
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NAME STBY FUNCTION NAME STBY 6,7,8,10 +5V_SUB 0.38V 12.36V On/Off Control Power_CTL_1.2V 3.41V On/Off Control Q900 6.16V 1,2,3,4,5 D1.2V_BCM 1.29V 5,6,7,8 LVDS 12V 12.36V 13, 14,15,16 11,12,18, 19,20 Screen Print for Pin No is incorrect, use IC LCD DV 32LG40...
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With set on or off TP Use Crystal leg top or bottom 1.49V Main PWB X200 X400 Location 660mVp/p 54Mhz MAIN 1.49V 1.49V Only when set is on Main PWB X200 Location TP Use Crystal Side R232 or R233 LCD DV 32LG40...
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Pin 16 Composite Video Pin 14 Audio SIF Pin 3 Tuner B+ (5V) 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. LCD DV 32LG40...
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Main PWB Tuner Video and SIF Output Check Main PWB Tuner Video and SIF Output Check Using SMTP Color Bar Input Pin 14 “SIF” Signal 850mVp/p Using SMTP Color Bar Input Pin 16 “Video” MAIN Signal 1Vp/p 20uSec rate Tuner Location LCD DV 32LG40...
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This signal is using standard SMTE Color Bar output from a generator as the input source. Remember there are actually 10 pins with LVDS signals. This only represents two Waveforms as an example. Pin 11 P902 Location MAIN Pin 16 LCD DV 32LG40...
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Note: In the top right is a connector P200. This is an open connection. (Software Upgrades) Remove the 2 screws securing the Side input decorative plastic piece on the right. Remove the 4 screws securing the Main PWB indicated below in red. LCD DV 32LG40...
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Back Side View LVDS 12V Panel Control from IC407 Pin 33 Q900 turns on Q901 LVDS Switch generating LVDS 12V All voltages are shown on the Interconnect Diagram LVDS Signal Waveforms Shown on back of Interconnect Diagram LCD DV 32LG40...
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0.98V LVDS 1.2V 1.11V LVDS 1.05V 1.06V LVDS 1.1V 1.06V LVDS 1.09V 1.05V LVDS 1.13V 1.06V LVDS 1.08V 1.11V LVDS 1.14V 1.11V LVDS 1.06V 1.06V Size Sel 0.4V 3.07V Resistance taken in Diode Mode with Connectors Removed LCD DV 32LG40...
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1.60V 3.34V 3.3V DVD-SPDIF 3.38V 1.8V 0.83V 3.34V 3.3V DVD-MUTE DVD-L-In2 2.4V 0.8V 0.8V DVD-R-In2 2.4V 0.6V 0.83V *Pin 2: 3.3V With Disc Player and 0V No Disc Player Resistance taken in Diode Mode with Connectors Removed LCD DV 32LG40...
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*Pin 1: 3.4V with No Disc and 0V with Disc inserted 5.01 0.45V P500 CONNECTOR "Main" to "Speakers" P200 CONNECTOR "Main" Software Download Label Diode Check Label Diode Check 8.14V 2.78V 8.14V 2.78V 8.15V 2.78V 8.15V 2.78V Resistance taken in Diode Mode with Connectors Removed LCD DV 32LG40...
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Ballast PWB Assembly (With Shield) Layout Ballast PWB Assembly (With Shield) Layout p/n EAY56797501 Ballast Start Det LED (LED1) MCN1 8A/125V Transformers To Backlight Left Side To Backlight Right Side LCD DV 32LG40...
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Ballast PWB Assembly Layout Ballast PWB Assembly Layout Ballast Start Det LED LED1 MCN1 8A/125V Transformers To Backlight To Backlight Right Side Left Side LCD DV 32LG40...
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Ballast Transformer Waveforms Ballast Transformer Waveforms 34V p/p 64.89kHz 22.2V p/p 220kHz T1/T2 Pin 1 T1/T2 Pin 6 Primary Warning, Side secondary is over 1.2Kv Transformers LCD DV 32LG40...
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Power Supply P201 Control Signals from Main PWB P800 Power Supply P201 Control Signals from Main PWB P800 LCD DV 32LG40...
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Backlight Drive Signal Effects Signal Effects PWMDIM Waveform manipulates Just for the Burst Explanation, Triangle taken from a Oscillator in different the ballast chassis. drive IC. ADIM also manipulates the Burst Triangle Oscillator But it is not used. LCD DV 32LG40...
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Ballast Removal (Heat Sink and Insulators) Ballast Removal (Heat Sink and Insulators) p/n EAY56797501 Heat Transfer Material Be sure to replace “All” heat sink materials and insulators. Protects the Outputs Alignment Notch Insulator Shiny Side Down (Conductive) Cut Out Insulator Alignment Notch LCD DV 32LG40...
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Ballast Connector MCN1 Voltage and Resistance Ballast Connector MCN1 Voltage and Resistance MCN1 "Ballast" to P203 "SMPS" Label STBY Diode Check 24.52V 24.52V 24.52V 24.52V 24.52V Gnd_1 BVR_A 1.67V On/Off 3.45V VBR_B 3.40V Gnd_2 Resistance taken in Diode Mode with Connectors Removed LCD DV 32LG40...
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CON (TFT DRIVE) With Shield (PWB Removal) CON (TFT DRIVE) With Shield (PWB Removal) Remove One Screw at the to of the Brace then Remove LVDS and three screws. Remove Screw Remove Screw Remove Screw CN1 LVDS To Main LCD DV 32LG40...
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Remember to put the three screws back in for ground purposes. To TFT Panel To TFT Panel 6.3V/1.5A 3) 0.0V CN1 LVDS 2) 1.8V Use the Connector P902 on Main 1) 3.3V PWB for Voltages and Signal To Main Readings LCD DV 32LG40...
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Disconnect CN1 LVDS Cable CAUTION: When removing LVDS Cables, be careful. Press the release Tabs to avoid damage to PWB or to the Cable itself. Press in Press in LVDS Connectors Press in from the sides and lift out. LCD DV 32LG40...
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0.88V LVDS 1.2V 0.88V LVDS 1.05V 0.88V LVDS 1.1V 0.88V LVDS 1.09V 0.88V LVDS 1.08V 0.88V LVDS 1.13V 0.88V LVDS 1.14V 0.88V LVDS 1.06V 0.88V Size Sel 0.4V 3.07V Resistance taken in Diode Mode with Connectors Removed LCD DV 32LG40...
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DVD Connector Information The following section covers the Interconnection Voltages and The following section covers the Interconnection Voltages and Resistance checks between the DVD Player and the Main PWB. Resistance checks between the DVD Player and the Main PWB. LCD DV 32LG40...
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DVD Player Removal (1 of 2) DVD Player Removal (1 of 2) Remove the 8 Screws Holding the DVD Player in place Remove Tape LCD DV 32LG40...
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DVD Player Removal (2 of 2) DVD Player Removal (2 of 2) Disconnect CN400, CN401 and CN402 CN403 Not Used CN402 CN401 This screw hidden by tape in previous photo (Step2). CN400 LCD DV 32LG40...
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DVD Player Removed DVD Player Removed Set will work with DVD Player removed LCD DV 32LG40...
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NOTE: If the DVD Player fails, or if any connector from the DVD Player is open, when selecting the DVD player as the input, it will show “No Signal” error. Resistance taken in Diode Mode with Connectors Removed LCD DV 32LG40...
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Diode Check P12V 12.3V 3.22V GP101 *3.4V *3.4V TXD1 0.7V 3.08V P3.3V 3.4V 3.37V 0.78V RXD1 0.7V 3.4V *Pin 1: 3.4V with No Disc and 0V with Disc inserted 1.2V Resistance taken in Diode Mode with Connectors Removed LCD DV 32LG40...
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Resistance checks between the Front PWB and the Main PWB Resistance checks between the Front PWB and the Main PWB and the Front PWB and the Side Key PWB. and the Front PWB and the Side Key PWB. LCD DV 32LG40...
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Front PWB Assembly Layout Front PWB Assembly Layout 5V Zener 4.1V Zener To Main PWB To Side Keys PWB 3.4V Zener LCD DV 32LG40...
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Front PWB Assembly Rear View Layout Front PWB Assembly Rear View Layout POWER IR Receiver POWER BUTTON LCD DV 32LG40...
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Key 2 KEY-1 3.4V 3.4V 3.41V 3.41V Key 3 KEY-2 3.4V 3.4V 3.41V 3.41V Key 4 ST-5V 2.7V PWM-LED 2.4V 4.1V 4.1V LED-G 2.1V 3.2V LED-R 2.1V 3.2V With all Connectors Removed, Resistance taken in Diode Mode. LCD DV 32LG40...
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Side Control Key P101 Connector Layout, Voltage and Resistance P101 "Side Control" to J2 "Front PWB" Label STBY Diode Check 3.4V 3.4V Key 1 3.41V 3.41V Key 2 3.41V 3.41V Key 3 3.41V 3.41V Key 4 With all Connectors Removed, Resistance taken in Diode Mode. LCD DV 32LG40...
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This section shows the 11X17 foldout that ’ s available in the Paper This section shows the 11X17 foldout that ’ s available in the Paper and Adobe version of the Training Manual. and Adobe version of the Training Manual. LCD DV 32LG40...
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32LG40 INTERCONNECT DIAGRAM P203 "SMPS" to MCN1 "Ballast PWB" P201 Odd "SMPS" to P800 "Main PWB" P201 Even "SMPS" to P800 "Main PWB" Label STBY Diode Check TO TFT MODULE Label STBY Diode Check Label STBY Diode Check 24.52V 0.33V 16.5V...
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32LG40 LVDS P902 WAVEFORMS 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.
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32LG40 32LG40 Direct View LCD This concludes the 32LG40 training session.