Internal Use Only North/Latin America Europe/Africa Asia/Oceania http://aic.lgservice.com http://eic.lgservice.com http://biz.lgservice.com LED LCD TV SERVICE MANUAL CHASSIS : LD21A MODEL : 19LS3500/350S/350T MODEL : 19LS3500/350S/350T-ZA CAUTION BEFORE SERVICING THE CHASSIS, READ THE SAFETY PRECAUTIONS IN THIS MANUAL.
CONTENTS CONTENTS . ............................................................................................. 2 SAFETY PRECAUTIONS ......................................................................... 3 SERVICING PRECAUTIONS ................................................................... 4 SPECIFICATION ....................................................................................... 6 ADJUSTMENT INSTRUCTION ................................................................ 9 DISASSEMBLY ..
SAFETY PRECAUTIONS IMPORTANT SAFETY NOTICE Many electrical and mechanical parts in this chassis have special safety-related characteristics. These parts are identified by in the Schematic Diagram and Exploded View. It is essential that these special safety parts should be replaced with the same components as recommended in this manual to prevent Shock, Fire, or other Hazards. Do not modify the original design without permission of manufacturer.
SERVICING PRECAUTIONS CAUTION: Before servicing receivers covered by this service manual and its supplements and addenda, read and follow the SAFETY PRECAUTIONS on page 3 of this publication. NOTE: If unforeseen circumstances create conflict between the following servicing precautions and any of the safety precautions on page 3 of this publication, always follow the safety precautions. Remember: Safety First. General Servicing Precautions 1.
IC Remove/Replacement Some chassis circuit boards have slotted holes (oblong) through which the IC leads are inserted and then bent flat against the circuit foil. When holes are the slotted type, the following technique should be used to remove and replace the IC. When working with boards using the familiar round hole, use the standard technique as outlined in paragraphs 5 and 6 above. 3. Solder the connections.
SPECIFICATION NOTE : Specifications and others are subject to change without notice for improvement. 1. Application range This specification is applied to the LCD TV used LD21A chassis. 3. Test method 2. Requirement for Test 1) Performance: LGE TV test method followed 2) Demanded other specification - Safety : CE, IEC specification - EMC : CE, IEC Each part is tested as below without special appointment.
No.
5. Video resolutions (2D) 5.1. Component Input (Y, CB/PB, CR/PR) No. Resolution H-freq(kHz) V-freq(Hz) Pixel clock(MHz) Proposed 1 720*576 15.625 50.00 13.5 SDTV ,DVD 576I 2 720*480 15.73 60.00 13.5135 SDTV ,DVD 480I 3 720*480 15.73 59.94 13.50 SDTV ,DVD 480I 4 720*576 31.25 50.00 27.00 SDTV 576P 5 720*480 31.50 60.00 27.027 SDTV 480P 6 720*480 31.47 59.94 27.00 SDTV 480P 7 1280*720 37.50 50.00 74.25 HDTV 720P 8 1280*720 45.00 60.00 74.
5.3. HDMI Input(PC/DTV) No. Resolution H-freq(kHz) V-freq.(Hz) Pixel clock(MHz) Proposed PC(DVI) 1 Remark DDC 640*350 31.468 70.09 2 720*400 31.469 70.08 3 640*480 31.469 59.94 25.17 EGA X 28.32 DOS O 25.17 VESA(VGA) O 4 800*600 37.879 60.31 40.00 VESA(SVGA) O 5 1024*768 48.363 60.00 65.00 VESA(XGA) O 6 1152*864 54.348 60.053 80.00 VESA O 7 1360*768 47.712 60.015 85.50 VESA (WXGA) O 8 1280*1024 63.981 60.020 108.
ADJUSTMENT INSTRUCTION 1. Application Range (4) Click "Connect" tab. If "Can't" is displayed, check connection between computer, jig, and set. This specification sheet is applied to all of the LCD TV with LD21A chassis. (2) (3) 2. Designation (1) The adjustment is according to the order which is designated and which must be followed, according to the plan which can be changed only on agreeing. (2) Power adjustment : Free Voltage. (3) Magnetic Field Condition: Nil.
3.1. ADC Process (1) ADC - Enter Service Mode by pushing "ADJ" key, - Enter Internal ADC mode by pushing "►" key at "7. ADC Calibration". EZ ADJUST 3.3. EDID data ADC Calibration 0. Tool Option1 ADC Comp 480i NG 1. Tool Option2 ADC Comp 1080p NG 2. Tool Option3 ADC RGB NG 3. Tool Option4 4.
3.4 Function Check * Connecting picture of the measuring instrument (On Automatic control) Inside PATTERN is used when W/B is controlled. Connect to auto controller or push Adjustment R/C POWER ON -> Enter the mode of White-Balance, the pattern will come out. - Check display and sound ■ Check Input and Signal items.
* Manual W/B process using adjust Remote control. ▪ After enter Service Mode by pushing "ADJ" key, ▪ E nter White Balance by pushing " ► " key at "8. White Balance". White Balance EZ ADJUST 0. Tool Option1 1. Tool Option2 2. Tool Option3 3. Tool Option4 4. Tool Option5 5. Country Group 6. Area Option 7. ADC Calibration 8. White Balance 9. 10 Point WB 10. Test Pattern 11. EDID D/L 12. Sub B/C 13. Touch Sensitivity Setting ► Color Temp.
6.3. Method & notice (1) Serial number D/L is using of scan equipment. (2) S etting of scan equipment operated by Manufacturing Technology Group. (3) Serial number D/L must be conformed when it is produced in production line, because serial number D/L is mandatory by D-book 4.0. * Manual Download(Model Name and Serial Number) If the TV set is downloaded by OTA or Service man, sometimes model name or serial number is initialized.
7.2 LAN Inspection 7.2.1. Equipment & Condition ▪ Each other connection to LAN Port of IP Hub and Jig 7.2.1. LAN inspection solution ▪ LAN Port connection with PCB ▪ Network setting at MENU Mode of TV ▪ Setting automatic IP ▪ Setting state confirmation -> If automatic setting is finished, you confirm IP and MAC Address. 7.3. LAN PORT INSPECTION(PING TEST) Connect SET -> LAN port == PC -> LAN Port SET PC 7.3.1. Equipment setting (1) Play the LAN Port Test PROGRAM.
DISASSEMBLY 2 1 3 [Caution] Please unlock latches from Bottom Side, for separating Back Cover from CABINET [Method] Firstly, Grab left side of Speaker Vent Hole(①) and then unlock left side latches(②) slowly. Secondly, Grab center(③) of Back Cover and then separate Back Cover slowly. Copyright © LG Electronics. Inc. All rights reserved.
Rear Copyright © LG Electronics. Inc. All rights reserved. Only for training and service purposes - 17 - Side ETHERNET(T2 Only) FULL SCART Component/AV COMMON HDMI1/2(DVI) SIF TMDS DP/DM TP/TN/RP/RN SC1_R/G/B SC1_CVBS_IN FE_ VOUT CVBS, Y/Pb/Pr, L/R TU_CVBS IF +/ - USB1(2.
EXPLODED VIEW IMPORTANT SAFETY NOTICE * Set + Stand A10 300 510 A2 310 A21 120 A31 200 A5 820 LV1 540 521 900 410 910 400 Many electrical and mechanical parts in this chassis have special safety-related characteristics. These parts are identified by in the Schematic Diagram and EXPLODED VIEW. It is essential that these special safety parts should be replaced with the same components as recommended in this manual to prevent X-RADIATION, Shock, Fire, or other Hazards.
Contents of LCD TV Standard Repair Process No. Error symptom (High category) Error symptom (Mid category) Page 1 No video/Normal audio 1 2 No video/No audio 2 3 A.
Contents of LCD TV Standard Repair Process Detail Technical Manual No.
Standard Repair Process Error symptom LCD TV A. Video error Established date No video/ Normal audio Revised date 2012. 01 .14 1/14 First of all, Check whether all of cables between board is inserted properly or not. (Main B/D↔ Power B/D, LVDS Cable,Speaker Cable,IR B/D Cable,,,) ☞A1 No video Normal audio Normal audio Y ☞A4 Check Back Light On with naked eye N Move to No video/No audio Y On Check Power Board 12v,3.5v etc.
Standard Repair Process LCD TV Error symptom A. Video error Established date No video/ No audio Revised date 2012 . 01 .14 2/14 ☞A4 No Video/ No audio Check various voltages of Power Board ( 3.5V,12V,20V or 24V…) Normal voltage? N Y Check and replace MAIN B/D End Replace Power Board and repair parts Copyright © 2012 LG Electronics. Inc. All rights reserved.
Standard Repair Process Error symptom LCD TV ☞ A5 Check RF Signal level Normal Signal? Y A. Video error Established date Picture broken/ Freezing Revised date 2012. 01 .14 3/14 . By using Digital signal level meter . By using Diagnostics menu on OSD ( Menu→ Set up→ Support → Signal Test ) - Signal strength (Normal : over 50%) - Signal Quality (Normal: over 50%) Check whether other equipments have problem or not.
Standard Repair Process Error symptom LCD TV ☞ A5 Check RF Signal level Normal Signal? N A. Video error Established date Tuning fail, Picture broken/ Freezing Revised date 2012. 01 .14 4/14 Check RF signal cable (DVB satellite signal or not) Check whether other equipments have problem or not. (By connecting RF Cable at other equipment) → Set-Top-Box, Different maker TV etc Check satellite setting. - Check LNB frequency.
Standard Repair Process LCD TV Error symptom ☞A7 Check color by input -External Input -COMPONENT -RGB -HDMI/DVI A. Video error Established date Color error Revised date 2012. 01 .
Standard Repair Process LCD TV Error symptom A. Video error Established date Vertical / Horizontal bar, residual image, light spot, external device color error Revised date 2012. 01 .
Standard Repair Process LCD TV Error symptom B. Power error Established date No power Revised date ☞A11 Check Power LED . Stand-By: Red 2012. 01 .14 7/14 ☞A13 DC Power on by pressing Power Key On Remote control Y Power LED On? N Normal N operation? Check Power On ‘”High” OK? Y Replace Power B/D N Y Check Power cord was inserted properly Replace Main B/D ☞A4 Measure voltage of each output of Power B/D N Normal? Y Close Y ※ Check ST-BY 3.
Standard Repair Process LCD TV Error symptom B. Power error Established date Off when on, off while viewing, power auto on/off Revised date 2012. 01 .
Standard Repair Process LCD TV Error symptom C. Audio error Established date No audio/ Normal video Revised date ☞A15 No audio Screen normal Check user menu > Speaker off 2012. 01 .14 9/14 ☞A16 N Off Check audio B+ 24V of Power Board Normal voltage Y Cancel OFF Check Speaker disconnection Y N Replace Power Board and repair parts N Disconnection Replace MAIN Board End Y Replace Speaker Copyright © 2012 LG Electronics. Inc. All rights reserved.
Standard Repair Process LCD TV Error symptom C. Audio error Established date Wrecked audio/ discontinuation/noise Revised date 2012. 01 .
Standard Repair Process Error symptom LCD TV D. Function error Established date Remote control & Local switch checking Revised date 2012. 01 .14 11/14 1. Remote control(R/C) operating error ☞A17 Check R/C itself Operation Normal Y operating? ☞A17 Check & Repair Cable connection Connector solder N Normal operating? Y Check R/C Operating When turn off light in room Check & Replace Baterry of R/C If R/C operate, Explain the customer cause is interference from light in room.
Standard Repair Process LCD TV Check input signal Error symptom Y Signal input? N Established date External device recognition error Revised date Check technical information - Fix information - S/W Version Check and fix external device/cable Copyright © 2012 LG Electronics. Inc. All rights reserved. Only for training and service purposes D. Function error Technical information? N 2012. 01 .
Standard Repair Process LCD TV Identify nose type Error symptom Circuit noise Mechanical noise E. Noise Established date Circuit noise, mechanical noise Revised date Check location of noise 13/14 Replace PSU (with LED driver) OR Replace LED driver Check location of noise ※ Mechanical noise is a natural phenomenon, and apply the 1st level description. When the customer does not agree, apply the process by stage.
Standard Repair Process LCD TV F. Exterior defect Error symptom Zoom part with exterior damage Exterior defect Module damage Replace module Cabinet damage Replace cabinet Remote controller damage Stand dent Copyright © 2012 LG Electronics. Inc. All rights reserved. Only for training and service purposes Established date Revised date 2012. 01 .
Contents of LCD TV Standard Repair Process No. Error symptom (High category) Error symptom (Mid category) Page 1 No video/Normal audio 1 2 No video/No audio 2 3 A.
Contents of LCD TV Standard Repair Process Detail Technical Manual No.
Standard Repair Process Error symptom LCD TV A. Video error Established date No video/ Normal audio Revised date 2012. 01 .14 1/14 First of all, Check whether all of cables between board is inserted properly or not. (Main B/D↔ Power B/D, LVDS Cable,Speaker Cable,IR B/D Cable,,,) ☞A1 No video Normal audio Normal audio Y ☞A4 Check Back Light On with naked eye N Move to No video/No audio Y On Check Power Board 12v,3.5v etc.
Standard Repair Process LCD TV Error symptom A. Video error Established date No video/ No audio Revised date 2012 . 01 .14 2/14 ☞A4 No Video/ No audio Check various voltages of Power Board ( 3.5V,12V,20V or 24V…) Normal voltage? N Y Check and replace MAIN B/D End Replace Power Board and repair parts Copyright © 2012 LG Electronics. Inc. All rights reserved.
Standard Repair Process Error symptom LCD TV ☞ A5 Check RF Signal level Normal Signal? Y A. Video error Established date Picture broken/ Freezing Revised date 2012. 01 .14 3/14 . By using Digital signal level meter . By using Diagnostics menu on OSD ( Menu→ Set up→ Support → Signal Test ) - Signal strength (Normal : over 50%) - Signal Quality (Normal: over 50%) Check whether other equipments have problem or not.
Standard Repair Process Error symptom LCD TV ☞ A5 Check RF Signal level Normal Signal? N A. Video error Established date Tuning fail, Picture broken/ Freezing Revised date 2012. 01 .14 4/14 Check RF signal cable (DVB satellite signal or not) Check whether other equipments have problem or not. (By connecting RF Cable at other equipment) → Set-Top-Box, Different maker TV etc Check satellite setting. - Check LNB frequency.
Standard Repair Process LCD TV Error symptom ☞A7 Check color by input -External Input -COMPONENT -RGB -HDMI/DVI A. Video error Established date Color error Revised date 2012. 01 .
Standard Repair Process LCD TV Error symptom A. Video error Established date Vertical / Horizontal bar, residual image, light spot, external device color error Revised date 2012. 01 .
Standard Repair Process LCD TV Error symptom B. Power error Established date No power Revised date ☞A11 Check Power LED . Stand-By: Red 2012. 01 .14 7/14 ☞A13 DC Power on by pressing Power Key On Remote control Y Power LED On? N Normal N operation? Check Power On ‘”High” OK? Y Replace Power B/D N Y Check Power cord was inserted properly Replace Main B/D ☞A4 Measure voltage of each output of Power B/D N Normal? Y Close Y ※ Check ST-BY 3.
Standard Repair Process LCD TV Error symptom B. Power error Established date Off when on, off while viewing, power auto on/off Revised date 2012. 01 .
Standard Repair Process LCD TV Error symptom C. Audio error Established date No audio/ Normal video Revised date ☞A15 No audio Screen normal Check user menu > Speaker off 2012. 01 .14 9/14 ☞A16 N Off Check audio B+ 24V of Power Board Normal voltage Y Cancel OFF Check Speaker disconnection Y N Replace Power Board and repair parts N Disconnection Replace MAIN Board End Y Replace Speaker Copyright © 2012 LG Electronics. Inc. All rights reserved.
Standard Repair Process LCD TV Error symptom C. Audio error Established date Wrecked audio/ discontinuation/noise Revised date 2012. 01 .
Standard Repair Process Error symptom LCD TV D. Function error Established date Remote control & Local switch checking Revised date 2012. 01 .14 11/14 1. Remote control(R/C) operating error ☞A17 Check R/C itself Operation Normal Y operating? ☞A17 Check & Repair Cable connection Connector solder N Normal operating? Y Check R/C Operating When turn off light in room Check & Replace Baterry of R/C If R/C operate, Explain the customer cause is interference from light in room.
Standard Repair Process LCD TV Check input signal Error symptom Y Signal input? N Established date External device recognition error Revised date Check technical information - Fix information - S/W Version Check and fix external device/cable Copyright © 2012 LG Electronics. Inc. All rights reserved. Only for training and service purposes D. Function error Technical information? N 2012. 01 .
Standard Repair Process LCD TV Identify nose type Error symptom Circuit noise Mechanical noise E. Noise Established date Circuit noise, mechanical noise Revised date Check location of noise 13/14 Replace PSU (with LED driver) OR Replace LED driver Check location of noise ※ Mechanical noise is a natural phenomenon, and apply the 1st level description. When the customer does not agree, apply the process by stage.
Standard Repair Process LCD TV F. Exterior defect Error symptom Zoom part with exterior damage Exterior defect Module damage Replace module Cabinet damage Replace cabinet Remote controller damage Stand dent Copyright © 2012 LG Electronics. Inc. All rights reserved. Only for training and service purposes Established date Revised date 2012. 01 .