Page 2 - CONTENTS
- 2 - LGE Internal Use Only Copyright © LG Electronics. Inc. All rights reserved. Only for training and service purposes CONTENTS CONTENTS .............................................................................................. 2 SAFETY PRECAUTIONS ................................................
Page 3 - General Guidance; isolation Transformer should always be used; Before returning the receiver to the customer,; AC leakage current check; Leakage Current Cold Check(Antenna Cold Check); Do not use a line Isolation Transformer during this check.; Leakage Current Hot Check circuit; IMPORTANT SAFETY NOTICE; SAFETY PRECAUTIONS
- 3 - LGE Internal Use Only Copyright © LG Electronics. Inc. All rights reserved. Only for training and service purposes 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 e...
Page 4 - SERVICING PRECAUTIONS; CAUTION
- 4 - LGE Internal Use Only Copyright © LG Electronics. Inc. All rights reserved. Only for training and service purposes 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 ...
Page 5 - IC Remove/Replacement; Removal; Circuit Board Foil Repair; At IC Connections
- 5 - LGE Internal Use Only Copyright © LG Electronics. Inc. All rights reserved. Only for training and service purposes IC Remove/Replacement Some chassis circuit boards have slotted holes (oblong) through which the IC leads are inserted and then bent flat against the cir- cuit foil. When holes are...
Page 6 - SPECIFICATION; Requirement for Test; Supported satellite : 22 satellites
- 6 - LGE Internal Use Only Copyright © LG Electronics. Inc. All rights reserved. Only for training and service purposes 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 ch...
Page 9 - DTV
- 9 - LGE Internal Use Only Copyright © LG Electronics. Inc. All rights reserved. Only for training and service purposes 5.3. HDMI Input(PC/DTV) No. Resolution H-freq(kHz) V-freq.(Hz) Pixel clock(MHz) Proposed Remark PC(DVI) DDC 1 640*350 31.468 70.09 25.17 EGA X 2 720*400 31.469 70.08 28.32 DOS O 3...
Page 10 - ADJUSTMENT INSTRUCTION; Main PCB check process
- 10 - LGE Internal Use Only Copyright © LG Electronics. Inc. All rights reserved. Only for training and service purposes ADJUSTMENT INSTRUCTION 1. Application Range This specification sheet is applied to all of the LCD TV with LD21A chassis. 2. Designation (1) The adjustment is according to the ord...
Page 12 - Total Assembly line process
- 12 - LGE Internal Use Only Copyright © LG Electronics. Inc. All rights reserved. Only for training and service purposes 3.4 Function Check - Check display and sound ■ Check Input and Signal items. 1) TV 2) AV (SCART / CVBS) 3) COMPONENT (480i) 4) RGB (PC : 1024 x 768 @ 60hz) (* RGB input : LD21B o...
Page 15 - SET
- 15 - LGE Internal Use Only Copyright © LG Electronics. Inc. All rights reserved. Only for training and service purposes 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 ...
Page 16 - ea; FF; LG; BLOCK DIAGRAM
- 16 - LGE Internal Use Only Copyright © LG Electronics. Inc. All rights reserved. Only for training and service purposes C om po ne nt /A V COMM O N HDMI1/ 2( D V I) IF + /- TU _C V BS SI F U S B1 (2 .0 ) D P/ D M X -t al 24 M X 20 1 CVBS, Y/ P b/Pr, L/ R R ea r TM D S S id e FU LL S C AR T SC 1_ C...
Page 17 - EXPLODED VIEW
- 17 - LGE Internal Use Only Copyright © LG Electronics. Inc. All rights reserved. Only for training and service purposes A2 A21 A5 A31 A10 900 200 400 540 521 810 910 120 300 510 310 * Set + Stand LV 1 EXPLODED VIEW Many electrical and mechanical parts in this chassis have special safety-related ch...
Page 18 - L E D D r i v e r C i r c u i t f o r T N M o d u l e D M B I C; F o r w a r d v o l t a g e s p e c .
THERMAL T H E S Y M B O L M A R K O F T H I S S C H E M E T I C D I A G R A M I N C O R P O R A T E SS P E C I A L F E A T U R E S I M P O R T A N T F O R P R O T E C T I O N F R O M X - R A D I A T I O N .F I L R E A N D E L E C T R I C A L S H O C K H A Z A R D S , W H E N S E R V I C I N G I F I ...
Page 20 - Serial Flash for SPI boot
T H E S Y M B O L M A R K O F T H I S S C H E M E T I C D I A G R A M I N C O R P O R A T E SS P E C I A L F E A T U R E S I M P O R T A N T F O R P R O T E C T I O N F R O M X - R A D I A T I O N .F I L R E A N D E L E C T R I C A L S H O C K H A Z A R D S , W H E N S E R V I C I N G I F I S E S S ...
Page 21 - * O p t i o n n a m e o f t h i s p a g e : C I _ S L O T
T H E S Y M B O L M A R K O F T H I S S C H E M E T I C D I A G R A M I N C O R P O R A T E SS P E C I A L F E A T U R E S I M P O R T A N T F O R P R O T E C T I O N F R O M X - R A D I A T I O N .F I L R E A N D E L E C T R I C A L S H O C K H A Z A R D S , W H E N S E R V I C I N G I F I S E S S ...
Page 22 - E T H E R N E T; ETHERNET
T H E S Y M B O L M A R K O F T H I S S C H E M E T I C D I A G R A M I N C O R P O R A T E SS P E C I A L F E A T U R E S I M P O R T A N T F O R P R O T E C T I O N F R O M X - R A D I A T I O N .F I L R E A N D E L E C T R I C A L S H O C K H A Z A R D S , W H E N S E R V I C I N G I F I S E S S ...
Page 23 - I R / L E D a n d c o n t r o l f o r o n . y ’ 1 2 s u b w i t h o u t I R - O U T .
T H E S Y M B O L M A R K O F T H I S S C H E M E T I C D I A G R A M I N C O R P O R A T E SS P E C I A L F E A T U R E S I M P O R T A N T F O R P R O T E C T I O N F R O M X - R A D I A T I O N .F I L R E A N D E L E C T R I C A L S H O C K H A Z A R D S , W H E N S E R V I C I N G I F I S E S S ...
Page 25 - D V B - S 2 L N B P a r t A l l e g r o
T H E R M A L T H E S Y M B O L M A R K O F T H I S S C H E M E T I C D I A G R A M I N C O R P O R A T E SS P E C I A L F E A T U R E S I M P O R T A N T F O R P R O T E C T I O N F R O M X - R A D I A T I O N .F I L R E A N D E L E C T R I C A L S H O C K H A Z A R D S , W H E N S E R V I C I N G ...
Page 27 - S 7 L R c o r e 1 . 2 V v o l t; A M P _ V C C C o n t r o l
THERMAL T H E R M A L THERMAL THERMAL THERMAL T H E S Y M B O L M A R K O F T H I S S C H E M E T I C D I A G R A M I N C O R P O R A T E SS P E C I A L F E A T U R E S I M P O R T A N T F O R P R O T E C T I O N F R O M X - R A D I A T I O N .F I L R E A N D E L E C T R I C A L S H O C K H A Z A R ...
Page 31 - U S B 1 _ D I O D E S
U S B D O W N S T R E A M USB DOWN STREAM T H E S Y M B O L M A R K O F T H I S S C H E M E T I C D I A G R A M I N C O R P O R A T E SS P E C I A L F E A T U R E S I M P O R T A N T F O R P R O T E C T I O N F R O M X - R A D I A T I O N .F I L R E A N D E L E C T R I C A L S H O C K H A Z A R D S ...
Page 33 - F u l l S c a r t
T H E S Y M B O L M A R K O F T H I S S C H E M E T I C D I A G R A M I N C O R P O R A T E SS P E C I A L F E A T U R E S I M P O R T A N T F O R P R O T E C T I O N F R O M X - R A D I A T I O N .F I L R E A N D E L E C T R I C A L S H O C K H A Z A R D S , W H E N S E R V I C I N G I F I S E S S ...
Page 37 - Contents of LCD TV Standard Repair Process
Contents of LCD TV Standard Repair Process No. Error symptom (High category) Error symptom (Mid category) Page Remarks 1 A. Video error No video/Normal audio 1 2 No video/No audio 2 3 Tuning fail, Picture broken/ Freezing 3, 4 4 Color error 5 5 Vertical/Horizontal bar, residual image, light spot, ex...
Page 38 - Continue to the next page
Contents of LCD TV Standard Repair Process Detail Technical Manual No. Error symptom Content Page Remarks 1 A. Video error_ No video/Normal audio Check LCD back light with naked eye A1 2 LED driver B+ 24V measuring method A2 3 Check White Balance value A3 4 Power Board voltage measuring method A4 6 ...
Page 39 - Standard Repair Process; LCD TV
Normal audio Y N Move to No video/No audio No videoNormal audio Check Back LightOn with naked eye On Y N Check Power Board12v,3.5v etc. Normal voltage Y N Replace T-con Board or module Repair Power Board or parts Check Power Board 24v output Normalvoltage Y Replace Inverter or module N Repair Power ...
Page 40 - Established; Error
Normal voltage? Check various voltages of Power Board ( 3.5V,12V,20V or 24V…) No Video/No audio Check and replace MAIN B/D Y Replace Power Board and repair parts N End Standard Repair Process A. Video error No video/ No audio ☞ A4 Established date Revised date 2/14 LCD TV Error symptom 2012 . 01 .14...
Page 43 - Check; RGB
Color error? Y N ※ Check and replace Link Cable(LVDS) and contact condition Y N Replace Main B/D Color error? Check error color input mode Check color by input-External Input-COMPONENT - RGB - HDMI/DVI Y External device /Cable normal External Input/ Component error Check external device andcable Y E...
Page 44 - External device screen error-Color error; Check Test pattern
Screen normal? N Y Check external device connection condition Y N Check and replace Link Cable Normal? Y Screen normal? Replace module Check color condition by input-External Input-Component - RGB - HDMI/DVI End Vertical/Horizontal bar, residual image, light spot Request repair for external device A...
Page 46 - * Please refer to the all cases which
B. Power error Off when on, off while viewing, power auto on/off Error? N Y Check Power OffMode Fix A/C cord & Outlet and check each 3 phase out Check A/C cord Check for all 3- phase power out Check outlet Replace Main B/D CPU Abnormal (If Power Off mode is not displayed)Check Power B/D voltage ...
