Page 1: Table Of Contents
LC-20B2UA SERVICE MANUAL S12E5LC20B2UA LCD COLOUR TELEVISION LC-20B2UA MODEL In the interests of user-safety (Required by safety regulations in some countries) the set should be restored to its original condition and only parts identical to those specified should be used.
Page 2: Important Service Safety Precaution
LC-20B2UA IMPORTANT SERVICE SAFETY PRECAUTION Ë Service work should be perfomed only by qualified service technicians who are thor- oughly familiar with all safety checks and the servicing guidelines which follow: ground, such as electrical conduit or electrical ground WARNING connected to an earth ground.
Page 3 LC-20B2UA PRECAUTIONS A PRENDRE LORS DE LA REPARATION Ë Ne peut effectuer la réparation qu' un technicien spécialisé qui s'est parfaitement accoutumé à toute vérification de sécurité et aux conseils suivants. conduite électrique ou une prise de terre branchée à la AVERTISSEMENT terre.
Page 4: Specifications
LC-20B2UA Specifications Items LC-20B2UA Model LCD panel 19.7” TFT LCD Number of dots 921,600 dots VGA Video color systems N358, N443, PAL, PAL-M, PAL-N, SECAM, PAL-60 Destination USA/Latin A/Twn TV Standard (CCIR) NTSC/PAL-M/PAL-N TV function TV Tuning System PLL 181 ch.
Page 5 LC-20B2UA Precautions for using lead-free solder 1 Employing lead-free solder "Main PWB" of this model employs lead-free solder. The LF symbol indicates lead-free solder, and is attached on the PWBs and service manuals. The alphabetical character following LF shows the type of lead-free solder.
Page 6: Operation Manual
LC-20B2UA Operation Manual...
Page 7 LC-20B2UA...
Page 8: Dimensions
LC-20B2UA Dimensions /630 /403 /379 /107.3 /72.6 VIDEO AV-IN1 AUDIO VIDEO AV-IN2/OUT S-VIDEO AUDIO COMPONENT H E A D PHONE ANT. AUDIO POWER INPUT DC13V /60.8 /229.4 (Unit: inch/mm)
Page 9: Removing Of Major Parts
LC-20B2UA REMOVING OF MAJOR PARTS 1. Remove the two back covers. 2. Remove the table stand fixing screws (4 pcs.). 3. Remove the cabinet B fixing screws (14 pcs.) and detach the cabinet. : XBBSF30P06000, : XEBSF40P16000) 4. Remove the reinforcement angle fixing screws (4 pcs.).
Page 10 LC-20B2UA 6. Remove the main PWB fixing screws (3 pcs.). 7. Remove the inverter-A PWB fixing screws (2 pcs.). 8. Remove the inverter-B PWB fixing screws (1 pc.). 9. Remove the chassis Frame-A fixing screws (3 pcs.). 10. Undo the hooks and slide the chassis frame B out of position. Take out the terminal PWB.
Page 11 LC-20B2UA » Precautions in handling the LCD panels 1. Work in a clean room (with humidities below 50%). 2. Be sure to wear an anti-static armband. 3. Handle the panels on an electroconductive mat. 4. Be careful not to fall, shake and shock the panels.
Page 12: Adjusting Procedure Of Each Section
LC-20B2UA ADJUSTING PROCEDURE OF EACH SECTION The best adjustment is made before shipping. If any position deviation is found or after part replace is performed, adjust as follows. 1. Preparation for Adjustments (1)Use the exclusive-use AC adapter or stable DC power supply.
Page 13 LC-20B2UA 4. Adjustments Adjustment Adjusting conditions Adjusting method 1. Adjust the "B+ Adj" value to 1. Connect the DC voltmeter to B+ Adjustment 5.0 ±0.02V with R3760. Make exact pin 2 of P3702. (R3760) adjustment of the 5.00 V level because it will be the reference for all the other supply voltages.
Page 14 LC-20B2UA Adjustment Adjusting conditions Adjusting method 1. Call up the adjustment process menu If the wrong data has been sent: PROM data write and get Page 6 displayed onscreen. 1. Initialize the E PROM. (Take the 2. Enter “A40000002681” for the “I2C special mode setting procedure (1).)
Page 15 LC-20B2UA Test patterns in adjustment process mode [1] IC801 (Video decoder) test patterns 1-1. Getting the test patterns displayed Put the screen in AV1, AV2 or COMPONENT but keep out any signal. Call the adjustment process mode, select “TEST PATTERN” in the 3rd line of page 7, make the settings 1 thru 6, and the following test patterns show up.
Page 16 LC-20B2UA Pin functions of microprocessor IC (IC2001) RH-IXA154WJZZQ Pin name Function Pin name Function V HOLD Closed caption Adjustment process AV/SY/DY2 Closed caption US CCD input select MAIN SW FSMUTE Main switch ON[H]/OFF[L] Front mute TIMELED RSMUTE Off timer LED light-up...
Page 17 LC-20B2UA Adjustment process mode menus at a glance Page Item Initial setting Function Adjust/modify Basic settings INCH SIZE Inch unit select Adjustment MODEL B2UA Model number SYSTEM N358 Color system select NTSC PWN FREQ Dimmer frequency setting PAL PWM FREQ...
Page 18 LC-20B2UA Page Item Initial setting Function Adjust/modify Video adjustments (VPC settings) I2C DATA C bus control IC data write & read IC2 DATA WAIT Write & read execution Chroma band pass setting NOSEL Comb filter setting Comb filter setting Comb filter setting...
Page 19 LC-20B2UA Page Item Initial setting Function Adjust/modify Video adjustments (TV, composite & S video) PAL AV COLOR 2500 Color density setting (composite, S video) PAL AV TINT Color tone setting (composite, S video) PAL BRIGHTNESS Brightness setting (TV, composite, S video)
Page 20 LC-20B2UA Page Item Initial setting Function Adjust/modify Search AFT reference settings & LCD controller settings (NTSC) AFT UP AFT reference voltage AFT DOWN AFT reference voltage NTSC 01 Initial settings NTSC 02 Various settings NTSC 03 RCUTOFF NTSC 04 GCUTOFF...
Page 21 LC-20B2UA Page Item Initial setting Function Adjust/modify Gradation & COM settings V255 Gradation power reference voltage V255 BIAS Gradation power reference voltage V235 Gradation power reference voltage V235 BIAS Gradation power reference voltage V176 Gradation power reference voltage Change it to "130".
Page 22: Trouble Shooting Table
LC-20B2UA TROUBLE SHOOTING TABLE...
Page 23 LC-20B2UA TROUBLE SHOOTING TABLE (Continued)
Page 24 LC-20B2UA TROUBLE SHOOTING TABLE (Continued)
Page 25 LC-20B2UA TROUBLE SHOOTING TABLE (Continued)
Page 26: Chassis Layout
LC-20B2UA CHASSIS LAYOUT MAIN Unit (Side A) MAIN Unit (Side B)
Page 27 LC-20B2UA OPERATION Unit INVERTER-A Unit TERMINAL Unit INVERTER-B Unit R/C RECEIVER Unit...
Page 28: Block Diagram
LC-20B2UA LC-20B2UA BLOCK DIAGRAM TERMINAL UNIT MAIN UNIT TV-V TUNER Y and C 3D Y/C REGULATOR SYOUT, SCOUT YO, CO TU3201 SWITCH SEPARATOR IC7102 IC7101 IC7001 IC7701 SIF-AMP. IC7002 Q3201 Q3202 V1SY,V1SC RESET SY, SC IC7004 S-VIDEO L1, R1 INPUT...
Page 29: Description Of Schematic Diagram
LC-20B2UA DESCRIPTION OF SCHEMATIC DIAGRAM [Item] IMPORTANT SAFETY NOTICE: å PARTS MARKED WITH " "( ) ARE Resistors INPORTANT FOR MAINTAINING THE SAFETY OF Nonindication Carbon-film resistor THE SET. Solid resistor BE SURE TO REPLACE THESE PARTS WITH Metal-oxide-film resistor...
Page 30: Schematic Diagramë Operation And R/C Receiver Unit
LC-20B2UA SCHEMATIC DIAGRAM Ë OPERATION and R/C RECEIVER Unit OPERATION Unit R/C RECEIVER Unit...
Page 31: Ë Main Unit
LC-20B2UA LC-20B2UA Ë MAIN Unit-1/5 DIGITAL 1...
Page 32 LC-20B2UA LC-20B2UA Ë MAIN Unit-2/5 DIGITAL 2...
Page 33 LC-20B2UA LC-20B2UA Ë MAIN Unit-3/5 DIGITAL 3...
Page 34 LC-20B2UA LC-20B2UA Ë MAIN Unit-4/5 DIGITAL 4...
Page 35 LC-20B2UA LC-20B2UA Ë MAIN Unit-5/5 DIGITAL 5...
Page 36: Ë Terminal Unit
LC-20B2UA LC-20B2UA Ë TERMINAL Unit-1/2 ANALOG 1...
Page 37 LC-20B2UA LC-20B2UA Ë TERMINAL Unit-2/2 ANALOG 2...
Page 38 LC-20B2UA Ë INVERTER-A Unit...
Page 39 LC-20B2UA INVERTER-B Unit...
Page 40: Printed Wiring Board Assemblies
LC-20B2UA PRINTED WIRING BOARD ASSEMBLIES Inverter-B Unit (Side-A) Inverter-A Unit (Side-A) R/C Receiver Unit (Side-A) Operation Unit (Side-A)
Page 41 LC-20B2UA Inverter-B Unit (Side-B) Inverter-A Unit (Side-B) R/C Receiver Unit (Side-B) Operation Unit (Side-B)
Page 42 LC-20B2UA Main Unit (Side-A)
Page 43 LC-20B2UA Main Unit (Side-B)
Page 44 LC-20B2UA Terminal Unit (Side-A)
Page 45 LC-20B2UA Terminal Unit (Side-B)
Page 46: Parts List
4. DESCRIPTION in USA: Contact your nearest SHARP Parts Distributor to order. in CANADA: Contact SHARP Electronics of Canada Limited For location of SHARP Parts Distributor, Please call Toll- Phone (416) 890-2100 Free; 1-800-BE-SHARP MARK: SPARE PARTS-DELIVERY SECTION MARQUE: SECTION LIVRAISON DES PIECES DE RECHANGE Ref.
Page 47 LC-20B2UA Ref. No. Part No. Description Code Ref. No. Part No. Description Code DUNTKA670FE12 C405 VCKYCY1HB222K J 2200p 50V Ceramic C406 VCKYTV1AB105K Ceramic MAIN UNIT (Continued) C407 VCCCCY1HH101J J 100p Ceramic C408 VCKYTV1AB105K Ceramic Q1201 VSDTC144EE/-1 J C144EE C409 VCKYTV1AB105K...
Page 48 LC-20B2UA Ref. No. Part No. Description Code Ref. No. Part No. Description Code DUNTKA670FE12 C7004 VCKYCY1EF104Z J 0.1 Ceramic C7005 VCEASM1CN106MY J 10 Electrolytic MAIN UNIT (Continued) C7006 VCKYCY1EF104Z J 0.1 Ceramic C7007 VCCCCY1HH1R0C J 1.0p Ceramic C1129 RC-EZ1339CEZZ J 220...
Page 49 LC-20B2UA Ref. No. Part No. Description Code Ref. No. Part No. Description Code DUNTKA670FE12 R1033 VRS-CY1JF000J 1/16W Metal Oxide R1034 VRS-CY1JF000J 1/16W Metal Oxide MAIN UNIT (Continued) R1102 VRS-CY1JF103F J 10k 1/16W Metal Oxide R1104 VRS-CA1JF333J J 33k 1/16W Metal Oxide...
Page 50 LC-20B2UA Ref. No. Part No. Description Code Ref. No. Part No. Description Code DUNTKA670FE12 R2056 VRS-CY1JF101J J 100 1/16W Metal Oxide R2057 VRS-CY1JF223J J 22k 1/16W Metal Oxide MAIN UNIT (Continued) R2058 VRS-CY1JF000J 1/16W Metal Oxide R2060 VRS-CY1JF103J J 10k...
Page 51: Ë Terminal Unit
LC-20B2UA Ref. No. Part No. Description Code Ref. No. Part No. Description Code DUNTKA670FE12 DUNTKB128DE03 MAIN UNIT (Continued) TERMINAL UNIT FB1202 RBLN-0006TAZZ J Ferrite Bead TUNER FB1203 RBLN-0076TAZZ J Ferrite Bead NOTE: THE PARTS HERE SHOWN ARE SUPPLIED AS AN...
Page 52 LC-20B2UA Ref. No. Part No. Description Code Ref. No. Part No. Description Code DUNTKB128DE03 C3349 VCKYCY1EF104Z J 0.1 Ceramic C3350 VCEAPF1CN106M J 10 Electrolytic TERMINAL UNIT (Continued) C3351 RC-KZ1025CEZZ Capacitor C3352 VCEAPF0JN107M J 100 6.3V Electrolytic CRYSTAL C3354 VCCCCY1HH560J J 56p...
Page 53 LC-20B2UA Ref. No. Part No. Description Code Ref. No. Part No. Description Code DUNTKB128DE03 R3369 VRS-CY1JF101J J 100 1/16W Metal Oxide R3370 VRS-CY1JF101J J 100 1/16W Metal Oxide TERMINAL UNIT (Continued) R3371 VRS-CY1JF000J 1/16W Metal Oxide R3372 VRS-CY1JF000J 1/16W Metal Oxide...
Page 54: Ë Operation Unit
LC-20B2UA Ref. No. Part No. Description Code Ref. No. Part No. Description Code DUNTKB128DE03 DUNTKB129DE03 TERMINAL UNIT (Continued) OPERATION UNIT R3718 VRS-CE3AF821JY J 820 Metal Oxide DIODES R3721 VRS-CY1JF000J 1/16W Metal Oxide D4008 RH-EX1283CEZZ J Zener Diode R3722 VRS-CY1JF000J 1/16W Metal Oxide...
Page 55: Ë Inverter-A Unit
LC-20B2UA Ref. No. Part No. Description Code Ref. No. Part No. Description Code DUNTKB133DE01 DUNTKB132DE01 INVERTER-B UNIT INVERTER-A UNIT TRANSISTORS TRANSISTORS Q6700 VSFZT1053A/-1 J FZT1053A Q6709 VSFZT1053A/-1 J FZT1053A Q6701 VSFZT1053A/-1 J FZT1053A Q6710 VSFZT1053A/-1 J FZT1053A Q6702 VS2SA1530AR-1 J A1530AR...
Page 56: Cabinet Parts Location
LC-20B2UA Ref. No. Part No. Description Code Ref. No. Part No. Description Code GCOVA2028CEKA J Back Cover CABINET PARTS LOCATION GCOVA2106CEKA J Chassis Frame GCOVA2038CEKA J Back Cover JBTN-2066CEKA J Power Button CCABA2469CE01 J Front Cabinet Ass’y QCNW-A282WJZZ J Connecting Cord Not Available –...
Page 57: Ë Cabinet And Mechanical Parts
LC-20B2UA CABINET AND MECHANICAL PARTS OPERATION Unit 1-13 1-10 1-12 1-11 INVERTER-A 1-13 1-10 MAIN PwB 1-12 INVERTER-B R/C RECEIVER Unit TERMINAL PwB...
Page 58 LC-20B2UA 3-11 3-17 3-18 3-13 3-13 3-14 3-10 3-12 3-17 3-17 3-14 3-16 3-19 3-15...
Page 59: Packing Of The Set
LC-20B2UA PACKING OF THE SET Operation Manual Cable Clamp (2 pcs.) Dry Battery (2 pcs.) AC Adapter AC Cord Antenna Cable Wireless Remote Control Buffer Material (Top) Polyethylene Bag Buffer Material (Bottom) Packing Case Not Replacement Item...
Page 60 LC-20B2UA COPYRIGHT © 2002 BY SHARP CORPORATION ALL RIGHTS RESERVED. No part of this publication may be reproduced, stored in a retrieval system, or transmitted in any form or by any means, electronic, mechanical, photocopying, recording, or otherwise, without prior written permission of the publisher.

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