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Symphonic LCD-B20D6 Service Manual

20" color lcd television
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SERVICE MANUAL

20" COLOR LCD TELEVISION
LCD-B20D6

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Summary of Contents for Symphonic LCD-B20D6

  • Page 1: Service Manual

    SERVICE MANUAL 20" COLOR LCD TELEVISION LCD-B20D6...

  • Page 2: Table Of Contents

    20″ COLOR LCD TELEVISION LCD-B20D6 TABLE OF CONTENTS Specifications ................1-1 Important Safety Precautions.

  • Page 3: Specifications

    SPECIFICATIONS <TUNER> ANT. Input ------------------- 80 dBµV, Video: PAL 87.5%, Audio: 30 kHz dev (1 kHz Sin) Test Input Signal----------- 400Hz 30% modulation Description Condition Unit Nominal Limit 1. Intermediate Freq. Picture PAL-BG/I/DK 38.9 Sound PAL-BG 33.4 PAL-I 32.9 PAL-DK 32.4 2.

  • Page 4: Important Safety Precautions

    IMPORTANT SAFETY PRECAUTIONS Prior to shipment from the factory, our products are strictly inspected for recognized product safety and electrical codes of the countries in which they are to be sold. However, in order to maintain such compliance, it is equally important to implement the following precautions when a set is being serviced.

  • Page 5: Specifications

    4. Hot Chassis Warning - 7. Product Safety Notice - Some electrical and mechanical parts have special safety-related a. Some TV receiver chassis are electrically characteristics which are often not evident from connected directly to one conductor of the AC visual inspection, nor can the protection they give power cord and maybe safety-serviced without necessarily be obtained by replacing them with...
  • Page 6 Precautions during Servicing A. Parts identified by the ! symbol are critical for M. When installing parts or assembling the cabinet safety. parts, be sure to use the proper screws and Replace only with part number specified. tighten certainly. B. In addition to safety, other parts and assemblies are specified for conformance with regulations applying to spurious radiation.
  • Page 7 Safety Check after Servicing Examine the area surrounding the repaired location Chassis or Secondary Conductor for damage or deterioration. Observe that screws, parts and wires have been returned to original posi- tions. Afterwards, perform the following tests and con- Primary Circuit firm the specified values in order to verify compliance with safety standards.

  • Page 8: Standard Notes For Servicing

    STANDARD NOTES FOR SERVICING Circuit Board Indications How to Remove / Install Flat Pack-IC 1. The output pin of the 3 pin Regulator ICs is 1. Removal indicated as shown. With Hot-Air Flat Pack-IC Desoldering Machine: 1. Prepare the hot-air flat pack-IC desoldering Top View Bottom View machine, then apply hot air to the Flat Pack-IC...
  • Page 9 With Soldering Iron: With Iron Wire: 1. Using desoldering braid, remove the solder from 1. Using desoldering braid, remove the solder from all pins of the flat pack-IC. When you use solder all pins of the flat pack-IC. When you use solder flux which is applied to all pins of the flat pack-IC, flux which is applied to all pins of the flat pack-IC, you can remove it easily.
  • Page 10 2. Installation Instructions for Handling Semi- 1. Using desoldering braid, remove the solder from conductors the foil of each pin of the flat pack-IC on the CBA Electrostatic breakdown of the semi-conductors may so you can install a replacement flat pack-IC more occur due to a potential difference caused by easily.

  • Page 11: Cabinet Disassembly Instructions

    CABINET DISASSEMBLY INSTRUCTIONS 1. Disassembly Flowchart Removal Step/ This flowchart indicates the disassembly steps for the Remove/*Unhook/ Loc. Part Fig. Unlock/Release/ cabinet parts, and the CBA in order to gain access to Note Unplug/Unclamp/ item(s) to be serviced. When reassembling, follow the Desolder steps in reverse order.
  • Page 12 [2] Rear Cabinet [1] Tilt Stand Assembly Fig. D1 [11] Front Cabinet [8] Function CBA S-11 S-12 S-10 [9] Speaker [9] Speaker S-10 S-10 [4] Inverter S-13 S-12 [10] IR Sensor [7] LCD Main CBA Unit & S-10 Liquid Crystal Panel Unit [6] Tilt Stand Holder [5] Main CBA [3] Jack Holder...

  • Page 13: Wiring Diagram

    TV Cable Wiring Diagram Function CBA CLN104 To Liquid Crystal Panel Unit LCD Main CBA Unit CN106 CN311 CN312 Main CBA Inverter CBA CN103B CN102B CN101B CN301 CN404 CN304 CN103A CN101A CN102A To Liquid CN302 Crystal Panel Unit CN303 CN53 CN801 CN310 IR Sensor CBA...

  • Page 14: How To Initialize The Lcd Television

    HOW TO INITIALIZE THE LCD TELEVISION To put the program back at the factory-default, initialize the LCD television as the following procedure. How to initialize the LCD television: 1. Turn the power on. (Use main power on the TV unit.) 2.

  • Page 15: Electrical Adjustment Instructions

    ELECTRICAL ADJUSTMENT INSTRUCTIONS General Note: 1. Initial Setting “CBA” is abbreviation for “Circuit Board Assem- General bly.” Enter the Service mode. NOTE: Electrical adjustments are required after replacing Set the each initial data as shown on table 1 below. circuit components and certain mechanical parts. It is Table 1: Initial Data important to perform these adjustments only after all repairs and replacements have been completed.

  • Page 16: Flicker Adjustment

    2. Flicker Adjustment BUTTON DATA ITEM (on the remote 1. Enter the Service mode. (See page 6-1.) VALUE control) 2. Press [2] button on the remote control unit. C-BRT(NTSC) The following screen appears. C-CNT(NTSC) C-CLR-R(NTSC) MENU → 9 C-CLR-B(NTSC) VCOM C-TNT(NTSC) C-SHR(NTSC) BRIGHT...

  • Page 17: White Balance Adjustment

    The following adjustment normally are not 6. [AV1(RGB)]----(APL 80%) Press “6” button to select “C-DB(C/D/S-2)” for Blue attempted in the field. Only when replacing the adjustment. Press “4” button to select “C-DR(C/D/ LCD Panel then adjust as a preparation. S-2)” for Red adjustment.When “x” value and “y” value are not within specification, adjust “C-DB(C/ 3.

  • Page 18: Block Diagrams

    BLOCK DIAGRAMS System Control Block Diagram L4633BLS...
  • Page 19 IF/Video Block Diagram L4633BLIF...
  • Page 20 Audio Block Diagram L4633BLA...
  • Page 21 LCD Block Diagram L4633BLLCD...
  • Page 22 Power Supply Block Diagram L4633BLP...
  • Page 23 LCD Backlight Block Diagram L4633BLLB...

  • Page 24: Schematic Diagrams / Cba's And Test Points

    SCHEMATIC DIAGRAMS / CBA'S AND TEST POINTS Standard Notes Many electrical and mechanical parts in this chassis have special characteristics. These characteristics often pass unnoticed and the protection afforded by them cannot necessarily be obtained by using replacement components rated for higher voltage, wattage, etc. Replacement parts that have these special safety characteristics are identified in this manual and its supplements;...
  • Page 25 LIST OF CAUTION, NOTES, AND SYMBOLS USED IN THE SCHEMATIC DIAGRAMS ON THE FOLLOWING PAGES: 1. CAUTION: FOR CONTINUED PROTECTION AGAINST FIRE HAZARD, REPLACE ONLY WITH THE SAME TYPE FUSE. 2. CAUTION: Fixed Voltage (or Auto voltage selectable) power supply circuit is used in this unit. If Main Fuse (F601) is blown, first check to see that all components in the power supply circuit are not defective before you connect the AC plug to the AC power supply.
  • Page 26 Main 1/4 Schematic Diagram L4633SCM1...
  • Page 27 Main 2/4 Schematic Diagram VOLTAGE CHART CN103A Pin No. Voltage L4633SCM2...
  • Page 28 Main 3/4 Schematic Diagram CAUTION ! NOTE: CAUTION ! For continued protection against fire hazard, The voltage for parts in hot circuit is measured using Fixed voltage (or Auto voltage selectable) power supply circuit is used in this unit. replace only with the same type fuse. hot GND as a common terminal.
  • Page 29 Main 4/4 & IR Sensor Schematic Diagram VOLTAGE CHART CN102A Pin No. Voltage L4633SCM4...
  • Page 30 Function Schematic Diagram L4633SCF...
  • Page 31 Inverter Schematic Diagram L4633SCINV...
  • Page 32 LCD Main 1/2 Schematic Diagram L4633SCL1...
  • Page 33 LCD Main 2/2 Schematic Diagram 8-10 L4633SCL2...
  • Page 34 Main CBA Top View CAUTION ! CAUTION ! Because a hot chassis ground is present in the power supply circut, an isolation transformer must be used. For continued protection against fire hazard, Fixed voltage (or Auto voltage selectable) power supply circuit is used in this unit. If Main Fuse (F601) is blown , check to see that all components in the power supply Also, in order to have the ability to increase the input replace only with the same type fuse.
  • Page 35 Main CBA Bottom View CAUTION ! CAUTION ! Because a hot chassis ground is present in the power Fixed voltage (or Auto voltage selectable) power supply circuit is used in this unit. supply circut, an isolation transformer must be used. For continued protection against fire hazard, replace only with the same type fuse.
  • Page 36 Function CBA Top View IR Sensor CBA Top & Bottom View BL4520F01012-3 Function CBA Bottom View BL2601F01031-1 8-13...
  • Page 37 Inverter CBA Top View Inverter CBA Bottom View 8-14 BL2500F01021...

  • Page 38: Waveforms

    WAVEFORMS WF1 ~ WF8 = Waveforms to be observed at Waveform check points. (Shown in Schematic Diagram.) Input: PAL Color Bar Signal (with 1kHz Audio Signal) Pin 14 of IC801 Pin 9 of CN103A Pin 3 of CN103A AUDIO 0.1V 0.5ms CVBS2 0.2V...
  • Page 39 WF9 ~ WF14 = Waveforms to be observed at Waveform check points. (Shown in Schematic Diagram.) Input: PAL Color Bar Signal (with 1kHz Audio Signal) R904 R997 WF12 10µs CTKH 20ns R907 R902 WF10 WF13 STH1 1µs STV1 R901 R905 WF11 WF14 20µs...

  • Page 40: Wiring Diagram

    WIRING DIAGRAMS 10-1 L4633WI...

  • Page 41: Exploded View

    EXPLODED VIEWS Cabinet Function CBA SP802 CLN310 CLN801 SP801 IR Sensor CBA Inverter CBA LCD Main CBA Unit & Liquid Crystal Panel Unit See Electrical Parts List for parts with this mark. Main CBA AC601 11-1 L4633CEX...
  • Page 42 Packing X2-1 Packing Tape Tape Packing Tape Packing Tape Packing Tape Some Ref. Numbers are not in sequence. 11-2 L4633PEX...

  • Page 43: Mechanical Parts List

    MECHANICAL PARTS LIST PRODUCT SAFETY NOTE: Products marked with a PARTS produced in EU ! have special characteristics important to safety. Before replacing any of these components, read carefully the product safety notice in this service Ref. No. Description Part No. manual.

  • Page 44: Electrical Parts List

    ELECTRICAL PARTS LIST PRODUCT SAFETY NOTE: Products marked with a Ref. No. Description Part No. ! have special characteristics important to safety. C503 ELECTROLYTIC CAP . 220µF/16V M H7 or CE1CMASSL221 Before replacing any of these components, read ELECTROLYTIC CAP . 220µF/16V M H7 CE1CMASSM221 carefully the product safety notice in this service C504...
  • Page 45 Ref. No. Description Part No. Ref. No. Description Part No. C645 ELECTROLYTIC CAP . 330µF/6.3V M H7 or CE0KMAVSL331 C730 CHIP CERAMIC CAP .(1608) B K 0.047µF/50V CHD1JK30B473 ALUMINUM ELECTROLYTIC CAP 330µF/6.3V CE0KMAVSM331 C742 ELECTROLYTIC CAP . 47µF/16V M or CE1CMASDL470 ELECTROLYTIC CAP .
  • Page 46 Ref. No. Description Part No. Ref. No. Description Part No. C833 CHIP CERAMIC CAP .(1608) CH J 22pF/50V CHD1JJ3CH220 ZENER DIODE DZ-18BSBT265 NDTB00DZ18BS C834 CHIP CERAMIC CAP .(1608) CH J 68pF/50V CHD1JJ3CH680 D404 SWITCHING DIODE 1SS400 or QD1Z001SS400 C835 CHIP CERAMIC CAP .(1608) CH J 68pF/50V CHD1JJ3CH680 SWITCHING DIODE KDS160E-RTK/P ND1ZKDS160EP...
  • Page 47 Ref. No. Description Part No. Ref. No. Description Part No. D645 SWITCHING DIODE 1SS400 or QD1Z001SS400 VOLTAGE REGULATOR KA7805A NSZBA0SF3052 SWITCHING DIODE KDS160E-RTK/P ND1ZKDS160EP IC781 IC SWITCH TC4053BF(EL N F) QSZBA0TTS163 D646 SWITCHING DIODE 1SS133(T-77) or QDTZ001SS133 IC801 IC AN17812A QSZBA0SMS017 SWITCHING DIODE 1N4148 NDTZ001N4148...
  • Page 48 Ref. No. Description Part No. Ref. No. Description Part No. CARBON RES. 1/4W J 100 Ω TRANSISTOR 2SC2785(J) or QQSJ02SC2785 R509 RCX4JATZ0101 CARBON RES. 1/4W J 4.7k Ω TRANSISTOR KTC3199-GR-AT/P or NQS4KTC3199P R510 RCX4JATZ0472 CHIP RES. 1/10W J 1.5k Ω or TRANSISTOR KTC3198-GR-AT/P NQS4KTC3198P R511...
  • Page 49 Ref. No. Description Part No. Ref. No. Description Part No. CHIP RES.(1608) 1/10W F 3.9k Ω or RES CHIP 1608 1/10W J 4.7k Ω RRXAFR5Z3901 RRXA472YF002 RES CHIP 1608 1/10W F 3.90k Ω CHIP RES.(1608) 1/10W 0 Ω or RTW3901YF002 R726 RRXAZR5Z0000 CHIP RES.
  • Page 50 Ref. No. Description Part No. Ref. No. Description Part No. CHIP RES. 1/10W J 18k Ω or RES CHIP 1608 1/10W J 1.0k Ω R778 RRXAJR5Z0183 RRXA102YF002 RES CHIP 1608 1/10W J 18k Ω CHIP RES. 1/10W J 1k Ω or RRXA183YF002 R872 RRXAJR5Z0102...
  • Page 51 Ref. No. Description Part No. Ref. No. Description Part No. CHIP RES.(1608) 1/10W 0 Ω or RES CHIP 1608 1/10W J 2.7k Ω JS707 RRXAZR5Z0000 RRXA272YF002 RES CHIP 1608 1/10W J 0 Ω CHIP RES. 1/10W J 4.7k Ω or RRXA000YF002 RRXAJR5Z0472 CHIP RES.(1608) 1/10W 0 Ω...
  • Page 52 Ref. No. Description Part No. Ref. No. Description Part No. ELECTROLYTIC CAP 22µF/50V M CE1JMASTM220 D333 SWITCHING DIODE 1SS133(T-77) QDTZ001SS133 C332 CHIP CERAMIC CAP .(1608) B K 0.01µF/50V CHD1JK30B103 D334 SWITCHING DIODE 1SS133(T-77) QDTZ001SS133 C341 CAP CHIP 5pF 3KV C XC or CA3F5R05M016 D341 SWITCHING DIODE 1SS133(T-77)
  • Page 53 Ref. No. Description Part No. Ref. No. Description Part No. CHIP RES. 1/10W J 10k Ω or TRANSISTOR KTC3198-GR-AT/P NQS4KTC3198P R333 RRXAJR5Z0103 RES CHIP 1608 1/10W J 10k Ω Q341! FET MOS SMD HAT2215R01-EL-E QF2ZHAT2215R RRXA103YF002 CHIP RES. 1/10W J 15k Ω or Q342 TRANSISTOR 2SC2785(F) or QQSF02SC2785...
  • Page 54 Ref. No. Description Part No. RES CHIP 1608 1/10W J 10k Ω RRXA103YF002 CHIP RES. 1/10W J 10k Ω or R377 RRXAJR5Z0103 RES CHIP 1608 1/10W J 10k Ω RRXA103YF002 MISCELLANEOUS JS326 PCB JUMPER D0.6-P5.0 JW5.0T JS346 PCB JUMPER D0.6-P5.0 JW5.0T JS366 PCB JUMPER D0.6-P5.0...
  • Page 55 LCD-B20D6 L4633BD 2006-09-05...

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