LG PF-43A20 Service Manual
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LG PF-43A20 Service Manual

LG PF-43A20 Service Manual

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All manuals and user guides at all-guides.com
COLOR TV
SERVICE MANUAL
CHASSIS : MP-87B
MODEL : PF-43A20
CAUTION
BEFORE SERVICING THE CHASSIS,
READ THE SAFETY PRECAUTIONS IN THIS MANUAL.

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  • Page 1 All manuals and user guides at all-guides.com COLOR TV SERVICE MANUAL CHASSIS : MP-87B MODEL : PF-43A20 CAUTION BEFORE SERVICING THE CHASSIS, READ THE SAFETY PRECAUTIONS IN THIS MANUAL.

  • Page 2: Table Of Contents

    All manuals and user guides at all-guides.com CONTENTS Contents ......................2 Safety Precautions ..................3 Servicing Precautions ..................4 Specifications ....................6 Control Descriptions ..................8 Alignment/Test Point Location Guide............11 Adjustment......................14 Troubleshooting .....................19 Component Location Guide .................26 Printed Circuit Board ..................27 Block Diagram ....................34 Wiring Diagram....................36 Exploded View ....................

  • Page 3: Safety Precautions

    All manuals and user guides at all-guides.com SAFETY PRECAUTIONS IMPORT ANT SAFETY NOTICE Many electrical and mechanical parts in this chassis have special safety-related characteristics. These parts are identified by the Schematic Diagram and Replacement Parts List. 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.

  • Page 4: Servicing Precautions

    All manuals and user guides at all-guides.com SERVICING PRECAUTIONS CAUTION: Before servicing receivers covered by this service transistors and semicounductor "chip" components. The manual and its supplements and addenda, read and follow the following techniques should be used to help reduce the SAFETY PRECAUTIONS on page 3 of this publication.
  • Page 5 All manuals and user guides at all-guides.com c. Qulckly move the soldering iron tip to the junction of the Fuse and Conventional Resistor component lead and the printed circuit foil, and hold it Removal/Replacement there only until the solder flows onto and around both the 1.

  • Page 6: Specifications

    All manuals and user guides at all-guides.com SPECIFICATIONS NOTE : Specifications and others are subject to change without notice for improvement. Video input system: Power requirements : ¡ ¡ Multi 26 System 100-270 Vac, 50/60HZ (Refer to Table 1) Intermediate Frequency Power consumption : ¡...
  • Page 7 All manuals and user guides at all-guides.com T able 1 : Receiving System (26 System) Receiving System Receiving Channel Function P P A A L L - - B B P P A A L L - - G G V V H H F F B B a a n n d d P P A A L L - - I I PAL/SECAM-B...

  • Page 8: Control Descriptions

    9 or 4 PLAY sub pictures. P/STILL STOP 5. PSM (Picture Status Memory) recalls your preferred picture setting. 6. SSM (Sound Status Memory) recalls your preferred sound setting. 7. VCR BUTTONS (option) control a LG video cassette recorder. - 8 -...
  • Page 9 All manuals and user guides at all-guides.com 8. DUAL selects the language during dual language broadcast. selects mono sound during stereo broadcasts. POWER MUTE 9. TV/AV I/II selects TV or AV mode. 10. MENU selects a menu. TV/AV 11. ¡ª/¡ (Programme Up/Down) TEXT MENU switches the set on from standby.
  • Page 10 All manuals and user guides at all-guides.com Front panel AV 2 TV/AV MENU S-VIDEO VIDEO L/MONO AUDIO 1. MAIN POWER (on the side of TV) 7. ¡ª/¡ (Programme Up/Down) switches the set on or off. switches the set on from standby. selects a programme or a menu item.

  • Page 11: Alignment/Test Point Location Guide

    All manuals and user guides at all-guides.com ALIGNMENT/TEST POINT LOCATION GUIDE SIGNAL Board (Component side) - 11 -...
  • Page 12 All manuals and user guides at all-guides.com DEFLECTION Board (Component side) - 12 -...
  • Page 13 All manuals and user guides at all-guides.com IF (Component side) PIP (Component side) CPT Board (Component side) VR902B VR902R VR902G - 13 -...

  • Page 14: Adjustment

    All manuals and user guides at all-guides.com ADJUSTMENT INSTRUCTIONS § Safety Precautions ¡ Main VCO (Voltage Controlled Oscillator) Adjustment 1. It is safe to adjust after using insulating transformer between the power supply line and chassis input to prevent Test Point : the risk of electric shock and protect the instrument.
  • Page 15 All manuals and user guides at all-guides.com ¡ RF AGC (Auto Gain Control) Adjustment ¡ Cut-off Adjustment Test Point : J104/ J106 NOTE : This adjustment should be performed after warming up for 15 minutes at least. Adjust : VRI1 / VRP1 Observing Display Test Point : The RF AGC control (VRI1/ VRP1 ) was aligned at the time of...
  • Page 16 All manuals and user guides at all-guides.com RASTER SLANT/POSITION, FOCUS & CONVERGENCE ADJUSTMENT Caution : ¡ Lens and Electrical Focus Adjustment These adjustments have been factory aligned. Do not attempt 1. Preliminary steps to temper with these alignments. However, the effects of 1) The electrical focus, the raster slant and position must be adjacent receiver components, or replacement of picture tube provisional alignment.
  • Page 17 All manuals and user guides at all-guides.com 2) Horizontal Phase Adjustment. 4. Blue lens Adjustment Press the volume ¢‚/¢”button and move the convex part 1) Turn the lens until the chromatic aberration changed to the middle of TV screen. purple to green which of 3.5 Cross-Hatch part from picture's center toward left.
  • Page 18 All manuals and user guides at all-guides.com 6. Red Convergence Adjustment 1) Press TV/AV button and select the red cursor. 2) If necessary, cover B lens. 3) Adjust as same as the green convergence adjustment and coincide the red pattern with the green pattern. 7.

  • Page 19: Troubleshooting

    All manuals and user guides at all-guides.com TROUBLESHOOTING NO PICTURE/ NO COLOR Is the CVBS signal at pin 4 of P101A normal? Check IF Board Is the CVBS signal at Pin 40 of IC201 normal? Check/Replace IC201 Is the Y signal at Pin 3 of IC1D normal? Check/Replace IC1D, Q202...
  • Page 20 All manuals and user guides at all-guides.com NO PIP In case of PIP (AV) In case of PIP (RF) Is there video signal at Is there CVBS signal at pin 29 of IC201? pin 24 of ICP3? Check/Replace IC201 Check Check I C Bus TUNER/IF parts...
  • Page 21 All manuals and user guides at all-guides.com NO TELETEXT Check the voltage of CT75(+) Abnormal Normal Abnormal Check the 12V line Check the voltage of CT76(+) to be correct Check/Replace ICT75, PT75 4.8~ 5.2V Check if the video signal inputs at pin 8 of ICT74. Check if the video signal inputs at the pin 40 of IC201.
  • Page 22 All manuals and user guides at all-guides.com NO PICTURE/NO SOUND (RASTER OK) Does the Auto search operate normal? Is the CVBS signal at Check the voltage Pin 4 of P101A normal? of Tuner (33V, 5V) Check/Replace Check IF Board ZD101, ZD102, R106, R108 GO TO Check pins 20,21,...
  • Page 23 All manuals and user guides at all-guides.com NO SOUND (PICTURE OK) Check Sound system of station MENU OSD (Manual Programme) BG/I/DK Is the voltage at pin 25 Is the voltage at Pin 25 of IC1 0V(Low)? of IC1 5V(High)? Is the SIF signal at Pin 24 of ICI1 normal? Check/Replace ICI1...
  • Page 24 All manuals and user guides at all-guides.com NO RASTER Check +B voltage at R406. Normal Open Is the voltage at Check F801A Pin 3 of IC501 9V? Check 5V, 9V, Check/Replace 12V lines F801A, D821, IC825 Does the square Check the voltage waveform from pin 4 of of C809(+) IC501 appear?
  • Page 25 All manuals and user guides at all-guides.com INCORRECT CONVERGENCE Does the static convergence correct? Incorrect Dynamic Incorrect Static Check the input voltage at Readjust static convergence by remote controller P82PD. Normal Abnormal Not controlled Controlled Check pulse pin 125 Check voltage on the Are there pulse signal of IC2051 (4MHz) SMPS PCB...

  • Page 26: Component Location Guide

    All manuals and user guides at all-guides.com COMPONENT LOCATION GUIDE(SIGNAL) R102..B1 R516 ..D5 R658..B4 AC1 ..F1 C471..F5 C621..B4 D604 ..C4 P303A..F1 R23 ..G1 D605..A4 P401A ..G5 R24..F1 R103..B1 R517 ..D5 R659..A5 AR1..G1 C472..F5 C622 ..C4 C473..F5 C623..B4 D606 ..C4 P402A..F5 R25..F2 R104 ..C1 R518 ..D5...

  • Page 27: Printed Circuit Board

    All manuals and user guides at all-guides.com - 27 -...
  • Page 28 All manuals and user guides at all-guides.com - 28 -...
  • Page 29 All manuals and user guides at all-guides.com - 29 -...
  • Page 30 All manuals and user guides at all-guides.com - 30 -...
  • Page 31 All manuals and user guides at all-guides.com COMPONENT LOCATION GUIDE(DEF) R440..A1 R2032..B4 C301..B2 C432 ..C1 D410..B3 G43 ..C1 Q308 ..E4 R344..E2 G44 ..C1 Q309 ..E4 R345..E3 R441..A2 R2033..E5 C302..B2 C433..B2 D412..A2 C434..A2 D413..A1 G45 ..B1 Q310 ..A4 R346..E3 R442..A2 R2034 ..C5 C303..B3 C304..A3 C435..A2...
  • Page 32 All manuals and user guides at all-guides.com IF/MPX - 32 -...
  • Page 33 All manuals and user guides at all-guides.com AV/DCF A/V 2 - 33 -...

  • Page 34: Block Diagram

    All manuals and user guides at all-guides.com BLOCK DIAGRAM - 34 -...
  • Page 35 All manuals and user guides at all-guides.com BLOCK DIAGRAM(SIGNAL) - 35 -...

  • Page 36: Wiring Diagram

    All manuals and user guides at all-guides.com WIRING DIAGRAM POWER S/W PWB P803 P802 AV3 PWB P201PSA CONTROL PWB P202PSC DIGI-CON PCB P02A HV BLOCK P110PD P43PD P82PD FOCUS PACK "C" "A" "B" P301A GND1B GND1G "B" CRT PCB "R" CRT PCB "G"...
  • Page 37 All manuals and user guides at all-guides.com MEMO - 37 -...

  • Page 38: Exploded View

    All manuals and user guides at all-guides.com EXPLODED VIEW - 38 -...

  • Page 39: Exploded View Parts List

    SCREEN,SGS7243N 3720V00007B PANEL,RIGHT 6871VSM258A PCB ASSY,A/V3 6871VSM257A PCB ASSY,CONTROL 3720V00011E PANEL ASSY,CONTROL 3580V00007B DOOR,CONTROL 5020V00074B BUTTON,CONTROL 8KEY ABS 5020V00247A BUTTON,POWER PF-43A20 ABS . 320-070R SPRING,COIL 3091V00025C CABINET ASSY,WOOD 4980V00039A SUPPORTER,CONV.PCB 3550V00011D COVER ASSY,BOTTOM 3530V00027B GRILLE ASSY,SPEAKER 3300V00009A PLATE,CRT COVER 4980V00023A...

  • Page 40: Replacement Parts List

    0DD184009AA DIODE,SWITCHING KDS184S 85V 300MA IC2051 0IGS961200A IC,MDC9612 144QFP BK DIGITAL CONV D2201 0DD181009AB DIODE,SWITCHING KDS181 85V 300MA IC2052 0IZZVD0005F IC,PF-43A20 D-CON MICOM ASSY 44PI DIODE,SWITCHING KDS181 85V 300MA D2202 0DD181009AB 0IKE744200A IC,KIA7442P TO-92 NEGA.RESET(4.2V IC2053 0DD414809ED DIODE,DS4148 IC2054 0IZZVD0005J...
  • Page 41 All manuals and user guides at all-guides.com The components identified by mark critical for safety. LOCA. NO PART NO DESCRIPTION LOCA. NO PART NO DESCRIPTION D501 0DD414809ED DIODE,DS4148 ZD2004 0DZ120009AA DIODE,ZENER Z12BM TA 0DD414809ED DIODE,DS4148 0DZ511109AA DIODE,ZENER DTZ5.1BTT11(CHIP) D502 ZD2051 DIODE,DS4148 D503 0DD414809ED...
  • Page 42 All manuals and user guides at all-guides.com The components identified by mark critical for safety. LOCA. NO PART NO DESCRIPTION LOCA. NO PART NO DESCRIPTION Q205 0TR319809AA TR,KTC3198-TP-Y (KTC1815)KEC Q2351 0TR387500AA TR,CHIP 2SC3875S(ALY) KEC 0TR150400BA TR,CHIP 2SA1504S(ASY) KEC 0TR387500AA TR,CHIP 2SC3875S(ALY) KEC Q206 Q2352 TR,CHIP 2SC3875S(ALY) KEC...
  • Page 43 All manuals and user guides at all-guides.com The components identified by mark critical for safety. LOCA. NO PART NO DESCRIPTION LOCA. NO PART NO DESCRIPTION Q902R 0TR319809AA TR,KTC3198-TP-Y (KTC1815)KEC CP82 0CE107DF618 C,ELECTROLYTIC 100UF STD 16V M 0TR322900AA TR,KTC3229 (KTC2068),KEC 0CE477DF618 C,ELECTROLYTIC 470UF STD 16V M Q904B...
  • Page 44 All manuals and user guides at all-guides.com The components identified by mark critical for safety. LOCA. NO PART NO DESCRIPTION LOCA. NO PART NO DESCRIPTION 0CN1030F679 C,TUBULA(HIGH DIELE) 0.01MF 16V M C2034 0CN1510K519 C,TUBULA(HIGH DIELE) 150P 50V K 0CN1030F679 C,TUBULA(HIGH DIELE) 0.01MF 16V M 0CN1510K519 C,TUBULA(HIGH DIELE) 150P 50V K C101...
  • Page 45 All manuals and user guides at all-guides.com The components identified by mark critical for safety. LOCA. NO PART NO DESCRIPTION LOCA. NO PART NO DESCRIPTION C26D 0CE476DF618 C,ELECTROLYTIC 47UF STD 16V M C422 0CK22101515 C,CERAMIC(HIGH DIELE) 220P 1KV K B TP5 0CE475DK618 C,ELECTROLYTIC 4.7UF STD 50V M...
  • Page 46 All manuals and user guides at all-guides.com The components identified by mark critical for safety. LOCA. NO PART NO DESCRIPTION LOCA. NO PART NO DESCRIPTION C520 0CE106DK618 C,ELECTROLYTIC 10UF STD 50V M C814 181-014Z C,MPP 1.6KV 0.0033UF J 0CE335DK618 C,ELECTROLYTIC 3.3UF STD 50V M 0CK4710W515 C,CERAMIC(HIGH DIELE) 470PF 500V K...
  • Page 47 All manuals and user guides at all-guides.com The components identified by mark critical for safety. LOCA. NO PART NO DESCRIPTION LOCA. NO PART NO DESCRIPTION C904B 181-033T CAPACITOR 2KV B 222K TP7.5 LP17 0LA0102K119 INDUCTOR,10UH K 181-033T CAPACITOR 2KV B 222K TP7.5 0LA0102K119 INDUCTOR,10UH K C904G...
  • Page 48 All manuals and user guides at all-guides.com The components identified by mark critical for safety. LOCA. NO PART NO DESCRIPTION LOCA. NO PART NO DESCRIPTION L406 150-L01S COIL,H-LINEARITY 40UH P917G 387-A26J CONNECTOR ASSY,6P MIS 2.5MM (L=300) 150-W01D COIL,CHOKE WIDTH 3600UH 387-A24J CONNECTOR ASSY,4P MIS 2.5MM (L=300) L407...
  • Page 49 All manuals and user guides at all-guides.com The components identified by mark critical for safety. LOCA. NO PART NO DESCRIPTION LOCA. NO PART NO DESCRIPTION RT89 0RD4700F609 R,CARBON FILM 1/6W 5 R2020 0RS2200J607 R,METAL FILM OXIDE 220 1W 5% 0RD4700F609 R,CARBON FILM 1/6W 5 0RS0561K607...
  • Page 50 All manuals and user guides at all-guides.com The components identified by mark critical for safety. LOCA. NO PART NO DESCRIPTION LOCA. NO PART NO DESCRIPTION R274 0RD2200F609 R,CARBON FILM 1/6W 5 R351 0RD4701F609 R,CARBON FILM 4.7K 1/6W 5 0RD1001F609 R,CARBON FILM 1.0K 1/6W 5 0RD1001F609 R,CARBON FILM...
  • Page 51 All manuals and user guides at all-guides.com The components identified by mark critical for safety. LOCA. NO PART NO DESCRIPTION LOCA. NO PART NO DESCRIPTION R434 0RS0152J607 R,METAL FILM OXIDE 15 1W 5% TA62 R510 0RD1001F609 R,CARBON FILM 1.0K 1/6W 5 0RS4700K607 R,METAL FILM OXIDE 470 2W 5% 0RD1001F609...
  • Page 52 All manuals and user guides at all-guides.com The components identified by mark critical for safety. LOCA. NO PART NO DESCRIPTION LOCA. NO PART NO DESCRIPTION R641 0RD1001F609 R,CARBON FILM 1.0K 1/6W 5 R841 0RS0102K607 R,METAL FILM OXIDE 10 2W 5% 0RD1001F609 R,CARBON FILM 1.0K 1/6W 5...
  • Page 53 FILTER,EMI,DSS306-93FZ103N 100V TA SG901R 165-004A SPARK GAP,AG20PT 152F-L3N/S-23 ACCESSORIES 165-004A SPARK GAP,AG20PT 152F-L3N/S-23 SG902B SG902G 165-004A SPARK GAP,AG20PT 152F-L3N/S-23 3828VA0160F MANUAL,OWNERS MP87B.LG EN 7WTX 341C . SG902R 165-004A SPARK GAP,AG20PT 152F-L3N/S-23 6710V00007W REMOTE CONTROLLER MISCELLANEOUS SWITCH SW01 140-191A SWITCH,TACT,KHH-15910 172-050Y...
  • Page 54 All manuals and user guides at all-guides.com The components identified by mark critical for safety. LOCA. NO PART NO DESCRIPTION TU151 113-243B TUNER,TUGG9-A07P(HYPER) 6174Z-6079D F.B.T,FTMPC11-T6079D T401 VA801 164-003D VARISTOR,SVC 561D-14A - 54 -...
  • Page 55 All manuals and user guides at all-guides.com VIDEO AUDIO...
  • Page 56 All manuals and user guides at all-guides.com...
  • Page 57 All manuals and user guides at all-guides.com...
  • Page 58 All manuals and user guides at all-guides.com...
  • Page 59 All manuals and user guides at all-guides.com Oct., 1998 P/NO : 3828VD0053C Printed in Korea...

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