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LG Flatron F720B Service Manual

Color monitor
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COLOR MONITOR

SERVICE MANUAL

CHASSIS NO. : CA-131
MODEL:
(
) **Same model for SVC
CAUTION
BEFORE SERVICING THE UNIT,
READ THE SAFETY PRECAUTIONS IN THIS MANUAL.
Website:http://biz.LGservice.com
E-mail:http://www.LGEservice.com/techsup.html
F720B
(F720BK-AL**E)
*Same looking with new chassis.
Issue Date; 2004. 03.

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Summary of Contents for LG Flatron F720B

  • Page 1: Color Monitor

    Website:http://biz.LGservice.com E-mail:http://www.LGEservice.com/techsup.html COLOR MONITOR SERVICE MANUAL CHASSIS NO. : CA-131 MODEL: F720B (F720BK-AL**E) ) **Same model for SVC CAUTION BEFORE SERVICING THE UNIT, READ THE SAFETY PRECAUTIONS IN THIS MANUAL. *Same looking with new chassis. Issue Date; 2004. 03.

  • Page 2: Table Of Contents

    CONTENTS SPECIFICATIONS ........... 2 DESCRIPTION OF BLOCK DIAGRAM....11 SAFETY PRECAUTIONS ........3 ADJUSTMENT ............13 TIMING CHART ............4 TROUBLESHOOTING GUIDE ......15 OPERATING INSTRUCTIONS ........ 5 EXPLODED VIEW..........21 CONTROL LOCATIONS ......... 7 REPLACEMENT PARTS LIST ......25 WIRING DIAGRAM ..........

  • Page 3: Safety Precautions

    SAFETY PRECAUTIONS SAFETY-RELATED COMPONENT WARNING! X-RADIATION There are special components used in this color monitor The only potential source of X-radiation is the picture tube. which are important for safety. These parts are marked However, when the high voltage circuitry is operating on the schematic diagram and the replacement properly there is no possibility of an X-radiation problem.

  • Page 4: Timing Chart

    TIMING CHART VIDEO SYNC << Dot Clock (MHz), Horizontal Frequency (kHz), Vertical Frequency (Hz), Horizontal etc... (µs), Vertical etc... (ms) >> Sync Total Period Video Active Sync Duration Front Porch Blanking Time Back Porch Resolution Mode Frequency Time (B) Polarity Sort –...

  • Page 5: Operating Instructions

    OPERAT ING INST RUCT IONS F RONT V IEW REA R V IEW AC Power Socket Power B utton See F ront Control Panel D-Sub Signal Connector F ront Control Panel Power Button Button Use these buttons to choose or adjust items in This button is used to turn the monitor ON and the on s creen dis play.

  • Page 6: Wiring Diagram

    WIRING DIAGRAM P201 P405 P501 P701 S + S P702 P402 Socket P902 Signal Cable P302 P301 - 6 -...

  • Page 7: Disassembly

    DISASSEMBLY 1. TILT/SWIVEL & BACK COVER REMOVAL 1) Set the monitor face downward. 2) Carefully remove the Tilt/Swivel by pulling it upward. 3) Pressing the latch (a), Back cover by pushing it upward. (See Figure. 1) 4) Release the latch (c). (See Figure. 2 and Tip Spec.) 5) Slide the Back Cover away from the Front Cabinet of the monitor.

  • Page 8: Block Diagram

    BLOCK DIAGRAM - 8 -...

  • Page 9: Description Of Block Diagram

    DESCRIPTION OF BLOCK DIAGRAM 1. Line Filter & Associated Circuit. This is used for suppressing noise of power input line 6. Horizontal and Vertical Oscillation. flowing into the monitor and/or some noise generated in This circuit generates the horizontal pulse and the vertical this monitor flowing out through the power input line.
  • Page 10 15. Image Rotation (Tilt) Circuit. 17. Video Output Amp Circuit. This circuit corrects the tilt of the screen by supplying the This circuit amplifies the video signal which comes from image rotation signal to the tilt coil which is attached near the video pre-amp circuit and amplified it to applied the the deflection yoke of the CRT.

  • Page 11: Adjustment

    ADJUSTMENT GENERAL INFORMATION 7) Adjust tilt as arrow keys to be the best condition. All adjustment are thoroughly checked and corrected when the monitor leaves the factory, but sometimes 8) DIST. ADJ. BALANCE command. several adjustments may be required. 9) Adjust parallelogram as arrow keys to be the best Adjustment should be following procedure and after condition.
  • Page 12 14) Set Brightness and Contrast to Max position. 5. Input EDID Data. 1) Display color 15,0 cross hatch pattern at Mode 4. 15) Set SUB-CONTRAST 127(7F) (decimal) position. 2) EEPROM Write EDID command and confirm 16) Set B-DRIVE to 100(64) at DRIVE of the alignment “EDID Write OK!!”...

  • Page 13: Troubleshooting Guide

    TROUBLESHOOTING GUIDE 1. NO POWER NO POWER (POWER INDICATOR OFF) CHECK TROUBLE IN FUSE FUSE OK? (F901) CHECK C908 VOLTAGE? TROUBLE IN (AC120V: 160VDC, D900 AC220V: 304VDC) CHECK TROUBLE IN IC901 PIN 6 Q901 WAVEFORM 2.5V CHECK TROUBLE IN D941, D942, D941, D942, D951, D951, D961, D971 D961, D971...
  • Page 14 2. NO CHARACTER NO CHARACTER CHECK TROUBLE IN IC302 P302 5V LINE PIN 18(5V) ? TROUBLE IN CHECK PC SIGNAL, IC302 PIN 5, 6, 7? P301 SIGNAL CABLE CHECK TROUBLE IN IC302 PIN 19, 20, 21 ? IC302 CHECK TROUBLE IN IC303 PIN 4 (80V) P303 12V LINE/ PIN 8 (12V) ?
  • Page 15 3. NO RASTER NO VIDEO (POWER INDICATOR ON) CHECK POWER INDICATOR AMBER DPM MODE GREEN / BLUE (NO H and/or V SYNC) or AMBER ? GREEN / BLUE CHECK TROUBLE IN D712 ANODE D712 (-160V)? CHECK TROUBLE IN G1 VOLTAGE? Q799 (-55V~-15V) CHECK...
  • Page 16 4. NO HORIZONTAL DEFLECTION NO H-DEFLECTION (ONE VERTICAL LINE) CHECK TROUBLE IN Q706? Q706 CHECK TROUBLE IN B + VOLTAGE 50V LINE (50V)? CHECK T701(FBT) PIN 2 TROUBLE IN (31KHZ 60V, Q719, Q720, D710 69KHZ 140V) ? CHECK TROUBLE IN Q705 COLLECTOR Q705 WAVEFORM?

  • Page 17: Trouble In H-Linearity

    5. TROUBLE IN H-LINEARITY UNBALANCED OF H-LIN. CHECK TROUBLE IN IC401 IC401 (MICOM) PIN 6, 7, 8 ? CHECK TROUBLE IN Q711~Q716? Q711 ~ Q716 CHECK TROUBLE IN L703? L703 Cs SIGNAL TABLE HORIZONTAL FREQUENCY(fH) 30K ~ 33.9K TROUBLE IN 34K ~ 38.9K C722, C723, C726, C729 39K ~ 43.9K...
  • Page 18 6. NO VERTICAL DEFLECTION NO V-DEFLECTION (ONE HORIZONTAL LINE) CHECK TROUBLE IN IC601 PIN 3 D951 15V LINE (15V+)? CHECK TROUBLE IN IC701 PIN 12, 13? IC701 12Pin 13Pin TROUBLE IN IC601, V-CIRCUIT - 18 -...
  • Page 19 7. TROUBLE IN OSD (ENTER BUTTON MUST BE PRESSED.) NO OSD CHECK TROUBLE IN IC302 B + 5V LINE (5V) ? DC 5V CHECK TROUBLE IN IC302 PIN 1, 24 IC401 PIN 29 (V-FBP), WAVEFORM? IC701 PIN 1LINE (H-FBP) Pin 1 Pin 24 TROUBLE IN OSD PERIPHERAL...
  • Page 20 8. TROUBLE IN DPM (NO OFF MODE.) OFF MODE FAILURE CHECK CHECK PC, IC401 (MICOM) INPUT H/V SYNC SIGNAL (PC IS NOT GOING INTO PIN 30, 31 (H/V INPUT) DPM OFF MODE) SIGNAL? H/V SYNC CHECK TROUBLE IN IC401 PIN 12, 13 X401 WAVEFORM? 12MHz...

  • Page 21: No Degaussing

    9. NO DEGAUSSING NO DEGAUSSING (DEGAUSS ON THE OSD MENU MUST BE PRESSED.) CHECK TROUBLE IN IC401 PIN 5 IC401 (MICOM) (0V)? CHECK TROUBLE IN Q953 COLLECTOR Q953 VOLTAGE? DC 15V CHECK TROUBLE IN P902 ? P902 CHECK TROUBLE IN RL901? RL901 TROUBLE IN...
  • Page 22 10. NO TILT (NO ROTATION ) NO TILT (NO ROTATION) CHECK TROUBLE IN IC401 PIN21 IC401 ( MI COM) WAVE FORM ? CHECK 15V LINE TROUBLE IN 15V LINE, 6.3V LINE AND 6.3V LINE ? CHECK TROUBLE IN Q503 EMITTER Q501~Q503 VOLTAGE ? TROUBLE IN...
  • Page 23 - 23 -...

  • Page 24: Exploded View

    6318L17021A 6318L17021A 6318L17021A 6318L17021A CDT(CIRC), M41QEU423X51NDDH LG-PHILIPS DISPLAYS 70KHZ 29.1MM FLATRON TCO RTC CDT(CIRC), M41QEU423X51NDDH LG-PHILIPS DISPLAYS 70KHZ 29.1MM FLATRON TCO RTC CDT(CIRC), M41QEU423X51NDDH LG-PHILIPS DISPLAYS 70KHZ 29.1MM FLATRON TCO RTC CDT(CIRC), M41QEU423X51NDDH LG-PHILIPS DISPLAYS 70KHZ 29.1MM FLATRON TCO RTC...

  • Page 25: Replacement Parts List

    REPLACEMENT PARTS LIST CAUTION: BEFORE REPLACING ANY OF THESE COMPONENTS, READ CAREFULLY THE SAFETY PRECAUTIONS IN THIS MANUAL. * NOTE SAFETY Mark AL ALTERNATIVE PARTS MODEL :F720BK MODEL :F720BK LOC NO PART NO. DESCRIPTION/SPECIFICATON LOC NO PART NO. DESCRIPTION/SPECIFICATON CAPACITORs C605 0CK1020W515 1000P 500V K B...
  • Page 26 MODEL :F720BK MODEL :F720BK PART NO. DESCRIPTION/SPECIFICATON LOC NO PART NO. DESCRIPTION/SPECIFICATON LOC NO C752 0CQ4721N409 0.0047UF D 100V 5% PE TP5 D309 0DSGF00019A 1N4148 GULF TP DO35 100V 0.15A 2A C753 0CK10301945 10000PF D 1KV Z F(Y5V) TR 4NSSEC 25UA C767 0CK10301945 10000PF D 1KV Z F(Y5V) TR...
  • Page 27 MODEL :F720BK MODEL :F720BK PART NO. DESCRIPTION/SPECIFICATON PART NO. DESCRIPTION/SPECIFICATON LOC NO LOC NO D902 0DR153979AA 1N5397GP TP G.I DO201AD 600V 1.5A 50A COILs&COREs 2USEC 5UA D904 0DR100009CD RGP10G-1021 TIWAN SEMI TP DO41 400V FB301 6210TCZ001J BAS3550T0(125-022J) BO SUNG 1A 30A 150NSEC 5UA RH3.5*5.0*0.8TMM AXIAL52MM D905 0DD400709CB...
  • Page 28 MODEL :F720BK MODEL :F720BK PART NO. DESCRIPTION/SPECIFICATON LOC NO PART NO. DESCRIPTION/SPECIFICATON LOC NO Q941 0TR319809AA KTC3198-Y(KTC1815) TP KEC TO92 NPN R419 0RD1004Q609 1M OHM 1/4 W (3.4) 5% TA52 Q942 0TR127309AA KTA1273-Y(KTA966A) TP KEC TO92L PNP R420 0RD3001Q609 3K 1/4W(3 5% TA52 Q951 0TR319809AA KTC3198-Y(KTC1815) TP KEC TO92 NPN...
  • Page 29 MODEL :F720BK MODEL :F720BK PART NO. DESCRIPTION/SPECIFICATON PART NO. DESCRIPTION/SPECIFICATON LOC NO LOC NO R742 0RD1003Q609 100K 1/4W(3 5% TA52 R916 0RD1002Q609 10K 1/4W(3 5% TA52 R743 0RD2702Q509 27K OHM 1/4 W(3.4) 2% TA52 R918 0RD1001Q609 1K 1/4W(3 5% TA52 R744 0RX2200K607 220 OHM 2 W 5% TA62...

  • Page 30: Pin Configuration

    PIN CONFIGURATION M24C08 Serial I C BUS EEPROM SYMBOL DESCRIPTION PSDIP8 (BN) 0.25mm Frame E0-E2 Chip Enable Input Serial Data Address Input/Output Serial Clock SO8 (MN) Write Control 150mil Width Supply Voltage TSSOP8 (DW) 169mil Width Logic Dirgram Ground TDA4867J PHILIPS 32P, SDIP SYMBOL DESCRIPTION...
  • Page 31 TDA4841PS PHLIPS 32P HFLB FOCUS XRAY HSMOD HPLL2 BSENS HCAP HREF BDRV HBUF PGND HPLL1 HDRV SGND TDA4841PS XSEL VCAP VREF EWDRV VAGC VOUT2 VSMOD VOUT1 ASCOR VSYNC HSYBC CLBL HUNLOCK Pin Configuration EHT compensaton Block Diagram via vertical size EHT compensation via horizontal size 1.2V...

  • Page 32: Schematic Diagram

    SCHEMATIC DIAGRAM This File is printed by WiseVIEW's Demo version.

  • Page 33: Printed Circuit Board

    PRINTED CIRCUIT BOARD 2. CONTROL BOARD (Solder Side) 1. CONTROL BOARD (Component Side) 3. MAIN BOARD (Component Side) 4. MAIN BOARD (Solder Side) - 34 - - 35 -...
  • Page 34 Mar. 2004 P/NO : 3828TSL086M Printed in China...

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