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LG V7550 Service Manual

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COLOR MONITOR

SERVICE MANUAL

CHASSIS NO. : CA-128
FACTORY MODEL: TV7550J
MODEL: V7550
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
*Same looking with new chassis.
Issue Date; 2003. 2.

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Summary of Contents for LG V7550

  • Page 1: Color Monitor

    Website:http://biz.LGservice.com E-mail:http://www.LGEservice.com/techsup.html COLOR MONITOR SERVICE MANUAL CHASSIS NO. : CA-128 FACTORY MODEL: TV7550J MODEL: V7550 CAUTION BEFORE SERVICING THE UNIT, READ THE SAFETY PRECAUTIONS IN THIS MANUAL. *Same looking with new chassis. Issue Date; 2003. 2.

  • Page 2: Table Of Contents

    CONTENTS SPECIFICATIONS ........... 2 TROUBLESHOOTING GUIDE ......12 SAFETY PRECAUTIONS ........3 EXPLODED VIEW........TIMING CHART ............4 EXPLODED VIEW PARTS LIST.......22 OPERATING INSTRUCTIONS ........ 5 REPLACEMENT LIST..........23 BLOCK DIAGRAM ........... 7 PIN CONFIGURATION........... 28 DESCRIPTION OF BLOCK DIAGRAM.....8 SCHEMATIC 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 Sync Video Blanking Back Front Frequency Sync Total MODE Resolution Active Polarity Sort Time(B) Porch(F) Duration(D) Porch(C) Period(E) Time(A) 640 X 480 6.356 1.907 0.636 31.469 25.422 3.813 31.778 60Hz 1.431 0.318 59.940 0.064 1.049 16.638 15.253 640 X 480 6.349...

  • Page 5: Operating Instructions

    OPERATING INSTRUCTIONS FRONT VIEW REAR VIEW AC Power Socket Signal Connector Power ON/OFF Button See Front Control Panel Front Control Panel Select Power/LED Launches on-screen displays, selects functions and Controls power to the monitor. adjustments, and exits menus and On-Screen Display. The LED on the power button is illuminated when the power is on.
  • Page 6 WIRING DIAGRAM - 6 -...

  • Page 7: Block Diagram

    BLOCK DIAGRAM Dynamic Focus Static Focus Screen(G2)

  • Page 8: Description Of Block Diagram

    DESCRIPTION OF BLOCK DIAGRAM 1. Line Filter & Associated Circuit. 6. Horizontal and Vertical Oscillation. This is used for suppressing noise of power input line This circuit generates the horizontal pulse and the vertical flowing into the monitor and/or some noise generated in pulse by taking the H and V sync signal.
  • Page 9 15. Image Rotation (Tilt) Circuit. This circuit corrects the tilt of the screen by supplying the 17. Video Output Amp Circuit. image rotation signal to the tilt coil which is attached near This circuit amplifies the video signal which comes from the deflection yoke of the CRT.

  • Page 10: Adjustment

    ADJUSTMENT 5) COMMAND → PRESET START →(Yes) command. GENERAL INFORMATION 6) DIST. ADJ. → CTRL PWM→TILT command. All adjustment are thoroughly checked and corrected when 7) Adjust tilt as arrow keys to be the best condition. the monitor leaves the factory, but sometimes several 8) DIST.
  • Page 11 16) Set SUB-CONTRAST to 100(64) position. 5. Input EDID Data. 17) Set B-DRIVE to 105(69) at DRIVE of the alignment 1) Display color 15,0 cross hatch pattern at Mode 7. program. 2) EEPROM →Write EDID command and confirm 18) Adjust R-DRIVE and G-DRIVE command to white "EDID Write OK "message of monitor.

  • Page 12: 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 IC901 PIN 6 TROUBLE IN WAVEFORM (SQUARE WAVE IC901 COMES OUT?) CHECK TROUBLE IN D941, D942, D951, D941, D942,D951,...
  • Page 13 2. NO IMAGE 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 14 3. NO RASTER NO VIDEO (POWER INDICATOR ON) CHECK AMBER DPM MODE POWER INDICATOR (NO H and/or V SYNC) GREEN or AMBER? GREEN CHECK TROUBLE IN D712 ANODE D712 (-160V)? CHECK TROUBLE IN G1 VOLTAGE? Q799 (-70V~ -90V) CHECK TROUBLE IN CDT HEAT VOLTAGE? D941, Q942, Q941...
  • Page 15 4. NO HORIZONTAL DEFLECTION NO H-DEFLECTION CHECK TROUBLE IN Q706? Q706 CHECK TROUBLE IN B + VOLTAGE 50V LINE (50V)? CHECK T701(FBT) PIN 2 TROUBLE IN (60~150V) ? Q719, Q720, IC701, D710 CHECK TROUBLE IN Q705 COLLECTOR Q705 WAVEFORM? TROUBLE IN T701, P701 - 15 -...
  • Page 16 5. TROUBLE IN H-LINEARITY UNBALANCED OF H-LIN. CHECK TROUBLE IN IC401 IC401 (MICOM) PIN 5, 6, 7 ? CHECK TROUBLE IN Q711~Q716? Q711 ~ Q716 CHECK TROUBLE IN L703? L703 Cs SIGNAL TABLE HORIZONTAL FREQUENCY(fH) 30K ~ 33.9K 34K ~ 38.9K TROUBLE IN 39K ~ 43.9K C722, C723, C726, C729...
  • Page 17 6. NO VERTICAL DEFLECTION NO V-DEFLECTION (ONE HORIZONTAL LINE) CHECK TROUBLE IN IC601 PIN 3 R603 (15V+)? CHECK TROUBLE IN IC701 PIN 12, 13? IC701 TROUBLE IN IC601, V-CIRCUIT - 17 -...
  • Page 18 7. 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 13 X401 WAVEFORM? 12MHz...
  • Page 19 8. NO DEGAUSSING NO DEGAUSSING (DEGAUSS ON THE OSD MENU MUST BE PRESSED.) CHECK TROUBLE IN IC401 PIN 1 IC401 (MICOM) (0V)? CHECK TROUBLE IN Q953 COLLECTOR Q953 (15V) VOLTAGE? DC 15V CHECK TROUBLE IN P902 ? P902 CHECK TROUBLE IN RL901? RL901 TROUBLE IN...
  • Page 20 9. NO TILT (NO ROTATION ) NO TILT (NO ROTATION) CHECK TROUBLE IN IC401 PIN21 IC401 ( MI COM) WAVE FORM ? CHECK TROUBLE IN 15V LINE 15V LINE, 6.3V LINE AND 6.3V LINE ? CHECK TROUBLE IN Q503 COLLECTOR Q501~Q503 VOLTAGE ? TROUBLE IN...
  • Page 21 - 21 -...

  • Page 22: Exploded View Parts List

    Ref. No. Part No. Description 3091TKC109A CABINET ASSEMBLY,HP V7550 H/PACKARD 3090TKC086 FCDT 6318L17012A CDT(CIRC), M41QEE903X 01N6UD LG-PHILIPS 85KHZ 29.1MM FLAT TCO 3809TKC056A BACK COVER ASSEMBLY, HP V7550 3808TKC050 FCDT 3043TKK093D TILT SWIVEL ASSEMBLY, CQ771H T062,B054 HF350U,CARBONITE 339-002K SCREW, TAPTITE P TYPE D5.0 L25.0 MSWR/FZMY .

  • Page 23: 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 :V7550 DATE:2003.10.09 MODEL :V7550 DATE:2003.10.09 LOC NO PART NO. DESCRIPTION/SPECIFICATON LOC NO PART NO.
  • Page 24 MODEL :V7550 DATE:2003.10.09 MODEL :V7550 DATE:2003.10.09 PART NO. DESCRIPTION/SPECIFICATON LOC NO PART NO. DESCRIPTION/SPECIFICATON LOC NO C754 0CC4700W405 47PF 500V J SL TP D315 0DS124409AA 1SS244 TP ROHM KOREA C767 0CK10301945 10000PF D 1KV Z F(Y5V) TR D402 0DS141489AB 1N4148 TP GRANDE DO-34 500MW 1 25NA(20V)
  • Page 25 MODEL :V7550 DATE:2003.10.09 MODEL :V7550 DATE:2003.10.09 PART NO. DESCRIPTION/SPECIFICATON PART NO. DESCRIPTION/SPECIFICATON LOC NO LOC NO COIL&CORE Q709 0TR141300AB KTD1413 BK KEC TO220I S NPN J311 6210TCE003A BRD3510B BO SUNG 3510MM RADIAL Q710 0TRKE90020A MPSA44 KEC TP TO92 500V 300MA...
  • Page 26 MODEL :V7550 DATE:2003.10.09 MODEL :V7550 DATE:2003.10.09 PART NO. DESCRIPTION/SPECIFICATON LOC NO PART NO. DESCRIPTION/SPECIFICATON LOC NO R408 0RD1300Q609 130 1/4W(3 5% TA52 R728 0RD1001Q609 1K 1/4W(3 5% TA52 R409 0RD1000Q609 100 1/4W(3 5% TA52 R729 0RD1002Q609 10K 1/4W(3 5% TA52...
  • Page 27 UL20276-9C(5.8MM) AT 1560MM COMPAQ R912 0RD1802Q609 18K 1/4W(3 5% TA52 BK CQ771H DM R913 0RD2201Q609 2.20K 1/4W(3 5% TA52 6318L17012A M41QEE903X 01N6UD LG-PHILIPS 85KHZ R915 0RD1200Q609 120 1/4W(3 5% TA52 29.1MM FLAT TCO R916 0RD1002Q609 10K 1/4W(3 5% TA52 6140TC3004B “75D-437 GET 0.4MM,120T,19...

  • Page 28: Pin Configuration

    PIN CONFIGURATION LM1246DDI 160 MHz I C RGB Video Amplifier System with OSD & DACs Internal Block Diagram Blue Green Analog Analog H Flyback Clamp DAC 1 DAC 2 DAC 3 DAC 4 Output Buffers DACs DC Offset RGB Gain Attenuation On Screen Display Switch: Video - OSD - 512 Byte RAM...
  • Page 29 TDA4867J PHILIPS 9P SYMBOL DESCRIPTION non-inverted input inverted input supply voltage OUTB output B OUTB ground TDA4867J OUTA output A OUTA flyback supply voltage V FB GUARD guard output GUARD FEEDB FEEDB feedback inprt Fig.2 Pin configuration. Pin Configuration Block Diagram GUARO output/ power save mode GUARD...
  • Page 30 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 Write Control SO8 (MN) 150mil Width Supply Voltage Logic Dirgram TSSOP8 (DW) Ground 169mil Width KA3842B Current-Mode PWM Controller BLOCK DIAGRAM SET/ RESET...
  • Page 31 TDA4841PS PHILIPS 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 33 Oct. 2003 P/NO : 3828TSO048E Printed in Korea...

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