LG 901B Service Manual
  1. Manuals
  2. Brands
  3. LG Manuals
  4. Monitor
  5. 901B
  6. Service manual

LG 901B Service Manual

Color monitor
Hide thumbs
Table of Contents

Quick Links

COLOR MONITOR
SERVICE MANUAL
CHASSIS NO. : CA-123
FACTORY MODEL: CS992G
MODEL: 901B
CAUTION
BEFORE SERVICING THE UNIT,
READ THE SAFETY PRECAUTIONS IN THIS MANUAL.
MENU
(CS992G-EL)
SELECT
Table of Contents
loading

Related Manuals for LG 901B

Summary of Contents for LG 901B

  • Page 1 COLOR MONITOR SERVICE MANUAL CHASSIS NO. : CA-123 FACTORY MODEL: CS992G MODEL: 901B (CS992G-EL) CAUTION BEFORE SERVICING THE UNIT, READ THE SAFETY PRECAUTIONS IN THIS MANUAL. MENU SELECT...

  • Page 2: Table Of Contents

    CONTENTS SPECIFICATIONS ........... 2 DESCRIPTION OF BLOCK DIAGRAM....10 SAFETY PRECAUTIONS ........3 ADJUSTMENT ............12 TIMING CHART ............4 TROUBLESHOOTING GUIDE ......14 OPERATING INSTRUCTIONS ........ 5 EXPLODED VIEW..........21 CONTROL LOCATIONS ......... 6 REPLACEMENT PARTS LIST ......23 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 FACTORY PRESET MODE MODE MARK MODE 1 MODE 2 MODE 3 MODE 4 MODE 5 VESA Sync Polarity – Frequency 43.269 53.674 68.677 91.146 93.750 µs Total Period 23.112 18.631 14.561 10.971 10.666 µs Video Active Time 17.778 14.222 10.836...

  • Page 5: Operating Instructions

    OPERATING INSTRUCTIONS FRONT VIEW REAR VIEW ID Label MENU SELECT Power ON/OFF Button See Front Control Panel AC Power Socket Signal Connector Front Control Panel MENU SELECT Button 1. Power ON/OFF Button Use these buttons to choose or adjust items in the on Use this button to turn the monitor ON or OFF.

  • Page 6: Control Locations

    CONTROL LOCATIONS VR801 : High Voltage Adjustment (26kV) VR901: B Adjustment (190V Line) - 6 -...

  • Page 7: Wiring Diagram

    WIRING DIAGRAM Anode Cap DY-Pin DY Assembly Screw P801 P901 P201- P702 (Control PCB) P401 P451 P402 - 7 -...

  • Page 8: Disassembly

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

  • Page 9: Block Diagram

    SIGNAL INPUT...

  • Page 10: Description Of Block Diagram

    DESCRIPTION OF BLOCK DIAGRAM 1. Line Filter & Associated Circuit. 5. X-ray Protection. This is used for suppressing noise of power input line This circuit detects the rectified DC voltage comes flowing into the monitor and/or some noise generated from the FBT pin 4. If the high voltage of the FBT in this monitor flowing out through the power input reaches up to about 30kV (abnormal state), H.V control (IC802) detects.
  • Page 11 11. D/D Drive & Convert Circuit. 19. Image Rotation (Tilt) Circuit. This circuit is used for supplying B + voltage to This circuit corrects the tilt of the screen by supplying horizontal deflection output transistor (Q801). This the image rotation signal to the tilt coil which is circuit makes to add side-pincushion correcting signal attached to the CDT near the deflection.

  • Page 12: Adjustment

    ADJUSTMENT GENERAL INFORMATION 3) EEPROM → ALL CLEAR → Y(Yes) command. All adjustment are thoroughly checked and corrected Do not run this procedure unless the when the monitor leaves the factory, but sometimes EEPROM is changed. All data in EEPROM (mode several adjustments may be required.
  • Page 13 ± 0.1FL of 5. Input EDID Data. 11) Adjust SUB-Brightness command to 0.4 1) Display color 15,0 cross hatch pattern at Mode 4. the raster luminance. 2) EEPROM → Write EDID command and confirm 12) Display color 15,0 full white pattern at mode 4. 13) DRIVE ADJ command.

  • Page 14: Troubleshooting Guide

    TROUBLESHOOTING GUIDE 1. NO POWER NO POWER (POWER INDICATOR OFF) CHECK TROUBLE IN FUSE OK? FUSE (F901) CHECK TROUBLE IN D901 BRIDGE DIODE BRIDGE DIODE? (D901) CHECK C905(+) VOLTAGE TROUBLE IN 145VDC at 110V input IC901 310VDC at 220V input CHECK TROUBLE IN D924, D926, D923,...
  • Page 15 2. NO CHARACTER NO CHARACTER TROUBLE IN CHECK P301, SIGNAL CABLE, IC302 PIN 5, 6, 7 ? PC SIGNAL CHECK TROUBLE IN IC302 PIN 18, 19, 20, IC302, P302 PIN 9 (5V) ? CHECK TROUBLE IN IC303 PIN 1, 3, 5 PIN10 (12V), IC303 PIN 6 (80V) ?
  • Page 16 3. NO RASTER NO VIDEO (POWER INDICATOR GREEN or AMBER) CHECK AMBER TROUBLE IN POWER INDICATOR GREEN or AMBER ? P302 SIGNAL CABLE GREEN MIN. CHECK ROTATE SCREEN (Counter-clockwise) SCREEN CONTROL CONTROL KNOB TO KNOB OF FBT CLOCKWISE CHECK VOLTAGE AT D924/D926 CATHODE (190V) TROUBLE IN PRIMARY D923 CATHODE (80V)
  • Page 17 4. NO VERTICAL DEFLECTION NO V-DEFLECTION (ONE HORIZONTAL LINE) CHECK TROUBLE IN IC601 Pin 3 T901 PIN 18 (15V) ? CHECK TROUBLE IN IC601 PIN 7 T801 PIN 4, IC904 (47V)? CHECK TROUBLE IN IC801 PIN 13 IC801 (SAWTOOTH WAVE)? TROUBLE IN IC601, V-CIRCUIT - 17 -...
  • Page 18 5. TROUBLE IN DPM STAND-BY/SUSPEND/ OFF MODE FAILURE CHECK CHECK PC, IC401 (MICOM) NO H / V SYNC SIGNAL (PC IS NOT GOING INTO PIN 40, 41 (H/V INPUT) DPM MODE) SIGNAL? INPUT H/V SYNC CHECK TROUBLE IN IC401 PIN 9, 8 X401, IC401 WAVEFORM? CHECK...
  • Page 19 6. NO DEGAUSSING NO DEGAUSSING CHECK TROUBLE IN IC401 PIN 6 IC401 (MICOM) (5V)? CHECK TROUBLE IN Q920 COLLECTOR D925 VOLTAGE (0.5V)? CHECK TROUBLE IN P901? P901 TROUBLE IN CHECK RL901 RL901? TROUBLE IN TH901, DEGAUSSING COIL - 19 -...
  • Page 20 7. TROUBLE IN OSD NO OSD CHECK TROUBLE IN IC301 PIN 4 P302 (5V) ? CHECK IC301 PIN 5 TROUBLE IN (NEGATIVE H-PULSE P302 COMES IN ?) CHECK IC301 PIN 10 TROUBLE IN P302 (V-PULSE COMES IN?) CHECK IC301 PIN 13, 14, 15 TROUBLE IN (IS THERE ANY SIGNAL IC301, IC401...

  • Page 21: Exploded View

    EXPLODED VIEW...
  • Page 22 Ref. No. Part No. Description 3091TKC084A CABINET ASSEMBLY, CS992 BRAND TKC077 PC+ABS,85964,TCO99 2423GG2E92E CDT(CIRC), M46QCG913X 13NPUD LG-PHILIPS Displays 95KHZ 29.1 mm 3809TKC038C BACK COVER ASSY, CB997E TKC036 85964-PFC 3043TKK079A TILT SWIVEL ASSY, CB997E TKT054/TKB048 85964 339-002H SCREW ASSY, PHP+5*20(FZMY)+GW18 NEW TYPE 6140TC4002A COIL,DEGAUSSING, 1290MM 16.5OHM 0.45MM 115T 19"...

  • 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 DATE: 2002. 9. 12. DATE: 2002. 9. 12. *S *AL LOC. NO. PART NO. DESCRIPTION / SPECIFICATION *S *AL LOC.
  • Page 24 DATE: 2002. 9. 12. DATE: 2002. 9. 12. *S *AL LOC. NO. PART NO. DESCRIPTION / SPECIFICATION *S *AL LOC. NO. PART NO. DESCRIPTION / SPECIFICATION DIODEs C819 181-477U 333J 19.5*13.0*7.5*7.5 250V J C821 0CK1040K945 0.1UF 50V Z F TR D201 0DL305029BA LTL-305DJ-0C2 TP LITEON GREEN/...
  • Page 25 2N3904 TP SAMSUNG TO92 NPN Q724 0TR463300AB 2SC4633(LS-CB11) BK SANYO LS- COILs & COREs Q771 0TR920009AB KSP92 TP SAMSUNG TO92 HIGH VOL Q801 0TR558900BA 2SC5589(LG,W/M) BK TOSHIBA TO3 L304 0LA1000K119 100UH K 2.3*3.4 TP Q802 0TR471009AA KSD471AC-Y TP SAMSUNG TO92 NP - 25 -...
  • Page 26 DATE: 2002. 9. 12. DATE: 2002. 9. 12. *S *AL LOC. NO. PART NO. DESCRIPTION / SPECIFICATION *S *AL LOC. NO. PART NO. DESCRIPTION / SPECIFICATION Q803 0TR564009AB KSB564AC-YTA TP SANSUNG TO92 P R325 0RD1002Q609 10K 1/4W(3 5% TA52 Q806 0TR471009AA KSD471AC-Y TP SAMSUNG TO92 NP R326...
  • Page 27 DATE: 2002. 9. 12. DATE: 2002. 9. 12. *S *AL LOC. NO. PART NO. DESCRIPTION / SPECIFICATION *S *AL LOC. NO. PART NO. DESCRIPTION / SPECIFICATION R602 0RD1001Q609 1K 1/4W(3 5% TA52 R812 0RD2201Q609 2.20K 1/4W(3 5% TA52 R603 0RN0101H409 1.0 1/2W 1 TA52 R813 0RD2401Q609...
  • Page 28 DATE: 2002. 9. 12. *S *AL LOC. NO. PART NO. DESCRIPTION / SPECIFICATION R922 0RD5101Q609 5.10K 1/4W(3 5% TA52 R925 0RD1001Q609 1K 1/4W(3 5% TA52 R926 0RD4701Q609 4.70K 1/4W(3 5% TA52 R928 0RC0102J709 10 OHM 1 W 10% TA52 R941 0RD2703A609 270K OHM 1/2 W (7.0) 5% TA52 R942...

  • Page 29: Pin Configuration

    PIN CONFIGURATION TDA4866J Current Driven Vertical Deflection Booster SYMBOL OUTB TDA4866J OUTB OUTA V FB GUARD OUTA FEEDB GUARD FEEDB M62501P /FP Teerminal Number and The facillty PIN CONFIGURATION(TOP VIEW) PIN NO. Symbol Functional Description PWM output terminal PWM OUT Power supply terminal Trigger Input terminal PWM OUT...

  • Page 30: Schematic Diagram

    IIC-SDA IIC-SCL DDC-SDA DDC-SCL CS992G...
  • Page 31 1. CONTROL BOARD (Component Side) 2. CONTROL BOARD (Solder Side) 3. MAIN BOARD (Component Side) 4. MAIN BOARD (Solder Side)

This manual is also suitable for:

Cs992g-el

Table of Contents