Daewoo 712B Service Manual
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Daewoo 712B Service Manual

Daewoo 712B Service Manual

Xga color monitor
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Service Manual
XGA COLOR MONITOR
Model : 712B
DAEWOO ELECTRONICS CO., LTD
OVERSEAS SERVICE DEPT.

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Summary of Contents for Daewoo 712B

  • Page 1 Service Manual XGA COLOR MONITOR Model : 712B DAEWOO ELECTRONICS CO., LTD OVERSEAS SERVICE DEPT.

  • Page 2: Table Of Contents

    CONTENTS SAFETY PRECAUTIONS GENERAL SAFETY INFORMATION SERVICING PRECAUTIONS TECHNICAL INFORMATION GENERAL INFORMATION PIN CONNECTOR CAUTIONS FOR ADJUSTMENT AND REPAIR OPERATION AND ADJUSTMENT ALIGNMENT PROCEDURE TROUBLESHOOTING HINTS BLOCK DIAGRAM PCB LAYOUT SCHEMATIC DIAGRAM EXPLODED VIEW & MECHANICAL PARTS LIST INFORMATION OF PART DESCRIPTION ELECTRICAL PARTS LIST...

  • Page 3: Safety Precautions

    X-Ray, shock, fire or other hazards. Do not modify the original design without getting written permission from DAEWOO ELECTRONICS CO. or this will void the original parts and labor warranty.

  • Page 4: General Safety Information

    GENERAL SAFETY INFORMATION Terms in the manual CAUTION Statements identify conditions or practices that could result in damage to the equipment or other property. WARNING Statements identify conditions or practices that could result in personal injury or loss of life. Terms as marked on equipment CAUTION Statements indicate a personal injury hazard not immediately accessible as one reads the...

  • Page 5: Servicing Precautions

    SERVICING PRECAUTIONS CAUTION: Before servicing instruments covered by this service manual, its supplements, and addendum, please read and follow the SAFETY PRECAUTIONS of this manual. NOTE: If unforeseen circumstances create conflict between the following servicing precautions and any of the safety precautions on page 1 of this manual, always follow the safety precautions. Remember: Safety First.
  • Page 6 Electrostatically Sensitive (ES) Devices Some semiconductor (solid state) devices can be damaged easily by static electricity. Such components are commonly called Electrostatically Sensitive (ES) Devices. The typical examples of ES devices are integrated circuits, some field-effect transistors, and semiconductor “chip” components. The following techniques should be used to help reduce the incidence of component damage caused by static electricity.
  • Page 7 FIGURE 1. USE SOLDERING IRON TO PRY LEADS IC Removal/Replacement Some utilized chassis circuit boards have slotted (oblong) holes through which the IC leads are inserted and then bent flat against the circuit foil. When holes are slotted, the following technique should be used to remove and replace the IC.

  • Page 8: Technical Information

    Power IC, Transistor or Devices Removal/Replacement 1. Heat and remove all solders from the device leads. 2. Remove the heatsink mounting screw (if applicable). 3. Carefully remove the device from the circuit board. 4. Insert new device in circuit board. 5.

  • Page 9: General Information

    GENERAL INFORMATION This color monitor automatically scans all horizontal frequencies from 30KHz to 70KHz, and all vertical frequencies from 50Hz to 160Hz. This color monitor supports IBM PC, PC/XT, PC/AT, personal System/2 (PS/2), Apple Macintosh, and compatible users crisp text and vivid color graphics display when using the following graphics adapters : (VGA, 8514/A, Super VGA, VESA and XGA and Apple Macintosh Video Card).

  • Page 10: Pin Connector

    PIN CONNECTOR Signal Green Blue GND - Red GND - Green GND - Blue +5Vdc Arrangement of 15-pin D-sub connector GND - H.Sync GND - V.Sync Bi-directional Data (SDA) Horizontal Sync Vertical Sync (VCLK) Data Clock (SCL) CAUTIONS FOR ADJUSTMENT AND REPAIR •...

  • Page 11: Operation And Adjustment

    OPERATION AND ADJUSTMENT Control Panel • Move cursor to the right window on the OSD window. • Increase the value of any selected function. • Move cursor to the left window on the OSD window. • Decrease the value of any selected function. •...

  • Page 12: Hot Key

    Key Process MENU Start • When you choose the icon on the OSD window, you can exit the OSD screen. Hot Key BRIGHTNESS CONTRAST...

  • Page 13: Osd Functions

    OSD Functions ICON CONTROL FUNCTIONS Adjust the left and right margins for more convex or more concave margins. PINCUSHION Adjust the trapezoid of the screen by moving the lines inward or outward. TRAPEZOID PIN BALANCE Adjust the side balance when the sides of the screen are bowed towards left or right. Adjust the parallelogram when the screen is leaning left or right.
  • Page 14 ICON CONTROL FUNCTIONS Adjust the horizontal picture moire cancellation. H. MOIRE Adjust the vertical picture moire cancellation. V. MOIRE Select language for OSD (5 languages). LANGUAGE Reset the screen to the Factory Preset Display Settings. RECALL...

  • Page 15: Alignment Procedure

    ALIGNMENT PROCEDURE Standard Adjustment Conditions 1. Power source voltage : AC 120V, 60Hz/AC 220V, 50Hz. 2. Aging : Take at least 20 minutes warm-up time. 3. Signals. Video : Analog 0.7Vpp 75Ω terminal positive polarity Synchronizing : TTL Level Negative/Positive Separate/Composite Deflection frequency Horizontal Frequency : 30KHz - 70KHz Vertical Frequency : 50Hz - 160Hz...
  • Page 16 (f) Set the brightness control to the center and contrast control to the maximum. (g) Receive a full white pattern. (h) Select the R, G, B gain on the OSD menu and adjust the ADJUST +/– key to get the color coordinates in X=0.281±0.02, Y=0.311±0.02.

  • Page 17: Troubleshooting Hints

    TROUBLESHOOTING HINTS 1. No Character No Character Are the Change the Contrast & Contrast & Brightness control to Brightness Controls maximum maximum Is whole Refer to No Raster screen bright? No Raster Is CRT Check the peripheral circuit Cathode (Rk, Gk, Bk) of CRT Board signal level Rk, Gk, Bk...
  • Page 18 2. No Raster No Raster Is Heater Is CRT Trouble in Voltage (CRT PWB) heater red-hot? about 6V? Turn the Brightness Trouble in Refer to trouble in & Contrast control power supply power supply unit. circuit to set Maximum Is whole Trouble in power screen bright? supply circuit...
  • Page 19 3. A Missing Color One color is missing Is input signal Check video signal normal? cable or video card. 0.7Vpp Is the output of pre-amp Trouble in IC801 or its (IC801, KA2500) ambient circuit pin 21, 24, 26 all normal? Is video Trouble in Cathode (Rk, Gk, Bk)
  • Page 20 4. Abnormal OSD Font Abnormal OSD Font * If menu key selected. Is menu Is Heater Trouble in key selected? Voltage (CRT PWB) Heater voltage Is OSD Font about 6V? line. exist? Refer to trouble in P.S.U One color is Troubie in missing IC204or its...
  • Page 21 5. Horizontal Output Circuit Trouble in Horizontal output circuit (No Raster Trouble in B+ Booster Circuit Is the (Check the B+section of IC501, B+line voltage Check Q546 and its ambient over 180V? circuit). Is the H-out waveform of IC501 Trouble in IC501 normal? Is the Collector wave form of...
  • Page 22 6. Unstable Picture 6-1. Horizontal Unstable picture Is H.Sync Check H.Sync Out of input pin of IC501 Micom or its ambient correct? circuits. Is the Check the value of pin 1 of IC501 C514, R516 Trouble in IC501...
  • Page 23 6-2. Vertical Unstable or Abnormal picture Check PWR ± 13V ± 13V DC line ambient circuit. correct? the output 45Vp-p Check V.DY waveform of IC401 and ambient circuit. (pin 6) normal? Is the output pulse Check the IC401 of IC501 (pin 23) or ambient circuit.
  • Page 24 7. Focus Monitor remains unfocused Check Focus VR in focus acceptable? Trouble in Focus circuit (FBT)

  • Page 25: Dynamic Focus

    7-1. Dynamic Focus * Check after adjusting the static focus Focus is poor ORION : 300V 120V finely by VR in FBT SAMSUNG : 300V 120V waveform Is the 1. Check the CRT socket waveform of the or connector wire DF pin in FBT 2.
  • Page 26 8. Convergence Poor convergence convergence Adjust static on the center area convergence bad? Refer to Adjustment procedure of convergence Adjust D.Y convergence on the Location fringe area bad?
  • Page 27 9. Abnormal Picture 9-1. Horizontal Size Abnormal H.Size When Check pin 15 of IC501 the VR501 is and its ambient circuit changed, is the H.size (D547, R552, R553, C553) changed? Is the 1.Check B+ section of TDA9111 H.Size overscan at 60KHz and its ambient circuit.
  • Page 28 9-2. Vertical Size Abnormal V.Size Check the IC401 changeable the the 3.5Vdc of pin and its DC voltage of 23 of the IC501? IC401 pin 1? ambient circuit Trouble V.OSC/ Check the IC501 and Deflection Circuit its ambient circuit Refer to V.OSC/Deflection circuit...
  • Page 29 10. High Voltage Output Circuit Trouble in H.V circuit (No Raster) Trouble in power B+(120V) line supply circuit voltage normal? Is Q608 Trouble in Q608 or FBT base waveform normal? Is Q601 Trouble in Q601, Q605 collector waveform 12V Line normal? Is IC601 pin 10...
  • Page 30 11. Side-Pincushion Circuit Side-Pincusion distortion is excessive or barrel Select the side-pincushion icon on OSD menu, and adjust acceptable position. Check IC501 or Is the pin 24 their ambient circuit waveform of IC501 (pin 14, 15, 16) correct Is the Check IC501 or waveform of IC501 it's ambient circuit.
  • Page 31 12. Power Supply Unit (P.S.U) Trouble in P.S.U power switch Switch on Check the power cord outlet fuse F001 and diode D001, D002, O.K? D003, D004 Trouble in D001, D002, voltage of T001 D003, D004, C004 and pin 9 130V TH001.
  • Page 32 Is voltage Trouble in D108, IC102 or of C114 13Vdc? horizontal Part. Trouble in D103 or vertical voltage of C121 Part. -13Vdc? Is voltage of C107 Trouble in D104 6.3Vdc? P.S.U O.K...

  • Page 33: Block Diagram

    BLOCK DIAGRAM...

  • Page 34: Pcb Layout

    PCB LAYOUT Main PCB Component Side...
  • Page 35 Main PCB Solder Side...
  • Page 36 CRT PCB Component Side...
  • Page 37 CRT PCB Solder Side...

  • Page 38: Schematic Diagram

    SCHEMATIC DIAGRAM Power Section...
  • Page 39 Micro-controller/OSD/Vertical Section...
  • Page 40 Horizontal Section-A...
  • Page 41 Horizontal Section-B...
  • Page 42 Video Section...

  • Page 43: Exploded View & Mechanical Parts List

    EXPLODED VIEW & MECHANICAL PARTS LIST...

  • Page 44: Information Of Part Description

    INFORMATION OF PART DESCRIPTION Important Safety Notice Components identified with the International Symbol have special characteristics important for safety. When replacing any components, use only manufacturer’s specified parts. Abbreviation of Description RESISTOR Description Allowance ± 1% ± 5% ± 10% ±...

  • Page 45: Electrical Parts List

    ELECTRICAL PARTS LIST ! have special characteristics important for safety and x-ray radiation. The components identified by mark These should be replaced only with the types specified in the parts list. PART-CODE PART-NAME PART-DESC PART-CODE PART-NAME PART-DESC 00001 9979800488 PCB MAIN T1.6*330*246 C209 HCQK220JCA C CHIP CERA 50V CH 22PF J 2012...
  • Page 46 PART-CODE PART-NAME PART-DESC PART-CODE PART-NAME PART-DESC C542 CMXL2A104J C MYLAR MEU 100V 0.1MF J C821 HCFK104ZCA C CHIP CERA 50V Y5V 0.1MF Z 2012 C544 CEXF2A220V C ELECTRO 100V RSS 22MF (8*11.5) TP C823 HCFK104ZCA C CHIP CERA 50V Y5V 0.1MF Z 2012 C545 CMXL2A104J C MYLAR MEU 100V 0.1MF J C825 HCFK104ZCA C CHIP CERA...
  • Page 47 PART-CODE PART-NAME PART-DESC PART-CODE PART-NAME PART-DESC D201 DZN4148--- DIODE 1N4148 AUTO 52MM IC102 1KA78R12-- IC REGULATOR KA78R12 D202 DZN4148--- DIODE 1N4148 AUTO 52MM IC103 1K1A7805P1 IC REGULATOR KIA7805API D301 DRP1H----- DIODE RP1H IC201 1DWM250--- IC MICOM ST7275 D302 DRP1H----- DIODE RP1H IC202 124C08---- IC EEPROM...
  • Page 48 PART-CODE PART-NAME PART-DESC PART-CODE PART-NAME PART-DESC Q544 TKSD471ACY TR KSD471ACY R218 RD-AZ472J- R CARBON FILM 1/6 4.7K OHM J Q545 TKSA539CY- TR KSA539CY R219 HRFT203JCA R CHIP 1/10 20K OHM J 2012 Q546 T2SJ449--- 2SJ449 R220 RD-AZ102J- R CARBON FILM 1/6 1K OHM J Q547 TBU4525AX- TR BU4525AX...
  • Page 49 PART-CODE PART-NAME PART-DESC PART-CODE PART-NAME PART-DESC R501 RD-AZ361J- R CARBON FILM 1/6 360 OHM J R582 HRFT562JCA R CHIP 1/10 5.6K OHM J 2012 R504 HRFT824JCA R CHIP 1/10 820K OHM J 2012 R583 RD-4Z101J- R CARBON FILM 1/4 100 OHM J R507 HRFT473JCA R CHIP 1/10 47K OHM J 2012 R585 RD-4Z473J-...
  • Page 50 SW276 5S50101Z01 SW TACT KPT-1115VM 1C-1P R843 RD-4Z910J- R CARBON FILM 1/4 91 OHM J T001 5RM0000093 TRANS SMPS DMT-712B R845 RD-4Z910J- R CARBON FILM 1/4 91 OHM J T002 5RY0000002 TRANS SYNC DST-603 R851 RC-2Z470J- R CARBON COMP 1/2 47 OHM J...
  • Page 51 DAEWOO ELECTRONICS CO., LTD 686, AHYEON-DONG MAPOGU, SEOUL, KOREA. C.P.O. BOX 8003 SEOUL KOREA TELEX: DWELEC K28177-8 CABLE: "DAEWOOELEC" FAX: 02) 590-6291 TEL: 02) 360-7114/590-6151~5 http://www.dwe.daewoo.co.kr PRINTED DATE: SEPT.1999...

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