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Service Manual
XGA COLOR MONITOR
Model : 710B
DAEWOO ELECTRONICS CO., LTD
OVERSEAS SERVICE DEPT.
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CONTENTS SAFETY PRECAUTIONS 1 GENERAL SAFETY INFORMATION 2 SERVICING PRECAUTIONS 3 TECHNICAL INFORMATION 6 GENERAL INFORMATION 7 PIN CONNECTOR 8 CAUTIONS FOR ADJUSTMENT AND REPAIR 8 OPERATION & ADJUSTMENT 9 TROUBLESHOOTING HINTS 15 ALIGNMENT PROCEDURE 31 BLOCK DIAGRAM 33 PCB LAYOUT 34 SCHEMATIC DIAGRAM 37 EXPLODED VIEW DIAGRAM 38 REPLACEMENT PARTS LIST 39 CIRCUIT BOARD ELECTRICAL PARTS LIST 40
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SAFETY PRECAUTIONS CAUTION: No modifications of any circuit should be attempted. Service work should only be performed after you are thoroughly familiar with all of the following safety check and servicing guidelines. Safety Check Care should be taken while servicing this analog color display because of the high voltages used in the deflection circuits. These voltages are exposed in such areas as the associated flyback and yoke circuits. Fire & Shock Hazard • Insert an isolation transformer betw
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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 marking, or a hazard to properly including the equipment itself. WARNING Statements indicate a personal i
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SERVICING PRECAUTIONS CAUTION: Before servicing instruments covered by this service manual, its supplements and addendum, 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. General Servicing Precautions 1. Always unplug the AC power cord from the AC power source before: a. Removi
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Electrostatically Sensitive (ES) Devices Some semiconductor (solid state) devices can be damaged easily by static electricity. Such components commonly are called Electrostatically Sensitive (ES) Devices. The examples of typical 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. 1. Immediately before handling any semiconductor
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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. When working with boards using the familiar round hole, use the standard technique as outlined in paragraphs 5 on the page under the title of general soldering guidelines. Removal 1. Desolder
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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. Solder each device lead, and clip off excess lead. 6. Replace heatsink. Diode Removal/Replacement 1. Remove defective diode by clipping its leads as close as possible to diode body. 2. Bend the two remaining leads perpendicularly to the circu
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GENERAL INFORMATION This color monitor automatically scans all horizontal frequencies from 30KHz to 69KHz, and all vertical frequencies from 50Hz to 160Hz. This color monitor adopted the OSD (On Screen Display), it shows the sync polarity and frequency and it provides that easily adjust control. 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 :
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PIN CONNECTOR Pin Signal 1 Red 1 2 Green 3 Blue 4 GND 610 5 GND 6 GND - Red 7 GND - Green 15 8 GND - Blue 9 Reserved Arrangement of 15-pin D-sub connector 10 GND - H.Sync 11 GND 12 Bi-directional Data (SDA) 13 Horizontal Sync 14 Vertical Sync (VCLK) 15 Data Clock (SCL) CAUTIONS FOR ADJUSTMENT AND REPAIR • Degaussing is always required when adjusting purity or convergence. • The white balance adjustment has been done by a color analyzer in factory. The adjustment procedure, described in the servi
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OPERATION & ADJUSTMENT ADJUSTMENT KEY Launch OSD(On-Screen Display) menus Select the next function Increase the value of any selected function Decrease the value of any selected function 9
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ADJUSTMENT PROCESS R G B R G B BRIGHTNESS CONTRAST 50% 50% R G B R G B PINCUSHION TRAPEZOID 50% 50% R G B R G B K K COLOR TEMP. RED GAIN 9300 6550 50% R G B R G B Z Z Z Z Z Z RECALL STATUS H : +31.5KHZ NO YES V : +70.5 HZ When you choose the icon on the OSD window, you can exit the OSD screen. 10
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OSD(On-Screen Display) Menu 1 Adjust the contrast of image, the difference between light and dark CONTRAST areas on the screen. 50% Range : 0-100% BRIGHTNESS Adjust the brightness of the entire display. 50% Adjust the position of the display horizontally H.POSITION (left or right). 50% H.SIZE Adjust the display width (horizontal size). 50% V.POSITION Adjust the position of the display vertically (up or down). 50% V.SIZE Adjust the display height (vertical size). 50% Degauss the display and rest
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OSD(On-Screen Display) Menu 2 Adjust the left and right margins for more convex or more concave margins. • Image turns to by . - • Image turns to by . Adjust the trapezoid of the screen by moving the lines inward or outward. TRAPEZOID • Image turns to by . 50% - • Image turns to by . Adjust parallelogram when the screen is leaning left or right. PARALLELOGRAM • Image turns to by . 50% - • Image turns to by . Adjust the side balance when the sides of the screen are bowed towards left or right. PI
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OSD(On-Screen Display) Menu 3 Choose different preset color temperatures or set your own customized color parameters. RED GAIN Adjust the red gain. 50% GREEN GAIN Adjust the green gain. 50% BLUE GAIN Adjust the blue gain. 50% RED BIAS Adjust the red bias. 50% GREEN BIAS Adjust the green bias. 50% BLUE BIAS Adjust the blue bias. 50% OSD(On-Screen Display) Menu 4 STATUS Display horizontal & vertical frequency and polarity. H : +31.5KHZ V : +70.5 HZ Reset the screen to the Factory Preset Displ
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Self Diagnosis When the monitor doesn’t display, if you press any key, Self Diagnosis screen is displayed. Self Diagnosis function checks if the status of the monitor is No Signal or Out of range. No Signal screen is displayed when the D-Sub signal connector is not connected or the status of the monitor is on DPMS mode. Out of Range screen is displayed when the applied frequency is under or over normal range. Normal range H : 30-69 KHz V : 50-160 Hz 14
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TROUBLESHOOTING HINTS 1. No Character No Character Are the Change the Contrast & No Contrast & Brightness control to Brightness Controls maximum maximum Yes Is whole No Refer to No Raster screen bright? No Raster Yes Is CRT Yes Cathode (Rk, Gk, Bk) Check the peripheral circuit signal level of CRT Board normal? Rk, Gk, Bk About 45Vpp No Is the output signal of the Check the video output Yes (pin 21, 24, 26) pre-amp circuit and IC803 (pin 1, 3, 5) (IC801, KA2500) and their ambient circuit normal?
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2. No Raster No Raster Is Heater Is CRT No No Trouble in Voltage (CRT PWB) heater red-hot? CRT about 6V? Yes Yes Turn the Brightness Trouble in Refer to trouble in & Contrast control power supply power supply unit. to set Maximum circuit Yes Is whole No Trouble in power screen bright? supply circuit Yes Check No Trouble in G1 G1 voltage about line of Main PWB -40V? Yes Is CRT No G2 (screen) voltage Trouble in FBT about 500V? Yes Trouble in 80/ Is 80V DC Refer to trouble No 120V DC line of line n
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3. A missing Color One color is missing No Is input signal Check video signal normal? cable or video card. 0.7Vpp Yes Is the output of pre-amp No Trouble in IC801 or its (IC801, KA2500) ambient circuit pin 21, 24, 26 all normal? Yes CRT Is video Trouble in No No Cathode (Rk, Gk, Bk) output IC803 waveform video output is normal? normal? RK, GK, BK circuit, IC803 About 40V p-p or ambient Yes Yes Trouble in 80/120V DC Each grid (G1, G2) line voltage normal? Yes No Trouble in 80/120V DC Replace CRT
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4. Abnormal OSD Font Abnormal OSD Font * If menu key selected. Is menu Is Heater Trouble in No No key selected? Voltage (CRT PWB) Heater voltage Is OSD Font about 6V? line. exist? Refer to trouble in P.S.U Yes Yes One color is Troubie in missing IC802 or its ambient circuit Yes Is the Trouble in IC802 No output of IC802 and its ambient (pin 13, 14, 15) circuit normal? Yes Refer to Missing Color 18
