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Website:http://biz.LGservice.com
E-mail:http://www.LGEservice.com/techsup.html
COLOR MONITOR
SERVICE MANUAL
CHASSIS NO. : CA-136
MODEL: T730BH(K) (T730BHKL-K***E*)
(T730SHKL-K***E*)
T730SH(K)
( ) **Same model for Service
CAUTION
BEFORE SERVICING THE UNIT,
READ THE SAFETY PRECAUTIONS IN THIS MANUAL.
*Same looking with new chassis.
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CONTENTS SPECIFICATIONS ................................................... 2 DESCRIPTION OF BLOCK DIAGRAM................... 11 SAFETY PRECAUTIONS ........................................ 3 ADJUSTMENT ....................................................... 13 SERVICE PRECAUTION.......................................... 4 TROUBLESHOOTING GUIDE .............................. 19 TIMING CHART ....................................................... 7 EXPLODED VIEW....................................
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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. parts list. It is essential that these critical parts should be The basic precaution which must be exer
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SERVICING PRECAUTIONS CAUTION: Before servicing receivers covered by this 9. Use with this receiver only the test fixtures specified in service manual and its supplements and addenda, read this service manual. and follow the SAFETY PRECAUTIONS on page 3 of this CAUTION: Do not connect the test fixture ground strap publication. to any heat sink in this receiver. NOTE: If unforeseen circumstances create conflict between the following servicing precautions and any of the Electrostatically Sensitive
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General Soldering Guidelines Replacement 1. Use a grounded-tip, low-wattage soldering iron and 1. Carefully insert the replacement IC in the circuit board. appropriate tip size and shape that will maintain tip 2. Carefully bend each IC lead against the circuit foil pad and solder it. temperature within the range or 500 F to 600 F. 3. Clean the soldered areas with a small wire-bristle 2. Use an appropriate gauge of RMA resin-core solder brush. (It is not necessary to reapply acrylic coating to co
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Circuit Board Foil Repair At Other Connections Excessive heat applied to the copper foil of any printed Use the following technique to repair the defective copper circuit board will weaken the adhesive that bonds the foil pattern at connections other than IC Pins. This technique to the circuit board causing the foil to separate from or involves the installation of a jumper wire on the "lift-off" the board. The following guidelines and component side of the circuit board. procedures should be fol
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TIMING CHART Video B C Sync D E F A << Dot Clock (MHz), Horizontal Frequency (kHz), Vertical Frequency (Hz), Horizontal etc... (µs), Vertical etc... (ms) >> Sync Video Time Front Porch Back Porch H/V Active Time Blanking Time Sync Time Mode Resolution Frequency (B) (D) (E) (F) Polarity (A) (C) Sort H - 37.50 26.67 20.32 6.35 0.51 2.03 3.81 640x480 1 - V 74.99 13.335 12.802 0.533 0.026 0.08 0.427 H + 46.88 21.33 16.16 5.17 0.32 3.223 1.62 2 800x600 V + 75.01 13.331 12.798 0.533 0.021 0.064 0.4
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C abinet B ac k C over DIS A S S E MB LY 1. T IL T /S WIV E L & B A C K C OV E R R E MOV A L 1) S et the monitor face downward. 2) C arefully remove the T ilt/S wivel by pulling it upward. 3) Remove the screw (b), Back cover by pushing it upward. 4) R elease the latch (c). (S ee T ip S pec.) 5) S lide the B ack C over away from the F ront C abinet of the monitor. (b) (c) (a) T ip S pec . A(Width) : 5.0~15.0mm C B (Depth) : 0.6~0.9mm Tip C (Height) : 12.0mm B A - 8 -
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WIRING DIAGRAM P220 P203 P201 P202 P405 P501 P904 P701 P702 + S S P402 T1 AC Socket P902 Signal Cable P302 P301 G2 - 9 - FBT
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BLOCK DIAGRAM Dynamic Focus Static Focus Screen 13V - 1 0 - H.V 5V 8V 80V BRIGHTNESS Heater ( 6.3V ) CONTR AST Video H-Sync MOIRE R Signal VIDEO DEGAUSSING V-Sync G VIDEO Pre-AMP / DY CDT H / V POSITION 2 Main AMP I C DATA(SD A) B OSD H / V SIZE (IC303) 2 I C CLOCK(SCL) (IC302) SPCC TR APEZOID G2 G1 PIN BAL ANCE PAR ALLELOGR AM 80V CUT OFF Circuit SCL / SDA ROTATION (Tilt) (IC304) RECALL / RESET H-Sync/V-Sync COLOR PWM Control Signal R/G/B INFORMATION Bias LANGU AGE OSD TIME TOP/BOTTOM CORNE
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DESCRIPTION OF BLOCK DIAGRAM 1. SMPS(Switching Mode Power Supply) 6. X-RAY Protection Circuit When you turn on the power switch, the operating When the high Voltage reaches to 29kV in an abnormal case, fprocedure is as follows: the high voltage detector circuit, R818,D721,C739-1 R416, C409 start operation to shut down high voltage circuit. 1) The AC line voltage is rectified by the bridge diode D900. 2) The control IC(IC901) starts switching and generates 7. Horizontal S-correction Circuit. sw
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15. Video Pre-Amp Circuit. 16. Video Output Amp Circuit. This circuit amplifies the analog video signal from 0~0.7 V This circuit amplifies the video signal which comes from the to 0~4 V. It is operated by taking the clamp, R,G,B drive video pre-amp circuit and amplified it to applied the CDT and contrast signal from the MICOM (IC401) cathode - 12 -
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ADJUSTMENT 1. Preparation for Service Adjustment 2. Adjustment by Service Hot key How to enter SVC HOT KEY GENERAL INFORMATION 1. Press Menu and OSD window will appear. 2. While OSD window is displayed, is seen on the All adjustment are thoroughly checked and corrected left bottom of OSD window. when the monitor leaves the factory, but sometimes 3. Press + power switch simultaneously and the several adjustments may be required. screen will immediately refresh. Adjustment should be following
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4. Distortion 10.Parallelogram Scanning frequency : All Mode (Mode 1~4) Display image : Crosshatch pattern Horizontal : 10 Row Vertical : 8 Row A B 4mm EG 11. Adjustment of white balance (Adjustment of chromaticity diagram) FH *(Adjustment of white balance must be made after C D entering Hot Key Mode and DEGAUSS.) A-B 2.0mm, C-D 2.0mm CONDITIONS E-F 2.0mm, G-H 2.0mm Signal: 69 kHz / 85 Hz Display image: Back raster (Color 0,0) Contrast: Maximum 5. Displa Size drift Brightness: Maximum 4mm : 25
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11-2. Adjustment of White Balance PROCEDURE After finishing adjustment of cut off (back raster), For trained and experienced service technicians only. approve "Color(15.0) Full white pattern". Use the following procedure to correct minor color Adjust BDRV Data = 85 purity problems: SCON=127. Adjust RDRV and GDRV to set chromaticity diagram at : 1. Make sure the display is not affected by external x: 0.283 0.005 magnetic fields. y: 0.298 0.005 Approve "Window pattern (70x70mm)" to a
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2. Adjustment for White Balance and Luminance. 3. Adjustment Using Service software Program (Adjustment Program) 1) Set the White Balance Meter. 2) Press the DEGAUSSING on the OSD menu for 1. Adjustment for Factory Mode (Preset Mode). demagnetization of the CDT. 3) Display color 0,0 pattern at Mode 4. 1) Display cross hatch pattern at Mode All. 4) COMMAND → PRESET START → Y(Yes) 2) Run alignment program for T730BHKL/T730SHKL command. on the IBM compatible PC. 5) Set Bightness and Contrast to ma
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4. EDID Data Edit Using Service software Program 4.1 Read and Modify EDID Data 1) Connector the monitor and adjust device as Figure1 2) Display color 15,0 cross hatch pattern at Mode 4. 3) Use EDIT – MODEL SEL. command to select the right model info file. 4) Use EDIT – EDID INFO command and return to read the EDID Data. 5) Modify the EDID Data if needed and using F10 to save the change and exit. 4.2 Write EDID Data. 1) Display color 15,0 cross hatch pattern at Mode 4. 2) Use EEPROM --
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220 VGS MONITOR F Fiig gu ur re e 1. 1. C Ca able ble C Co on nn nec ect tiio on n A IBM VIDEO 9 6 Compatible PC SIGNAL 5 1 15 11 GENERATOR 10 6 5 1 - 18 - C PARALLEL PORT 13 1 25 14 OFF ON 5V C F Power inlet (required) 5V Power Select Switch 4.7K (110V/220V) 4.7K ON 5V A Power LED E 74LS06 OFF 4.7K 74LS06 E ST Switch B B F V-Sync On/Off Switch (Switch must be ON.) - 18 - Not used PARALLEL RS232C V-SYNC ST POWER Control Line
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TROUBLESHOOTING GUIDE 1. NO POWER NO POWER (POWER INDICATOR OFF) TROUBLE NO CHECK IN FUSE (F901) FUSE OK?(F901) SMPS Switch (ON, OFF) YES CHECK NO TROUBLE IN D900 BRIDGE DIODE? BRIDGE DIODE (D900) YES CHECK C908(+) VOLTAGE NO TROUBLE IN 1 2 145VDC at 110V input IC901, Q901 310VDC at 220V input IC901, Q901 YES CHECK TROUBLE IN NO D971, D961, D951, D904 D971, D961, D951, D904 D941, D942, D906 ? D941, D942, D906 YES TROUBLE IN Q951, Q952, Q941, Q942, Waveforms 1 2 Q901, Drain IC901, #6 - 19 -
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2. NO CHARACTER NO CHARACTER TROUBLE IN NO CHECK 26 P301, SIGNAL CABLE, IC302 PIN 5,6,7 PC SIGNAL YES CHECK 27 28 NO TROUBLE IN IC302 PIN 1, 24, 23, 19, 20, 21 IC302, P301 29 30 PIN 18 (5V) ? YES CHECK NO IC303 PIN 1, 2, 3 TROUBLE IN PIN8 (8V), IC303 PIN 4 (80V) ? YES CHECK NO TROUBLE IN 31 R, G, B CATHODE IC304 VOLTAGE? YES TROUBLE IN CDT SOCKET Waveforms 26 27 28 IC302, #5, 6, 7 IC302, #1 IC302, #24 29 30 31 IC302, #23 IC302, #19, 20, 21 CDT, RK, GK, BK - 20 -
