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Website:http://biz.LGservice.com COLOR MONITOR SERVICE MANUAL CHASSIS NO. : LM76B MODEL: L1754SM (L1754SM-*FS.K****P* ) ) **Same model for Service CAUTION BEFORE SERVICING THE UNIT, READ THE SAFETY PRECAUTIONS IN THIS MANUAL.
PRECAUTION WARNING FOR THE SAFETY-RELATED COMPONENT. WARNING • There are some special components used in LCD BE CAREFUL ELECTRIC SHOCK ! monitor that are important for safety. These parts are • If you want to replace with the new backlight (CCFL) or marked on the schematic diagram and the inverter circuit, must disconnect the AC adapter...
SERVICING PRECAUTIONS 9. Use with this receiver only the test fixtures specified in CAUTION: Before servicing receivers covered by this 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.
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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.
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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"...
TIMING CHART VIDEO SYNC Total Video Sync Front Blanking Sync MODE H / V Frequency Duration Porch Time Period Active Resolution Polarity Clock ( E ) Time ( A ) ( D ) ( C ) ( B ) H(Pixels) 25.175 31.469 640 x 350...
DISASSEMBLY Put a cushion or soft cloth on a flat Place the monitor face down on surface. the cushion or soft cloth. Slide the Cable Deco Cover out from the stand body. Nip Latch inside, Take off the stand base from stand body. Please pull the stand body lightly Remove the screws.
DESCRIPTION OF BLOCK DIAGRAM 1. Video Controller Part. This part amplifies the level of video signal for the digital conversion and converts from the analog video signal to the digital video signal using a pixel clock. The pixel clock for each mode is generated by the PLL. The range of the pixel clock is from 25MHz to 135MHz.
LIPS Board Block Diagram 50 ~ 60Hz 100KHz HVDC SWITCHING INPUT RECTIFIER OUTPUT RECTIFIER TRANSFORMER COMPONENTS AND FILTER AND FILTER LINE 100 ~ 240V SIGNAL PWM CONTROL COLLENT- PHOTO-COUPLER CIRCUIT ISOLATION PRIMARY SECONDARY INVERTER CIRCUIT High Voltage Operation description_LIPS 1. EMI components. This part contains of EMI components to comply with global marketing EMI standards like FCC,VCCI CISPR, the circuit included a line-filter, across line capacitor and of course the primary protection fuse.
ADJUSTMENT Windows EDID V1.0 User Manual 2. EDID Read & Write 1) Run WinEDID.exe Operating System: MS Windows 98, 2000, XP Port Setup: Windows 98 => Don’t need setup Windows 2000, XP => Need to Port Setup. This program is available to LCD Monitor only. 1.
SERVICE OSD 1) Turn off the power switch at the front side of the display. 2) Wait for about 5 seconds and press MENU, POWER switch with 1 second interval. 3) The SVC OSD menu contains additional menus that the User OSD menu as described below. a) Auto Color : W/B balance and Automatically sets the gain and offset value.
TROUBLESHOOTING GUIDE 1. NO POWER NO POWER (POWER INDICATOR OFF) CHECK POWER BOARD, CHECK J703 AND FIND OUT A SHORT VOLTAGE POINT AS OPENING PIN5, PIN6 (5V)? EACH POWER LINE CHECK CHECK 3.3V LINE IC701 PIN2 VOLTAGE (OPEN CHECK) (3.3V) ? NO PROBLEM CHECK KEY CONTROL CONNECTOR ROUTINE...
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2. NO RASTER (OSD IS NOT DISPLAYED) – LIPS NO RASTER (OSD IS NOT DISPLAYED) CHECK POWER BOARD, J703 AND FIND OUT A SHORT PIN5, PIN6 POINT AS OPENING EACH POWER LINE CHECK MICOM INV J703 PIN9 ON/OFF PORT. 1. CONFIRM BRIGHTNESS OSD CONTRL STATE.
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3. NO RASTER (OSD IS NOT DISPLAYED) – MSTAR NO RASTER (OSD IS NOT DISPLAYED) IC501 CHECK IC701 PIN 16, 75 3.3V? IC501 1. CHECK C509, C511 SOLDERING CONDITION PIN96, 97 OSCILLATE AS 2. CHECK X501 3. TROUBLE IN IC501 14.31MHZ? IC501 PIN27 IS 48KHz H-SYNC?
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4. AUDIO NO Audio IC901 Check J703 Check Power PIN3 supply Assembly PIN 1,2 5V? 12V? Check IC 901 IC902 IC 902 Check J901 PIN14,17 PIN 4,9 input? output? Check IC 902 Check Speaker or earphone JACK - 18 -...
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5. TROUBLE IN DPM TROUBLE IN DPM CHECK PC CHECK PC IS NOT GOING R713, R714 INTO DPM OFF MODE CHECK IC501 PIN 27,28 CHECK H/V SYNC LINE SYNC PULSE ? TROUBLE IN IC501 Waveforms 3 V-Sync H-Sync - 19 -...
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6. POWER NO POWER (POWER INDICATOR OFF) CHECK Trouble in Fuse (F101) Fuse F101 OK? CHECK C101 Voltage Check D104,D105,D106,D107 (AC110V->160Vdc (AC220V->304Vdc CHECK Check U101 Pin7 : 9~10V U101 Pin6 Waveform Check D102 (Square wave Come out?) Check Q101 Drain Trouble in Q101 Waveform Check D201, D202...
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6. Raster NO Raster (Lamp Off) CHECK Check Scaler Output P201 Pin9 (Main Board) 3.3V? Check U301 Pin2 Check Q301, Q302 Check the waveform of U301 Check U301 Pin6 VSEN, Less than 3V Pin1, 15 Check the waveform of U301 Check U301 Pin12 SSTCMT, Pin2, 3 Less than 1V...