Website:http://biz.LGservice.com COLOR MONITOR SERVICE MANUAL CHASSIS NO. : LM74B MODEL: L226WTQ(L226WTQ-BFS.A**MQP,A**QQP,A**VQP) L226WTQ(L226WTQ-WFS.A**OAP,A**QAP,A**VAP) ) **Same model for Service CAUTION BEFORE SERVICING THE UNIT, READ THE SAFETY PRECAUTIONS IN THIS MANUAL.
Page 3
Signal Connector Pin Assignment • DVI-D Connector (Digital) Signal (DVI-D) Signal (DVI-D) T. M. D. S. Data2- Hot Plug Detect T. M. D. S. Data0- T. M. D. S. Data2+ T. M. D. S. Data2/4 Shield T. M. D. S. Data0+ T.
PRECAUTION WARNING FOR THE SAFETY-RELATED COMPONENT. WARNING BE CAREFUL ELECTRIC SHOCK ! • There are some special components used in LCD 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 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.
Page 6
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.
Page 7
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 Resolution Period Active Polarity Clock ( E ) Time ( A ) ( D ) ( C ) ( B ) H(Pixels) 28.321 31.468 720 X 400...
DISASSEMBLY Remove the screws. Remove the screws. 1. Pull the front cover upward. 2. Then, let the all latches are separated with jig. (#3~4) 1.Disassemble PCB. Disassemble PCB. 2. Put the front face down. Disassemble back cover - 9 -...
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 146MHz In L226WTQ/WTG.
LIPS Board Block Diagram 50 ~ 60Hz 67KHz HVDC ENERGY INPUT RECTIFIER OUTPUT RECTIFIER TRANSFER COMPONENTS AND FILTER AND FILTER LINE 100 ~ 240V SIGNAL PHOTO- COLLENT- CONTROL COUPLER CIRCUIT ISOLATION PRIMARY SECONDARY Operation description_Power 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 => Doesn’t need setup Windows 2000, XP => Need to Port Setup. This program is available for LCD Monitor only. 1.
SERVICE OSD 1) Turn off the power switch at the right side of the display. 2) Wait for about 5 seconds and press MENU, POWER switch for 1 second interval. 3) The SVC OSD menu contains additional menus that the User OSD menu as described below. a) CLEAR ETI : To initialize using time.
TROUBLESHOOTING GUIDE 1. NO POWER NO POWER (POWER INDICATOR OFF) CHECK POWER BOARD, AND FIND OUT A SHORT CHECK J905 VOLTAGE POINT AS OPENING PIN5, PIN6 (5V)? EACH POWER LINE CHECK U901(3.3V) IS U901 PIN2(3.3V) U902(1.8V) LINE U902 PIN2(1.8V) CHECK X501 PIN127 CHECK CRYSTAL(X501) PULSE CHECK U501...
Page 16
2. NO RASTER (OSD IS NOT DISPLAYED) – LIPS NO RASTER (OSD IS NOT DISPLAYED) CHECK J905 CHECK POWER BOARD VOLTAGE PIN5,6 (LIPS) (5V)? CHECK U501 INVERTER J905 PIN9 3.3V? ON/OFF PORT 1. CONFIRM BRIGHTNESS OSD CONTRL STATUS CHECK J905 2.
Page 17
3. NO RASTER (OSD IS NOT DISPLAYED) - MAIN NO RASTER (OSD IS NOT DISPLAYED) CHECK U501 CHECK U901(3.3V), PIN114(3.3V) U902(1.8V) PIN21(1.8V) 1. CHECK PIN 127,128 U501 SOLDERING CONDITION PIN 127,128 2. CHECK X501 14.3MHZ? 3. TROUBLE IN U501 CHECK U501 PIN32(H-SYNC) AND CHECK CONNECTION LINE PIN33(V-SYNC).
Page 18
4. TROUBLE IN DPM TROUBLE IN DPM CHECK PC CHECK R718 AND PC IS GOING R719, SYNC INTO DPM MODE APPEARED? CHECK U501 PIN 32,33 CHECK H/V SYNC LINE SYNC PULSE TROUBLE IN U501 Waveforms 1 H-SYNC 2 V-SYNC - 18 -...