COLOR MONITOR SERVICE MANUAL
Contents
1. 2 4 2 A508 gt EE gt 10K lt U W 21 A510 NE 0 p P518 470 100 2 7 eO INVON 4 470 2 9 9 1 5 5 1 2 Ay b 3 3vD 4 2 2 9 c512 a3 10uF 16V X501 al 0D mal ID 9 1 5 5 1 a 14 318MHz iat C IC QU m p npn B H 9 x a n Qo wo DO Se O as lt vimlalalolals o Hino Kolko R524 gt oln au 3 3v RL 4 2 1 1 oo 1 VDVI 2 3o ie TT OHIO DI ZI HAI HIZ Ha Aya gt d C527 523 525 gt alo oiir Ti tur 4uF Qjoj jxo xjojolalojoj oloo0 m a do m o 20 2 C511 I L DDCL SCI 1 BYPASS ortum 2 GND2 5 GND79 1 3 LVBOM 2 gt YOM B 4 2 4 LVBOP 2 gt YOP B 4 2 GND5 5 GND76 Gt VDDP75 21 6 6 7 LVB1 2 gt Y 1M B 4 2 AVDD_DVI8 gt 8 gt Y1P 8 1 2 1 LVB2 gt Y2N B 4 2 gt 5 gt 52. ao qus VA emm gm Copyright G 2007 LG Electronics Inc All right reserved Only for training and service purposes 27 LGE Internal Use Only 4 POWER ZEN x TOT ANN e sc BUCH HH gt Je zes i er AO gt 102 Allo o n Y mr I e e AD LGE Internal Use Only 2007 LG Electronics Inc All right reserved 28 Only for training and service purposes JUN 2008 P NO MFL40349711 Printed in China
3. AC220V gt 304Vdc CHECK U101 Pin6 Waveform Check U101 Pin7 9 10V Square wave Check D102 Come out Check Q101 Drain Trouble in Q101 Waveform Check D201 D202 Trouble in D201 D202 D203 D203 Voltage CHECK 5V 15V Line Copyright c 2007 LG Electronics Inc All right reserved LGE Internal Use Only Only for training and service purposes 20 6 Raster NO Raster Lamp Off CHECK Check Scaler Output P201 Pin9 3 3 Board Check 0301 Pin2 Check Q301 Q302 5V Check U301 Pin6 VSEN Check the waveform of U301 Less than 3V Pini 15 Check U301 12 SSTCM sire the waveform of U301 Less than 1V In2 3 If waveform is no problem Check U 303 U304 Check D302 D308 Drain waveform Or Trouble U 303 0304 CHECK T301 2007 LG Electronics Inc All right reserved Only for training and service purposes LGE Internal Use Only WIRING DIAGRAM n 30P EAD37413101 EAD42157802 663190001 1J Copyright C 2007 LG Electronics Inc All right reserved LGE Internal Use Only Only for training and service purposes 22 EXPLODED VIEW IMPORTANT SAFETY NOTICE Many electrical and mechanical parts in this chassis have special safety related characteristics These parts are identified by Nin the Schematic Diagram and EXPLODED VIEW It is essential that these special safety parts should be replaced
4. Make certain that treatment person s body are grounded through wrist band Do not leave the module in high temperature and in areas of high humidity for a long time The module not be exposed to the direct sunlight Avoid contact with water as it may a short circuit within the module f the surface of panel become dirty please wipe it off with a softmaterial Cleaning with a dirty or rough cloth may damage the panel N CAUTION Please use only a plastic screwdriver to protect yourself from shock hazard during service operation 2007 LG Electronics Inc All right reserved EN Only for training and service purposes WARNING BE CAREFUL ELECTRIC SHOCK f you want to replace with the new backlight CCFL or inverter circuit must disconnect the AC adapter because high voltage appears at inverter circuit about 650Vrms e Handle with care wires or connectors of the inverter circuit If the wires are pressed cause short and may burn or take fire Leakage Current Hot Check Circuit AC Volt meter Good Earth Ground such as WATER PIPE To Instrument s CONDUIT etc exposed METALLIC PARTS 1 5 Kohm 10W LGE Internal Use Only SERVICING PRECAUTIONS CAUTION Before servicing receivers covered by this service manual and its supplements and addenda read and follow the SAFETY PRECAUTIONS on page 3 of this publication NOTE If unforeseen circumstances create co
5. a Xu SANL Jo e s 8 9 u lt BR ES 727 Jayng JVO9XIA S L DN qn s q LGE Internal Use Only 10 2007 LG Electronics Inc All right reserved Only for training and service purposes BLOCK DIAGRAM POWER yoeqpaa uano 49 14 eur dwe7 yoeqpeeJ l JO1U0D Suel 3 16 18MOd xny ASL O 01991044 jo31u05 1 430 90 1 gt J9 e2S 99A dH3 ld3ANI d3MOd LGE Internal Use Only 243 2007 LG Electronics Inc All right reserved Only for training and service purposes 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 15 25MHz to 135MHz This part consists of the Scaler ADC convertor TMDS receiver and LVDS transmitter The Scaler gets the video signal converted analog to digital interpolates input to 1280 X 1024 resolution signal and outputs 8 bitR G B signal to transmitter 2 Power Part This part consists of the one 3 3V and one 1 8V regulators to convert power
6. L1942P Width 406 3 16 00 Depth 241 6 mm 9 51 Height 422 7 mm 16 64 532 7 mm 20 97 8 WEIGHT with TILT SWIVEL Horizontal 30 83kHz L1742P Vertical 56 75Hz Net Weight 3 83 kg 8 51 16 Gross Weight 5 37 kg 11 93lbs L1942P Net Weight 4 23 kg 9 40 Ibs Gross Weight 5 94 kg 13 20165 2007 LG Electronics Inc All right reserved Only for training and service purposes LGE Internal Use Only PRECAUTION WARNING FOR THE SAFETY RELATED COMPONENT There are some special components used in LCD monitor that are important for safety These parts are marked on the schematic diagram and the hi parts list t is essential that these critical parts should be replaced with the manufacturer s Specified parts to prevent electric shock fire or other hazard Do not modify original design without obtaining written permission from manufacturer or you will void the original parts and labor guarantee TAKE CARE DURING HANDLING THE LCD MODULE WITH BACKLIGHT UNIT e Must mount the module using mounting holes arranged in four corners Do not press on the panel edge of the frame strongly or electric shock as this will result in damage to the screen Do not scratch or press on the panel with any sharp objects such as pencil or pen as this may result in damage to the panel Protect the module from the ESD as it may damage the electronic circuit C MOS
7. Only for training and service purposes 2 EDID Read amp Write 1 Run WinEDID exe 14 gt WinEDID MIEQe ooo ooo S Ies CON IH Ou 00 0050 0070 2 Edit Week of Manufacture Y ear of Manufacture Serial Number a Input User Info Data b Click Update button C Click Write button LGE Internal Use Only 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 b NVRAM INIT EEPROM initialize 24C08 CLEAR To initialize using time d AGING Select Aging mode on off e R G B 9300K Allows you to set the R G B 9300K value manually f R G B 6500K Allows you to set the R G B 6500K value manually g R G B Offset Allows you to set the R G B Offset value manually Analog Only h R G B Gain Allows you to set the R G B Gain value manually Analog Only i MODULE To select applied module IBM Video Signal Compatible PC Generator Power inlet required Contro Line Power Select Switch 110V 220V F V Sync On Off Switch Swit
8. components The following techniques should be used to help reduce the incidence of component damage caused by static by static electricity 1 Immediately before handling any semiconductor component or semiconductor equipped assembly drain off any electrostatic charge on your body by touching a known earth ground Alternatively obtain and wear a commercially available discharging wrist strap device which should be removed to prevent potential shock reasons prior to applying power to the unit under test 2 After removing an electrical assembly equipped with ES devices place the assembly on a conductive surface such as aluminum foil to prevent electrostatic charge buildup or exposure of the assembly 3 Use only a grounded tip soldering iron to solder or unsolder ES devices 4 Use only an anti static type solder removal device Some solder removal devices not classified as anti static can generate electrical charges sufficient to damage ES devices 5 Do not use freon propelled chemicals These can generate electrical charges sufficient to damage ES devices 6 Do not remove a replacement ES device from its protective package until immediately before you are ready to install it Most replacement ES devices are packaged with leads electrically shorted together by conductive foam aluminum foil or comparable conductive material 7 Immediately before removing the protective material from the leads of a replacement ES device tou
9. 12 2 R521 O O OJO lt 33 al gt aja HIN gt 2 UJ ajla aya T NIN oa 4 4 slo afa ao d O H an ap n d n alo lt 3 3v nm 1 2 T e SST25VFO20 204C SAE 13 3VD 4 2 2 CSZ 11 4 2 500 c 13 3V PL 4 2 1 SCK 4 7K R517 C515 0 0 0 4 7K R519 1uF ON vo 5 on K 00 0 0 a 8 am ek 0 a LGE Internal Use Only 25 2007 LG Electronics Inc All right reserved Only for training and service purposes 2 POWER amp WAFER H606 0601 7701 AC 1117S33T IN OUT KCN DS 3 0062 07 1 ad 0713 ao vc e B 4 A x im x D ND E m m n zz C594 ame 95 E E 100uF Y a a 1 Us02 LD11178418TR 0 RED A 4 2 R732
10. original leads If they are not shiny reheat them and if necessary apply additional solder Fuse and Conventional Resistor Removal Replacement 1 Clip each fuse or resistor lead at top of the circuit board hollow stake 2 Securely crimp the leads of replacement component around notch at stake top 3 Solder the connections CAUTION Maintain original spacing between the replaced component and adjacent components and the circuit board to prevent excessive component temperatures LGE Internal Use Only Circuit Board Foil Repair Excessive heat applied to the copper foil of any printed circuit board will weaken the adhesive that bonds the foil to the circuit board causing the foil to separate from or lift off the board The following guidelines and procedures should be followed whenever this condition 15 encountered Connections To repair a defective copper pattern at IC connections use the following procedure to install a jumper wire on the copper pattern side of the circuit board Use this technique only on IC connections 1 Carefully remove the damaged copper pattern with a sharp knife Remove only as much copper as absolutely necessary 2 carefully scratch away the solder resist and acrylic coating if used from the end of the remaining copper pattern 3 Bend a small U in one end of a small gauge jumper wire and carefully crimp it around the IC pin Solder the IC connection 4 Route the jumper wir
11. pIMADJ 4 2 10 TSUMUSBBWH LVBeP c vep B e GND1 1 LVBCKM SCALER PWM DIMMING gt CLKOUTM B 4 2 2 LVBCKP SSS SS SS 2 1 gt CLKOUTP B 4 2 CK 3 LVB3 gt Y3M B 4 2 AVDD DVI14 4 LVB3P 1 C Y3P B 4 2 VDDC56 2 5 ee AVDD_P 6 LVAO R504 7 J X YOMCA 2 2 LIPS PWM DIMMING 150 c5Qg 0 04742 BINO 7 LVAOP 9 B C YOP A 4 2 pw 5 1 2 A502 56 C5030 047uF BINOP 8 LVA1 A526 ANY 9 2 gt 1 4 2 22 1 5K 8503 C504 0 o47uF GINO 9 LVA1P 4 7K ppt ion READY oC 4 Y1P A 4 2 A504 56 C5050 047uF GINOP LVA2 1 90 biwvAD 1 2 2 gt 9 20 C Y2M A 4 2 1505 1K ceog 1000pF SOGINO LVA2P 9 C Y2P A 1 2 G 8505 C507 0 047uF RINOM LVACKM 9 4 7 G502 11 BEING C CLKOUTM A 4 2 LAMPADJ DIM KST3904 R507 O47uF L tion READY a 507 56 CS0F 047u T opt ion READY 00201 AVDD ADC GND57 4 7 Q501 LAME KsT3904 0 0 00 0 0 UU Eum E VDDP56 Fo tur REFP LVA3 gt 1 1 9 HSYNCO LVA3P 3 3V PL 1 TES C Y3P A 4 C520 VSYNCO MODE 1 Fo 4uF 2 9 M24C16 WMNGT GND29 ODE O A AS232_TX VDDC51 in 92109 E A520 33 SCLK 9 lt uo lt 94 0 SDATACG 2
12. D SDAA 4 2 9 gt GRN A 4 2 4 2730 9 gt HSYNC 4 2 7 50 gt BLU A 4 2 x gt DDC5V 2731 le F ww 0 7 gt VSYNC 4 2 ppt fon ZQ708 5e NL R728 9 D SCLA 4 2 R729 o pe ST DET 4 2 L e m ao 4 o o D O jn 0 D 4 O iD go ve 50 DS QTR QR N FA nu QT L n m MIR IC ee ete Met lo opt ion SPEAKER BAR MODEL d db e cake 1 Ag L d 4 705 KJA DC 3 0002 N C710 0 4uF 5 5 1 2 5 5 4 2 712 4 R701 C713 0 1UF C744 0 tuF 4 Doi Qo Op C715 0 152 l g opftson reAby Z as Qi A E Qi 4 2 AR x SS f K AO C7164 0 f P ey re 09 52 ao C718 0 1uF ost ion A fov MBD30 1L T4 M3 ppcsv a Y 78 Y 1 5 7 gt 2 44 I __ LIESS Ya 4 UB04 7 0701 J706 gt M24CO2 AMNET ee GH11121 DNO D CJ Savin Byes YS 9213 H HX2 1 2 8 EEPROM 4 2 8214 Rx2 9215 1D SCLA 4 2 We RX1 2 12 ID SDAA 4 2 NT 4 2 1 RXO NT 4 2 RXOT 05 5VHPD Bz24 D715 At 9 ID SCLB 4 2 OO MMBD30 1LT 4 Pe 0pcs5vD 25 1 9 4 999 9 A2 84 30V Cc 3 5VS 4 2 958 ugo3 M2AC
13. LG Website http biz LGservice com COLOR MONITOR CHASSIS NO LM72A MODEL FLATRONL1742P L1742P FT A QPN FLATRONL1942P L1942P FT A QPN Same model for Service CAUTION BEFORE SERVICING THE UNIT READ THE SAFETY PRECAUTIONS IN THIS MANUAL NOT MENU AUTOSET JENGINE VOLUME et sss apply the MSTAR Chip CONTENTS SPECIFICATIONS ai a eTa 2 SERVICE a i 17 PREGAUTIONS E EE E ncs 3 TROUBLESHOOTING GUIDE 18 7 WIRING DIAGRAM 24 DISASSEMBLY 0 00 0 00 8 BLOCK DIAGRAM MEC en DISCRIPTION OF BLOCK DIAGRAN 14 REPLACEMENT PARTS LIST 27 ADJUSTMENT SED 16 SCHEMATIC DIAGRAM mmm 32 SPECIFICATIONS 1 LCD CHARACTERISTICS Type TFT Color LCD Module Active Display Area 17 inch L1742P 19 inch L1942P Pixel Pitch 0 264 H x 0 264 V L1742P 0 294 H x 0 294 V L1942P Color Depth 8bits 16 7M colors Size 358 5 H x 296 5 V x 16 0 D L1742P 396 H x 324 V x 15 5 D L1942P Electrical Interface LVDS Surface Treatment Operating Mode Backlight Unit Hard coating 3H Anti Glare Normally White Transmissive mode 4 CCFL 2 OPTICAL CHARACTERISTICS 2 1 Viewing Angle by C
14. O2 BRMNGT 8219 axl flex RXC 4 2 NS 20 RXC 1 2 9 4 2 276 eO 15VHPD C 3D SCLB 1 2 DDC5VD gt 1D SDAB 4 2 c709 77 lt x Z0 iUF mu om F m om 1 No 7 N optiqn 3 3V PL 4 2 3 3VD 4 2 dio 5V MOD 1 8VD 4 2 CLKOUT CLKOUTM A Y2P A Y2M A Y1P A 1 YOM A Y3P B Y3M B CLKOUTP B CLKOUTM B J703 SMW200 11 YeP B Y2M B YAP B Y41M B YOP B YOM B gt 12VS SCALER PWM gt SVS 1 2 1000hm LIPS PWM CONTROL 2 1 INVON 4 2 lt gt DIMADU 4 2 5 w M So 400 ol 0 9 C706 0 1uF le 100pF J704 SMW200 O6 SCALER PWM 100pF 11 PS PWM 1uF LAMPADJ 4 2 5 5 4 2 Q701 KST3906 MTF 706 R707 C KEYO 4 1 C703 1 1 O4uUF 7 C702 O1uF 6 6 6 6 C KEY 4 2 Q702 2 A711 OS ee 1 KST3906 MTE uis E R710 ey 4 4 7K 4 13 3VD 4 2 el 2 2 LGE Internal Use Only 26 2007 LG Electronics Inc All right reserved Only for training and service purposes gt j lt 9 3 INVERTER I e
15. Wes We _ IL NNNM We WP E HEX E RE EL NN We Wes _ We _ Heres 9 os 78 75 37 879 60 317 46 875 NW E NN SN RN NM Om NN 74 7455 667 EE E EN mes w 68 681 75 062 ms opo ae EL NN E NN 8 2007 LG Electronics Inc All right reserved Only for training and service purposes 1066 79 976 1688 15035 1066 Blanking LGE Internal Use Only DISASSEMBLY Set 1 Soft pad the table Place the monitor face down on the cushion or soft cloth 3 1 Remove the 4 serews 2 Disassembly Stand 4 1 Pull the front cover upward Disassemble back cove 2 Then let the all latches are separated 3 Put the front face down 2007 LG Electronics Inc All right reserved LGE Internal Use Only Only for training and service purposes DISASSEMBLY Stand Push the two latches on the bottom to the inside Reference the 1 2 2 Separate stand body form the stand base 2007 LG Electronics Inc All right reserved LGE Internal Use Only Only for training and service purposes BLOCK DIAGRAM LUS SAS 125 vads JOVIQSW Sduue 7 JOUSAU me NJ lt JoyeinDa ABE WOY ysel 4 20819941
16. and solder it 3 Clean the soldered areas with a small wire bristle brush It is not necessary to reapply acrylic coating to the areas Small Signal Discrete Transistor Removal Replacement 1 Remove the defective transistor by clipping its leads as close as possible to the component body 2 Bend into a U shape the end of each of three leads remaining on the circuit board 3 Bend into a U shape the replacement transistor leads 4 Connect the replacement transistor leads to the corresponding leads extending from the circuit board and crimp the U with long nose pliers to insure metal to metal contact then solder each connection Power Output Transistor Device Removal Replacement 1 Heat and remove all solder from around the transistor leads 2 Remove the heat sink mounting screw if so equipped 3 Carefully remove the transistor from the heat sink of the circuit board 4 Insert new transistor in the circuit board 5 Solder each transistor lead and clip off excess lead 6 Replace heat sink Diode Removal Replacement 1 Remove defective diode by clipping its leads as close as possible to diode body 2 Bend the two remaining leads perpendicular y to the circuit board 3 Observing diode polarity wrap each lead of the new diode around the corresponding lead on the circuit board 4 Securely crimp each connection and solder it 5 Inspect on the circuit board copper side the solder joints of the two
17. ch must be ON Figure 1 Cable Connection 2007 LG Electronics Inc All right reserved 15 LGE Internal Use Only Only for training and service purposes TROUBLESHOOTING GUIDE 1 NO POWER NO POWER POWER INDICATOR OFF Check Power Board Check 703 Voltage And Find Out a Short Point 5 Pin6 5V as Opening Each Power Line a Check U601 Pin2 Voltage 3 3V Check 3 3V Line Open Check No Problem Check Key Control Connector Routine Is U201 Pin75 3 3V Check 3 3V Line Voltage Check U201 Pin 96 Check X TAL Pulse Check U501 11 U201 496 Tak 25 065 iT ors T iin a be 11 21 18 2007 LG Electronics Inc All right reserved Only for training and service purposes LGE Internal Use Only 16 2 NO RASTER OSD IS NOT DISPLAYED LIPS NO RASTER OSD IS NOT DISPLAYED CHECK POWER BOARD AND FIND OUT A SHORT POINT AS OPENING EACH POWER LINE 703 PIN5 PIN6 5V CHECK MICOM INV ON OFF PORT 1 CONFIRM BRIGHTNESS 703 PIN10 OSD CONTRL STATE 5 2 CHECK DIM ADJ PORT CHECK PULSE AS CONTACTING SCOPE PROBE TO CAUTION LABEL CONTACT PROBE TO CAUTION LABEL CAN YOU SEE PULSE AT YOUR SCOPE REPLACE CCFL LAMP IN THE LCD MODULE 2007 LG Electronics Inc All right reserved LGE Internal Use O
18. ch the protective material to the chassis or circuit assembly into which the device will be installed CAUTION Be sure no power is applied to the chassis or circuit and observe all other safety precautions 8 Minimize bodily motions when handling unpackaged replacement ES devices Otherwise harmless motion such as the brushing together of your clothes fabric or the lifting of your foot from a carpeted floor can generate static electricity sufficient to damage an ES device LGE Internal Use Only General Soldering Guidelines 1 Use a grounded tip low wattage soldering iron and appropriate tip size and shape that will maintain tip temperature within the range or 500 F to 600 F 2 Use an appropriate gauge of RMA resin core solder composed of 60 parts tin 40 parts lead 3 Keep the soldering iron tip clean and well tinned 4 Thoroughly clean the surfaces to be soldered Use a mall wire bristle 0 5 inch or 1 25cm brush with a metal handle Do not use freon propelled spray on cleaners 5 Use the following unsoldering technique a Allow the soldering iron tip to reach normal temperature 500 F to 600 F b Heat the component lead until the solder melts c Quickly draw the melted solder with an anti static suction type solder removal device or with solder braid CAUTION Work quickly to avoid overheating the circuitboard printed foil 6 Use the following soldering technique a Allow the soldering iron tip to reac
19. d 0 6mm n MDQ42883001 Lamp shield PRESS SBHG 0 6mm 1 1942 SBHG L1942 Lamp shield 0 6mm 420 MDQ41956328 Rear shield 11742 11942 rear shield dual with forming without spring 510 EAY41830902 AIP 0172 FREE W1942S T LCD Lienchang LIEN CHANG CO LTD 520 EBR36999511 MAIN T T LM72A BAIKAL Il MSTAR DUAL RD BT AAN52377605 STAND L1742P LM57D STAND BODY ASSY 110mm Height Stand NEC Module 52377601 Stand Body Assembly BASE L1942P Wx42P LM57D STAND BODY ASSY 110mm Height Stand 920 52427401 Stand Base Assembly BASE L1942P Wx42P LM57D STAND BASE ASSY 110mm Height Stand 930 MEG42848901 Holder MOLD NYLON 66 CABLE Cable Holder 940 MFG34448601 Locker PRESS STEEL STS pi 1 5 ACCESORY NON NON new height stand PIN FIX Copyright 2007 LG Electronics Inc All right reserved Only for training and service purposes LGE Internal Use Onl x e SCHEMATIC DIAGRAM 1 SCALER 1 ST DET 1 DDET 1 SHORT CHK 1 D SDAB 1 D SCLB 1 2 1 2 1 RX4 1 1 1 VDVI 1 1 1 RXC 1 3 4 BLU A 1 GRN A 1 RED A 4 HSYNC 4 VSYNC 1 D SDAA 1 D SCLA 1 MODON 1 2 2
20. e along the path of the out away copper pattern and let it overlap the previously scraped end of the good copper pattern Solder the overlapped area and clip off any excess jumper wire 2007 LG Electronics Inc All right reserved Only for training and service purposes At Other Connections Use the following technique to repair the defective copper pattern at connections other than IC Pins This technique involves the installation of a jumper wire on the component side of the circuit board 1 Remove the defective copper pattern with a sharp knife Remove at least 1 4 inch of copper to ensure that a hazardous condition will not exist if the jumper wire opens 2 Trace along the copper pattern from both sides of the pattern break and locate the nearest component that is directly connected to the affected copper pattern 3 Connect insulated 20 gauge jumper wire from the lead of the nearest component on one side of the pattern break to the lead of the nearest component on the other side Carefully crimp and solder the connections CAUTION Be sure the insulated jumper wire is dressed so the it does not touch components or sharp edges LGE Internal Use Only Sync aie 25 175 TIMING CHART Total Frequency Bi hs 49 m 31 468 70 08 Video Front Sync Active ice Time EN NEN IN EN NE SN BN W WEE W We
21. h a normal temperature 500 F to 600 F b First hold the soldering iron tip and solder the strand against the component lead until the solder melts Quickly move the soldering iron tip to the junction of the component lead and the printed circuit foil and hold it there only until the solder flows onto and around both the component lead and the foil CAUTION Work quickly to avoid overheating the circuit board printed foil d Closely inspect the solder area and remove any excess or splashed solder with a small wire bristle brush IC Remove Replacement Some chassis circuit boards have slotted holes oblong through which the IC leads are inserted and then bent flat against the circuit foil When holes are the slotted type 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 and 6 above Removal 1 Desolder and straighten each IC lead in one operation by gently prying up on the lead with the soldering iron tip as the solder melts 2 Draw away the melted solder with an anti static suction type solder removal device or with solder braid before removing the IC 2007 LG Electronics Inc All right reserved Only for training and service purposes Replacement 1 Carefully insert the replacement IC in the circuit board 2 Carefully bend each IC lead against the circuit foil pad
22. nergy to secondary through a power transformer 4 Output rectifier and filter This part function is to make a pulse width modulation control and to provide the driver signal to power switch to adjust the duty cycle during different AC input and output loading condition to achieve the dc output stabilized and also the over power protection is also monitor by this part 5 Photo Coupler isolation This part function is to feed back the DC output changing status through a photo transistor to primary controller to achieve the stabilized DC output voltage 6 Signal collection This part function is to collect the any change from the DC output and feed back to the primary through photo transistor 2007 LG Electronics Inc All right reserved 13 LGE Internal Use Only Only for training and service purposes ADJ USTMENT Windows EDID V1 0 User Manual Operating System MS Windows 98 2000 XP Port Setup Windows 98 gt Don t need setup Windows 2000 XP gt Need to Port Setup This program is available to LCD Monitor only 1 Port Setup Copy UserPort sys file to C WINNT system32 drivers folder b Run Userport exe c Remove all default number d Add 300 3FF UserPort Tomas Franzon 2000 l IHHETTIGVE sa Remove e Click Start button f Click Exit button 2007 LG Electronics Inc All right reserved
23. nflict between the following servicing precautions and any of the safety precautions on page 3 of this publication always follow the safety precautions Remember Safety First General Servicing Precautions 1 Always unplug the receiver AC power cord from the AC power source before a Removing or reinstalling any component circuit board module or any other receiver assembly b Disconnecting or reconnecting any receiver electrical plug or other electrical connection c Connecting a test substitute in parallel with an electrolytic capacitor in the receiver CAUTION A wrong part substitution or incorrect polarity installation of electrolytic capacitors may result in an explosion hazard d Discharging the picture tube anode 2 Test high voltage only by measuring it with an appropriate high voltage meter or other voltage measuring device DVM FETVOM etc equipped with a Suitable high voltage probe Do not test high voltage by drawing an arc 3 Discharge the picture tube anode only by a first connecting one end of an insulated clip lead to the degaussing or kine aquadag grounding system shield at the point where the picture tube socket ground lead is connected and then b touch the other end of the insulated clip lead to the picture tube anode button using an insulating handle to avoid personal contact with high voltage 4 Do not spray chemicals on or near this receiver or any of its assemblies 5 Unless specified othe
24. nly Only for training and service purposes E ird 3 NO RASTER OSD IS NOT DISPLAYED MSTAR NO RASTER OSD IS NOT DISPLAYED U201 PIN 16 75 3 3V S CHECK U601 a U201 1 CHECK C509 C510 PIN96 97 SOLDERING CONDITION OSCILLATE AS 2 CHECK X501 14 31MHZ 3 TROUBLE IN U201 U201 PIN27 IS 48KHz H SYNC CHECK CONNECTION PIN28 IS 60Hz V SYNC LINE FROM D SUB TO IS PULSE APPEARED U201 AT SIGNAL PINS AT MODE 12 YES TROUBLE IN CABLE OR LCD MODULE 11 U201 96 97 2 U201 428 V SYNC 5 00 5 144 Ac mE TAC 1 30 4 1 56 1 Tek 25 005 T 975 j N j 4 i rec 14 28775MH2 ow amplitude ten TAB ii 2004 02 90 2007 LG Electronics Inc All right reserved Only for training and service purposes 18 LGE Internal Use Only 4 TROUBLE IN DPM TROUBLE IN DPM CHECK R730 R731 CHECK PC PC IS NOT GOING INTO DPM OFF MODE CHECK U201 PIN 27 28 CHECK H V SYNC LINE SYNC PULSE TROUBLE IN 0501 R731V Sync 2007 LG Electronics Inc All right reserved Only for training and service purposes 19 LGE Internal Use Only 5 POWER NO POWER POWER INDICATOR OFF CHECK Fuse F101 OK Trouble in Fuse F101 C101 Voltage AC110V gt 160Vdc Check D104 D105 D106 D107
25. ontrast Ratio gt 10 Left 60 min 70 Typ Right 60 min 70 Typ Top 60 min 75 Typ Bottom 50 min 65 Typ 2 2 Luminance 230 min 300 Full White pattern 0 70V 6500K 150 min Full White pattern 0 70V 9300K 75 min 2 3 Contrast Ratio 8000 1 DFC 3 SIGNAL Refer to the Timing Chart 3 1 Sync Signal Separate Sync Digital SOG 3 2 Video Input Signal 1 Type Analog 2 Voltage Level 0 0 71 V a Color 0 0 0 Vp p b Color 7 0 0 467Vp p C Color 15 0 0 714 Vp p Input Impedance 75Q 3 3 Operating Frequency 4 Max Resolution D sub Analog Digital 1280 x 1024 p75Hz 1280 x 1024 60Hz 5 POWER SUPPLY 5 1 Power AC 100 240V 50 60Hz 0 6A 5 2 Power Consumption H V SYNC VIDEO POWER CONSUMPTION LED COLOR less than 30 W L1742P BLUE POWER ON NORMAL ON ON ACTIVE less than 34 W L1942P or Flicker STAND BY OFFION OFF less than 1W Flicker SUSPEND ON OFF less than 1W Flicker DPMS OFF OFF OFF OFF less than 1 W Flicker POWER S W Off less than 1 OFF 6 ENVIRONMENT 6 1 Operating Temperature 10 C 35 C 50 F 95 F Ambient 6 2 Relative Humidity 10 80 Non condensing 6 3 MTBF 50 000 HRS with 90 Confidence Lamp Life 50 000 Hours Min 7 DIMENSIONS with TILT SWIVEL L1742P Width 369 6 mm 14 55 Depth 241 6 mm 9 51 Height 408 3 mm 16 07 518 3 mm 20 41
26. rwise in this service manual clean electrical contacts only by applying the following mixture to the contacts with a pipe cleaner cotton tipped stick or comparable non abrasive applicator 10 by volume Acetone and 90 by volume isopropyl alcohol 90 99 strength CAUTION This is a flammable mixture Unless specified otherwise in this service manual lubrication of contacts in not required 6 Do not defeat any plug socket B voltage interlocks with which receivers covered by this service manual might be equipped 7 Do not apply AC power to this instrument and or any of its electrical assemblies unless all solid state device heat sinks are correctly installed 8 Always connect the test receiver ground lead to the receiver chassis ground before connecting the test receiver positive lead Always remove the test receiver ground lead last 2007 LG Electronics Inc All right reserved Only for training and service purposes 9 Use with this receiver only the test fixtures specified in this service manual CAUTION Do not connect the test fixture ground strap to any heat sink in this receiver 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 Examples of typical ES devices are integrated circuits and some field effect transistors and semiconductor chip
27. which Is provided 5V in Power board 12V is provided for inverter 5V is provided for LCD panel Also 5V is converted 3 3V and 1 8V by regulator Converted power is provided for IC in the main board The inverter converts from DC12V to AC 700Vrms and operates back light lamps of module 3 MICOM Part This part is include video controller part And this part consists of EEPROM IC which stores control data Reset IC and the Micom The Micom distinguishes polarity and frequency of the H V sync are supplied from signal cable The controlled data of each modes is stored in EEPROM 2007 LG Electronics Inc All right reserved Only for training and service purposes 19 LGE Internal Use Only LIPS Board Block Diagram EMI INPUT RECTIFIER SWITCHING 100E OUTPUT RECTIFIER m COMPONENTS AND FILTER TRANSFORMER AND FILTER 100 240V SIGNAL PWM CONTROL 4 PHOTO COUPLER COLLENT SEIT ISOLATION ION PRIMARY SECONDARY 12V 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 2 Input rectifier and filter This part function is for transfer the input AC voltage to a DC voltage through a bridge rectifier and a bulk capacitor 3 Energy Transfer This part function is for transfer the primary e
28. with the same components as recommended in this manual to prevent X RADIATION Shock Fire or other Hazards Do not modify the original design without permission of manufacturer Copyright C 2007 LG Electronics Inc All right reserved Only for training and service purposes LGE Internal Use Only Nc EXPLODED VIEW PARTS LIST z Part No Description SVA170SX01TB DRIVER 17INCH 1280X1024 300CD COLOR 72 4 3 700 1 NEC CORPORATION 206 LM170E03 TLG1 17 0INCH 1280X1024 300CD COLOR 72 4 3 1000 1 P5 Gumi ZBD EAJ44187001 5ms 170 H 160 V TLI T con Lusem Source GIP Gate Diffuser 1 Prism 1 6304 LM190E08 TLG1 SXGA 19 0INCH 1280X1024 300CD COLOR 72 4 3 1000 1 P4 Gumi ZBD Sms 170 H 160 V TLI T con Lusem Source GIP Gate Diffuser 1 Prism MBH42876401 MOLD HIPS L1742 HIPS L1742 Cabinet 300 MBH42876201 MOLD HIPS L1942 HIPS L1942 Cabinet 310 MEY42882101 Control button MOLD ABS HF 350 MAIN 5 Lx42 Lx42 BLACK 320 MFB42881801 Led Lens MOLD PC LG LENS Lx42 Lx42 Lens 330 EBR37001507 CONTROL T T LM72A BAIKAL 19 INCH BLUE RD 42 SERIAL MCK42876810 Back cover MOLD HIPS LPL DUAL TILT 9 42876501 Back cover MOLD HIPS LPL DUAL TILT MDQ42883102 Lamp shield PRESS SBHG 0 6mm 1 1742 SBHG 11742 Lamp shiel
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