LG 26LH20 Series, Service Manual

Page 1: ...E SERVICING THE CHASSIS READ THE SAFETY PRECAUTIONS IN THIS MANUAL CHASSIS LA92A MODEL 42LH30 42LH30 UA North Latin America http aic lgservice com Europe Africa http eic lgservice com Asia Oceania http biz lgservice com Internal Use Only ...

Page 2: ...nics Inc All right reserved Only for training and service purposes LGE Internal Use Only CONTENTS CONTENTS 2 PRODUCT SAFETY 3 SPECIFICATION 6 ADJUSTMENT INSTRUCTION 9 TROUBLE SHOOTING 14 BLOCK DIAGRAM 20 EXPLODED VIEW 21 SVC SHEET ...

Page 3: ...o operate without damage of electrical shock Leakage Current Cold Check Antenna Cold Check With the instrument AC plug removed from AC source connect an electrical jumper across the two AC plug prongs Place the AC switch in the on position connect one lead of ohm meter to the AC plug prongs tied together and touch other ohm meter lead in turn to each exposed metallic parts such as antenna terminal...

Page 4: ... 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...

Page 5: ... the solder joints of the two 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 repla...

Page 6: ...1 Application Range This specification sheet is applied to the LCD TV used LA92A chassis 2 Specification Each part is tested as below without special appointment 1 Temperature 25 5 C 77 9ºF CST 40 5ºC 2 Relative Humidity 65 10 3 Power Voltage Standard input voltage 100 240V 50 60Hz Standard Voltage of each products is marked by models 4 Specification and performance of each parts are followed each...

Page 7: ... 015 for Adjustment Medium 0 283 0 285 0 287 0 291 0 293 0 295 Warm 0 311 0 313 0 315 0 327 0 329 0 331 6 Component Video Input Y CB PB CR PR No Specification Remark Resolution H freq kHz V freq Hz Pixel clock 1 720 480 15 73 60 13 5135 SDTV DVD 480I 2 720 480 15 73 59 94 13 5 SDTV DVD 480I 3 720 480 31 50 60 27 027 SDTV 480P 4 720 480 31 47 59 94 27 0 SDTV 480P 5 1280 720 45 00 60 00 74 25 HDTV 7...

Page 8: ...Remark PC DDC 1 640 350 31 469 70 08 25 17 EGA X 2 720 400 31 469 70 08 28 32 DOS O 3 640 480 31 469 59 94 25 17 VESA VGA O 4 720 400 37 879 60 31 40 00 VESA SVGA O 5 1024 768 48 363 60 00 65 00 VESA XGA O 6 1280 768 47 776 59 87 79 50 CVT WXGA O 7 1360 768 47 720 59 799 84 75 CVT WXGA O DTV 1 720 480 31 5 60 27 027 SDTV 480P 2 720 480 31 47 59 94 27 00 SDTV 480P 3 1280 720 45 00 60 00 74 25 HDTV ...

Page 9: ...ID DDC download White Balance adjustment RS 232C functionality check Factory Option setting per destination Ship out mode setting In Stop 3 3 Etc Ship out mode Service Option Default USB Download S W Update Option Service only ISP Download Option 4 Automatic Adjustment 4 1 ADC Adjustment 1 Overview ADC adjustment is needed to find the optimum black level and gain in Analog to Digital device and to...

Page 10: ... Change input mode as RGB and picture mode as Standard 4 Press the In start Key on the ADJ remote after at least 1 min of signal reception Then select 7 External ADC 1 COMP 480i on the menu Press enter key The adjustment will start automatically 5 If ADC calibration is successful ADC RGB Success is displayed If ADC calibration is failure ADC RGB Fail is displayed 6 If ADC calibration is failure af...

Page 11: ... 58 2C 40 45 00 7E 8A 42 00 00 1E 01 1D 00 72 51 D0 1E 20 50 6E 28 55 00 7E 8A 42 00 00 1E 00 00 00 FD 00 39 60 3F 1F 52 10 00 0A 20 20 20 20 20 20 00 00 00 FC 70 00 4C 47 20 54 56 0A 20 20 20 20 20 20 20 01 XX 0 1 2 3 4 5 6 7 8 9 A B C D E F 0 02 03 1F F1 47 90 22 20 05 04 03 02 26 15 07 50 10 09 07 07 6B 03 0C 00 20 00 B8 2D E3 05 03 01 02 20 3A 80 18 71 38 2D 40 58 2C 04 05 7E 8A 42 00 00 30 1E...

Page 12: ...be should be within 10cm and perpendicular of the module surface 80 100 3 Aging time After Aging Start Keep the Power ON status during 5 Minutes In case of LCD Back light on should be checked using no signal or Full white pattern 6 Reference White Balance Adj coordinate and color temperature Luminance 216 Gray Standard color coordinate and temperature using CS 1000 over 26 inch Standard color coor...

Page 13: ... to move on to next process 6 2 Checkpoint TEST voltage GND 1 5KV min at 100mA SIGNAL 3KV min at 100mA TEST time 1 second TEST POINT GND TEST POWER CORD GND SIGNAL CABLE METAL GND Internal Pressure TEST POWER CORD GND LIVE NEUTRAL LEAKAGE CURRENT At 0 5mArms 7 USB S W Download option 1 Put the USB Stick to the USB socket 2 Automatically detecting update file in USB Stick If your downloaded program...

Page 14: ... Voltage is dependent on model 32 36LH20 32LH30 24V 19 22LH20 15V pin1 or 2 Replace Power board Replace X100 OK Check Fuse OK No Check P700 PWR_ON 2pin 5V OK Re download software No OK Check Q706 output level 5V Replace Q706 No Replace Mstar IC100 or Main board OK Replace Power board No Check inverter control error P700 22pin Low P700 20pin high OK Check Power board or Module No Check Mstar LVDS o...

Page 15: ...IC1002 Check IC1005 19 22 No Check IF_P N Signal OK Bad Tuner Replace Tuner No Replace X1005 No OK Check Mstar LVDS output R812 R813 R821 Check IC1004 LGDT Output AR1070 AR1071 OK Replace IC1004 No Replace Mstar IC100 or Main board No 3 Analog TV Video Check RF cable Check Tuner 5V Power IC1001 4pin OK Check CVBS signal TU1001 19 Pin Check IC1002 Check IC1005 19 22 No OK Replace Tuner No OK Check ...

Page 16: ... No OK Check Mstar LVDS output Replace Mstar IC100 or Main board No 5 RGB Video Check RGB Cable conductors for damage Check JK1204 OK OK Check input signal format Is it supported OK Check signal R G B H V Sync C113 C108 C114 R146 R149 Replace Jack No Check EDID OK Replace the defective IC or re download EDID data No Check other set If no problem check signal line No OK Check Mstar LVDS output Repl...

Page 17: ... output Replace Mstar IC100 or Main board No Check HDMI Cable conductors for damage of open conductor Check JK500 501 502 OK OK Check input signal format Is it supported OK Check EDID EEPROM IC500 501 502 I2C Signal Replace Jack No Replace the defective IC or re download EDID data No Check HDCP key NVRAM IC105 power I2C Signal 5 6 Replace the defective IC No OK Check HDMI Signal Check other set If...

Page 18: ...ER Menu Menu Sound TV Speaker Toggle the menu OK Check Mstar AUDIO_MASTER_CLK R603 OK Check Connector P600 Check Regulator IC601 IC704 No Check signal line Or replace IC100 No Replace Mstar IC100 or Main board No No Check Output Signal P600 1 2 3 4 pin OK Replace NTP Audio AMP IC500 No Replace connector if found to be damaged No OK Check speaker resistance and connector damage Replace speaker No 2...

Page 19: ...ource audio trouble shooting guide Replace Mstar IC100 or Main board No 9 Digital TV Audio Check Tuner 5V Power TU1001 4pin Check IC1002 Check IC1005 19 22 No OK Check IF_P N Signal Bad Tuner Replace Tuner No OK Check Demodulator Input Clock X1005 Replace X1005 No OK Check IC400 LGDT Output AR1070 AR1071 Replace IC400 No OK Check Output Signal P600 1 2 3 4 pin Replace NTP Audio AMP IC500 No OK Che...

Page 20: ...15 DQS DM Addr ctrl data MAX3232 Saturn5 ATSC US MPEG2 Linux Scaler Data 0 7 IF SIF TU_CVBS Reset IF_AGC SDA SCL_5V JTAG CLK TDI TDO MS RST Addr 0 1 CS Audio L R Audio L R for RGB HDMI 2 SPDIF RX TX RX TX JACK PACK at REAR JACK PACK at SIDE SCL SDA_3 3V TR Buffer VSB Demod LGDT3305 X tal Reset Switch Reset IC 12MHz TS In 0 7 TS_clk SOP Val EEPROM Data 16 31 DDR2 512Mbit Qimonda Hynix AV Component ...

Page 21: ...lectrical and mechanical parts in this chassis have special safety related characteristics These parts are identified by in the Schematic Diagram and EXPLODED VIEW It is essential that these special safety parts should be replaced 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 manufac...

Page 22: ...Copyright 2009 LG Electronics Inc All right reserved Only for training and service purposes LGE Internal Use Only ...

Page 23: ...Copyright 2009 LG Electronics Inc All right reserved Only for training and service purposes LGE Internal Use Only ...

Page 24: ...Copyright 2009 LG Electronics Inc All right reserved Only for training and service purposes LGE Internal Use Only ...

Page 25: ...Copyright 2009 LG Electronics Inc All right reserved Only for training and service purposes LGE Internal Use Only ...

Page 26: ...Copyright 2009 LG Electronics Inc All right reserved Only for training and service purposes LGE Internal Use Only ...

Page 27: ...Copyright 2009 LG Electronics Inc All right reserved Only for training and service purposes LGE Internal Use Only ...

Page 28: ...Copyright 2009 LG Electronics Inc All right reserved Only for training and service purposes LGE Internal Use Only ...

Page 29: ...Copyright 2009 LG Electronics Inc All right reserved Only for training and service purposes LGE Internal Use Only ...

Page 30: ...Copyright 2009 LG Electronics Inc All right reserved Only for training and service purposes LGE Internal Use Only ...

Page 31: ...Jan 2009 Printed in Korea P NO MFL41946814 ...