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- 18 -

LGE Internal Use Only

Copyright © 2008 LG Electronics. Inc. All right reserved. 
Only for training and service purposes

6. HDMI doesn’t display

Check input connect J900 , J901, J902

Can you see the normal waveform?

Check DDC communication lines(IC900, IC901,

IC903 Pin5,6)

Check the input of HDMI Seitch(IC902)

This signal is TMDS.

Can you see the normal waveform?

YES

YES

NO

J900 , J901, J902

may have problem. Replace this Jack.

Check the output of HDMI Switch(IC902).

Can you see the normal waveform?

YES

YES

NO

After checking the trace of TMDS lines and power of HDMI

Switch, you should decide to replace HDMI Switch  or not.

NO

NO

After checking the Power of this chip, you should

decide to replace this or not.

After checking the Power of HDMI Switch you should

decide to replace MST3361 or not.

YES

Check HDCP communication lines(IC902)

NO

After checking the Power of this chip, you should

decide to replace this or not.

Check the output  of Main IC(IC100).

Especially you should check

The H,V sync and clock.

Can you see the normal waveform?

YES

NO

After checking the Power of Main IC(IC100) you

should decide to replace Main IC or not.

This board has big problem because Main IC(IC100)

have some troubles.

After checking thoroughly all path once again, You

should decide to replace Main Board or not.

Содержание LB81D

Страница 1: ...LCD TV SERVICE MANUAL CAUTION BEFORE SERVICING THE CHASSIS READ THE SAFETY PRECAUTIONS IN THIS MANUAL CHASSIS LB81D MODEL 42LG70YD 42LG70YD AA website http biz LGservice com Internal Use Only ...

Страница 2: ...yright 2008 LG Electronics Inc All right reserved Only for training and service purposes CONTENTS CONTENTS 2 PRODUCT SAFETY 3 SPECIFICATION 6 ADJUSTMENT INSTRUCTION 9 TROUBLE SHOOTING 15 BLOCK DIAGRAM 19 EXPLODED VIEW 21 SVC SHEET ...

Страница 3: ...fe to 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 term...

Страница 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...

Страница 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 replac...

Страница 6: ...LGE Spec Storage Environment 1 Temp 20 60 deg 2 Humidity 85 1 Application range This specification is applied to the LCD TV used LB81A chassis 2 Requirement for Test Each part is tested as below without special appointment 1 Temperature 25 5ºC 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 ...

Страница 7: ...366 768 47 56 59 6 84 75 WXGA 8 1280 1024 63 595 60 0 108 875 SXGA 9 1920 1080 66 647 59 988 138 625 WUXGA 5 Component Video Input Y PB PR No Specification Remark Resolution H freq kHz V freq Hz 1 720x480 15 73 59 94 SDTV DVD 480i 2 720x480 15 75 60 SDTV DVD 480i 3 720x480 31 47 59 94 SDTV 480p 4 720X480 31 5 60 SDTV 480p 5 720x576 15 625 50 SDTV DVD 576i 6 720x576 31 25 50 SDTV 576p 7 1280x720 44...

Страница 8: ...1 720 480 31 47 59 94 27 00 SDTV 480P 4 3 2 720 480 31 50 60 27 027 SDTV 480P 4 3 3 640 480 31 469 59 94 25 175 SDTV 480P 4 3 4 640 480 31 469 60 00 25 20 SDTV 480P 4 3 5 720 480 31 47 59 94 27 000 SDTV 480P 16 9 6 720 480 31 50 60 00 27 027 SDTV 480P 16 9 7 720 576 31 25 50 00 27 000 SDTV 576P 8 1280 720 37 50 50 00 74 176 HDTV 720P HDCP 9 1280 720 44 96 59 94 74 176 HDTV 720P HDCP 10 1280 720 45...

Страница 9: ...ection 3 Main PCB check process APC After Manual Insult executing APC Download 1 Execute ISP program Mstar ISP Utility and then click Config tab 2 Set as below and then click Auto Detect and check OK message If display Error Check connect computer jig and set 3 Click Connect tab If display Can t Check connect computer jig and set 4 Click Read tab and then load download file XXXX bin by clicking Re...

Страница 10: ...e by pushing ADJ key execute ADC Adjust by pushing G key at ADC CALIBRATION RGB PC 2 COMPONENT input ADC 1 Component Gain Offset Adjustment Convert to Component in Input source Signal equipment displays Impress Resolution 480i MODEL 209 in Pattern Generator 480i Mode Pattern 65 in Pattern Generator MSPG 925 Series MPSG 1025D 7 color bar Impress Resolution 1080i Model 223 in Pattern Generator 1080i...

Страница 11: ...gram 4 4 EDID DATA No USE the EDID data of Digital data HDMI 1 2 3 4 and Analog EDID data RGB As EDID data is recorded in the Mstar Main IC Except for RGB EDID data 1 ANALOG DATA 128Byte 2Bi EDID block 0 Bytes 0 127 00H 7FH Block Type EDID 1 3 2 DIGITAL DATA HDMI 1 256Byte EDID block 0 Bytes 0 127 00H 7FH Block Type EDID 1 3 EDID block 1 Bytes 128 255 80H FFH Block Type CEA EDID Timing Extension V...

Страница 12: ...40 58 2C 40 45 00 C4 8E 21 00 00 1E 01 1D 00 BC 52 D0 1E 20 50 B8 28 55 40 C4 8E 21 00 00 1E 00 00 00 FD 00 30 60 58 1F 64 11 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 6B 0 1 2 3 4 5 6 7 8 9 A B C D E F 0 02 03 23 F1 4E 93 14 12 04 05 03 02 20 1F 21 22 10 10 07 16 23 15 07 50 83 01 00 00 67 03 0C 00 20 20 00 B8 2D 01 1D 80 D0 72 1C 16 20 10 2C 25 80 C4 30 ...

Страница 13: ... E8 00 data EEPROM Write by some values COLOR SAVE EB 00 00 Color Save R G B cutoff Drive Contrast Bright H POSITION 20 00 00 64 They have different V POSITION 30 00 00 64 range each mode CLOCK 90 00 00 64 FOS Adjustment PHASE 92 00 00 64 R DRIVE 16 00 cool 00 80 Drive adjustment 01 medium 02 warm G DRIVE 18 00 cool 00 80 01 medium 02 warm B DRIVE 1A 00 cool 00 80 01 medium 02 warm R CUTOFF 80 00 ...

Страница 14: ...2 PROM 5 7 VRAM Read Send CMD 70h to read Video RAM value from MICOM And save its value to 128 Bytes Buffer Common Buffer for the use of EDID Delay 500ms Time to Wait and Read Video RAM from MICOM Be transmitted the contents of MICOM s 128 bytes Buffer to PC 128th Data is the CheckSum of 127 bytes data That s OK if the value of adding 128 bytes Data is Zero 14 LGE Internal Use Only Copyright 2008 ...

Страница 15: ...t NO After checking the Power of Main IC IC100 you should decide to replace Main IC or not This board has big problem because Main IC IC100 have some troubles After checking thoroughly all path once again You should decide to replace Main Board or not Check the output data of TU401 Pin 24 34 Can you see the normal signal NO Could you measure voltage of TU800 IIC lines Are they all normal NO You sh...

Страница 16: ...path once again You should decide to replace Main Board or not 4 Component doesn t display Check J701 Can you see the normal waveform Check the input of Component Audio switch IC1001 Can you see the normal waveform YES YES NO J701 may have problem Replace this Jack NO After checking the Power of component Audio switch you should decide to replace component Audio switch or not After checking the Po...

Страница 17: ...B Audio switch or not NO After checking the Power of RGB Audio switch you should decide to replace RGB Audio switch or not Check the output of Main IC IC100 Especially you should check The H V sync and clock Can you see the normal waveform YES NO After checking the Power of Main IC IC100 you should decide to replace Main IC or not This board has big problem because Main IC IC100 have some troubles...

Страница 18: ...and power of HDMI Switch you should decide to replace HDMI Switch or not NO NO After checking the Power of this chip you should decide to replace this or not After checking the Power of HDMI Switch you should decide to replace MST3361 or not YES Check HDCP communication lines IC902 NO After checking the Power of this chip you should decide to replace this or not Check the output of Main IC IC100 E...

Страница 19: ... 35 OUT_N_L 29 IN_L 38 IN_R 5 HP_DET 37 MUTE 6 AUOUTR0 80 AUOUTL0 79 GPIO12 45 LVDS 177 190 194 199 RXE RXO BIN 1 SOGIN 2 GIN 3 RIN 4 VS_RGB 7 HS_RGB 8 SCL RX 33 SDA TX 34 DM_DET PB_IN 11 SOY 13 Y_IN 14 PR_IN 16 AUL_IN1 70 AUR_IN1 71 CVBS1 30 AUL_IN0 68 AUR_IN 69 SV_C0 25 SV_Y0 26 GPIO15 48 6612F00099A 0 27617 EAG31022001 0 185 Tx Rx IC603 MAX3232CDR Tx_Out Rx_In R232C_TXD R232C_RXD EEPROM AT24C02...

Страница 20: ...TSVALID 104 IN 256 OUT 255 2 3 3V 1 8V HP_OUT_L 42 HP_OUT_R 1 OUT_P_R 8 OUT_N_R 14 OUT_P_L 35 OUT_N_L 29 IN_L 38 IN_R 5 HP_DET 37 MUTE 6 12V AUOUTR0 80 AUOUTL0 79 GPIO12 45 LVDS 177 190 194 199 RXE RXO BIN 1 SOGIN 2 GIN 3 RIN 4 VS_RGB 7 HS_RGB 8 SCL RX 33 SDA TX 34 DM_DET AUR_IN3 76 AUL_IN3 75 PB_IN 11 SOY 13 Y_IN 14 PR_IN 16 AUL_IN1 70 AUR_IN1 71 CVBS1 30 AUL_IN0 68 AUR_IN 69 SV_C0 25 SV_Y0 26 GP...

Страница 21: ...ectrical 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 manufact...

Страница 22: ...Copyright 2008 LG Electronics Inc All right reserved Only for training and service purposes LGE Internal Use Only ...

Страница 23: ...Copyright 2008 LG Electronics Inc All right reserved Only for training and service purposes LGE Internal Use Only ...

Страница 24: ...Copyright 2008 LG Electronics Inc All right reserved Only for training and service purposes LGE Internal Use Only ...

Страница 25: ...Copyright 2008 LG Electronics Inc All right reserved Only for training and service purposes LGE Internal Use Only ...

Страница 26: ...Copyright 2008 LG Electronics Inc All right reserved Only for training and service purposes LGE Internal Use Only ...

Страница 27: ...Copyright 2008 LG Electronics Inc All right reserved Only for training and service purposes LGE Internal Use Only ...

Страница 28: ...Copyright 2008 LG Electronics Inc All right reserved Only for training and service purposes LGE Internal Use Only ...

Страница 29: ...Copyright 2008 LG Electronics Inc All right reserved Only for training and service purposes LGE Internal Use Only ...

Страница 30: ...Copyright 2008 LG Electronics Inc All right reserved Only for training and service purposes LGE Internal Use Only ...

Страница 31: ...Jun 2008 Printed in Korea P NO MFL47147102 ...

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