LG 55SK8550PUA Service Manual Download Page 21

Page: 21 / 98

- 21 -

Only for training and service purposes.

(4) Hold the left bottom handle and lift the B/C. At the same time, gently pushing the left side of the B/C toward the inside of the set.

(Separate the B/C from bottom to top direction)

* If push with strong force from left side, Side Latch will break.

Handle L

<4-1>

<4-2>

Summary of Contents for 55SK8550PUA

Page 1: ...facsimile or other electronic means publication modification copying or transmission of this Service Manual is STRICTLY PROHIBITED unless you have obtained the prior written consent of the LG Electronics entity from which you received this Service Manual The material covered by this prohibition includes without limitation any text graphics or logos in this Service Manual Copyright 2018 LG Electron...

Page 2: ...hts reserved Only for training and service purposes CONTENTS CONTENTS 2 SAFETY PRECAUTIONS 3 SERVICING PRECAUTIONS 4 SPECIFICATION 6 SOFTWARE UPDATE 9 BLOCK DIAGRAM 10 EXPLODED VIEW 18 ASSEMBLY DISASSEMBLY 19 TROUBLE SHOOTING GUIDE APPENDIX ...

Page 3: ...he set is safe 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 ...

Page 4: ...c charge on your body by touching a known earth ground Alter natively obtain and wear a commercially available discharging wrist strap device which should be removed to prevent poten tial 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 electrosta...

Page 5: ...oints 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 replaced component...

Page 6: ...part number in accordance with BOM 5 The receiver must be operated for about 5 minutes prior to the adjustment 3 Test method 1 Performance LGE TV test method followed 2 Demanded other specification Safety CE IEC specification EMC CE IEC 4 General Specification No Item Specification Remark 1 Market North America 2 Broadcasting system ATSC NTSC M 64 256 QAM 3 Available Channel VHF 02 13 UHF 14 69 DT...

Page 7: ...4 25 17 VESA VGA 4 800 600 37 87 60 31 40 VESA SVGA 5 1024 768 48 36 60 00 65 VESA XGA 6 1360 768 47 71 60 01 84 75 VESA WXGA 7 1152 864 54 34 60 05 80 VESA 8 1280 1024 63 98 60 02 109 00 SXGA Support to HDMI PC 9 1920 1080 67 5 60 158 40 WUXGA Reduced Blanking 10 1920 1080 135 120 297 UDTV 1080P 11 3840 2160 54 24 00 297 00 UDTV 2160P 12 3840 2160 56 25 25 00 297 00 UDTV 2160P 13 3840 2160 67 5 3...

Page 8: ...6 HDTV 1080P 17 1920 1080p 33 71 29 97 79 120 HDTV 1080P 18 1920 1080p 33 75 30 00 79 20 HDTV 1080P 19 1920 1080p 56 25 50 00 148 5 HDTV 1080P 20 1920 1080p 67 43 59 94 148 35 HDTV 1080P 21 1920 1080p 67 5 60 00 148 50 HDTV 1080P 22 1920 1080p 112 5 100 297 00 UDTV 1080P 23 1920 1080p 134 86 119 88 296 70 UDTV 1080P 24 1920 1080p 135 00 120 297 UDTV 1080P 25 3840 2160p 53 95 23 98 296 70 UDTV 2160...

Page 9: ... About This TV page for update 5 TV is updating 6 After finished the update below Pop up appear 7 Click Yes TV will be DC OFF ON 8 After TV turned on Check the updated SW Version and Tool Option 2 NSU This Function is needed to connect to the internet 1 Menu All Settings General About This TV 2 Click CHEK FOR UPDATES system check newest version 3 Click DOWNLOAD AND INSTALL 4 TV is updating 5 After...

Page 10: ...T ETHERNET I2C 1 SUB ASSY IR KEY ST BY LED WIFI BT Combo USB_WIFI CVBS SIF HDMI3 HDMI 2 0 USB2 2 0 HDMI2 ARC HDMI 2 0 DATA CLK USB3_0 USB2_2 PHY2_RX0N PHY1_RX0N I2C6 HDMI4 HDMI 2 0 PHY0_RX0N PMIC Sub PMIC DDR4 2666 512MB 1GB DDR4 2666 512MB 1GB DDR3 2133 512MB DDR3 2133 512MB USB3 2 0 USB2_1 Side Rear TU6701 IF X101 I2C 0 Sub Audio AMP I2C 5 Side Rear IC400 IC401 IC501 IC502 IC102 IC8800 IC8000 IC...

Page 11: ...ing and service purposes SCL0 SDA0 100Ω 3 3KΩ 3 3V_NORMAL 3 3KΩ 33Ω IC102 NVRAM 3 3V_NORMAL IC5300 SCL2 SDA2 TUNER SCL4 SDA4 33pF SCL5 SDA5 1 8KΩ SCL1 SDA1 IC3000 MICOM 33Ω 3 3KΩ 3 3V_NORMAL 3 3KΩ 3 3V_NORMAL IC8000 33Ω IC8100 33Ω 47pF 3 3V_TU IC5400 33pF Main IC 2 I2C ...

Page 12: ...00 4A Audio AMP DDR3 3 3V_NORMAL 3 5V_ST 1 8V_IO IC2100 3A 0 9V_CPU 0 9V_CORE A20V USB1 2 0 USB2 2 0 PANEL IC1500 3 5A 1 5V_DDR MICOM IR_KEY ETHERNET WIFI 3 5V_WOL WIFI_EN Main IC Main IC Main IC6900 2A 0 9V_DDR C4TX NVRAM H P AMP 1 1V_DEMOD TUNER Audio AMP RS232 Control IC IC2300 2A AVDDT_EPI_C4TX Main IC USB1 2 0 Audio AMP Center woofer IC1501 3 5A IC1502 1A DDR4 DDR4 1 2V_DDR 2 5V_VPP Main IC 3...

Page 13: ...1_TS_DATA 4 22 FE_DEMOD1_TS_DATA 5 23 FE_DEMOD1_TS_DATA 6 24 FE_DEMOD1_TS_DATA 7 25 3 3V_TU SCL_RF 1 SDA_RF 2 SIF 6 CVBS 4 IF_AGC 5 RESET_DEMOD 10 FILTER FE_DEMOD1_TS_CLK FE_DEMOD1_TS_SYNC FE_DEMOD1_TS_VAL FE_DEMOD1_TS_DATA 0 7 33 Ω IF_P_TU IF_N_TU TU_CVBS IF_AGC IF_P_MAIN IF_N_MAIN TU_RESET1 GPIO26 CVBS_IN1 IFAGC 3 3V_TU 1 2KΩ TP_DVB_CLK TP_DVB_SOP TP_DVB_VAL TP_DVB_DATA0 TP_DVB_DATA1 TP_DVB_DATA...

Page 14: ... LPF AUDA_OUTL_CH1 AUDA_OUTR_CH1 TUNER_SIF IC3000 MICOM AMP_MUTE GPIO23 AMP_RESET_N JK3403 JK6200 LPF Front_L Front_R DACSCK GPIO81 SDA0 GPIO138 SCL0 GPIO139 AUD_LRCK AUD_LRCH IC6300 EAN62668301 I2C_SDA_0_AMP1 I2C_SCL_0_AMP1 DACLRCH GPIO82 DACLRCK AUD_SCK SIDE_HP_MUTE IC5400 Front AMP LPF LPF CenterL CenterR AUD_LRCK AUD_LRCH I2C_SDA_0_AMP1 I2C_SCL_0_AMP1 AUD_SCK Main IC 5 Audio Out ...

Page 15: ...Link 8bits DDC_SCL_4 DDC_SDA_4 TMDS Link 8bits TMDS DATA 6bits DATA0 1 2 TMDS CLK 2bits TMDS Link 8bits HDMI_CEC_MICOM Q3001 DDC_SCL_1 DDC_SDA_1 JK3104 JK3102 JK3101 J J J J J J J J J J J J K K K K K K K K K K K K K K K K K K 1 31 31 31 31 31 31 3 3 3 1 31 31 31 3 3 10 0 0 0 0 0 0 0 0 0 0 0 0 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 HDMI3 SIDE HDMI2 0 JK3103 DDC_SCL_3 DDC_SDA_3 TMDS Link 8bits ...

Page 16: ... USB_OCD2 WIFI_DM WIFI_DP USB2_2_DM0 USB2_2_DP0 MICOM IC3000 UART0_TXD GPIO105 UART0_RXD GPIO106 SOC_TX SOC_RX IC7200 USB2 0 WIFI Combo BT_RESET BT_WAKEUP_DEVICE BT_WAKEUP_HOST OCP IC4301 OCP IC4501 5V_NORMAL 5V_NORMAL JK4400 JK4200 USB2 0 Main IC USB2 0_2_DM1 USB2 0_2_DP1 OCP IC4700 5V_NORMAL USB3 Rear 5V_USB_3 USB_CTL2 USB_OCD2 JK4600 USB2 0_3_DM0 USB2 0_3_DP0 USB2 0 7 USB WIFI M REMOTE UART ...

Page 17: ...LG Electronics Inc All rights reserved Only for training and service purposes TX 6lane Main IC I2C TS CIC_Data P7801 P7800 TX 6lane Lock_In PMIC IC8000 Sub PMIC IC8100 GMA CLK GMA CLK VCOM VCOM 8 EPI 68Pin Interface ...

Page 18: ...stics These parts are identified by in the EXPLODED VIEW It is essential that these special safety parts should be replaced with the same components as recommended in this manual to prevent Shock Fire or other Hazards Do not modify the original design without permission of manufacturer IMPORTANT SAFETY NOTICE 200A 400 540 521 800 LV1 LV2 530 820 120 121 910 900 AR2 A9 A10 700 HP1 HS1 350 200 200D ...

Page 19: ...nc All rights reserved Only for training and service purposes ASSEMBLY DISASSEMBLY GUIDE Disassembly Guide 1 Lay the TV Set on a flat Pad and Remove the stand screw 4ea After separate stand cover Remove the stand screw 4ea SK85 SK95 ...

Page 20: ...crew 5ea Additional for 65 Remove 1ea Screw of the Power Cord Bracket 3 After recognizing a B C Ready to remove the B C 65SK85 95 Latch 18 Point 65SK85 95 Screw 6 Point 55SK85 95 Screw 5 Point 55SK85 95 Latch 16 Point 49SK85 Screw 5 Point 49SK85 Latch 14 Point B C assembly structure Module Plate Spring BackCover Latch Plate Spring ...

Page 21: ...ses 4 Hold the left bottom handle and lift the B C At the same time gently pushing the left side of the B C toward the inside of the set Separate the B C from bottom to top direction If push with strong force from left side Side Latch will break Handle L 4 1 push 4 2 Up push Up push Up Up ...

Page 22: ... 5 Hold the right bottom handle and lift the B C At the same time gently pushing the right side of the B C toward the inside of the set Separate the B C from bottom to top direction If push with strong force from right side Side Latch will break Handle R 5 2 5 3 push Up 5 1 push Up push Up Up ...

Page 23: ...f the B C After with one hand pushing the B C in the upward direction and at the same time with the other hand tap the right bottom of the B C 2 or 3 times in the upward direction 7 With one hand Pushing the B C in the upward direction and at the same time With the other hand tap the left bottom of the B C 2 or 3 times in the upward direction 8 12cm ...

Page 24: ...direction and simultaneously With the other hand tap the center bottom of the B C 2 or 3 times in the upward direction And Make sure that the top of the B C is completely separated from the plate spring If Push the bottom of the B C upwards with a strong force Top Latch may break 9 Supports the bottom of the B C center Check the Latch separation ...

Page 26: ...ce purposes Assembly Guide 1 Place the B C in the module plate spring and Press Latch Points to assemble the B C 2 Check whether gap occurs in the Top left side right side of the B C 65SK85 95 Latch 18 Point 55SK85 95 Latch 16 Point 49SK85 Latch 14 Point push plate Spring B C Latch ...

Page 27: ... reserved Only for training and service purposes 3 Assemble the Bottom screw 5ea For 65 After assemble the Power Cord Bracket assemble the 1ea Screw 65SK85 95 65SK85 95 Screw 6 Point 55SK85 95 Screw 5 Point 55SK85 95 49SK85 Screw 5 Point 49SK85 ...

Page 30: ...while viewing power auto on off 7 8 8 C Audio error No audio Normal video 9 9 Wrecked audio discontinuation noise 10 10 D Function error Remote control Local switch checking 11 Motion remote operating checking 12 11 12 Wifi operating checking 13 13 External device recognition error 14 14 E Noise Circuit noise mechanical noise 15 15 F Exterior error Exterior defect 16 First of all Check whether the...

Page 31: ...ys check record S W Version and White Balance value before replacing the Main Board Replace Main Board Re enter White Balance value Precaution Established date Standard Repair Process Revised date 1 16 Error symptom A Video error No video Normal audio A9 A9 A4 A2 First of all Check whether all of cables between board is inserted properly or not Main B D Power B D EPI Cable Speaker Cable IR B D Cab...

Page 32: ...audio Check and replace MAIN B D Y Replace Power Board and repair parts N End Standard Repair Process A Video error No video No audio A9 Established date Revised date 2 16 Error symptom 2 Copyright 2018 LG Electronics Inc All rights reserved Only for training and service purposes ...

Page 33: ...g By using Digital signal level meter By using Diagnostics menu on OSD All Settings Channels Channel Tuning Manual Tuning Check the Signal Signal strength Normal over 50 Signal Quality Normal over 50 Normal Picture Y Contact with signal distributor or broadcaster Cable or Air N Normal Picture Y Close N A4 Standard Repair Process Established date Revised date 3 16 Error symptom 3 N Y Close N S W Up...

Page 34: ...ck external device and cable Y External device Cable normal HDMI error Check external device and cable Replace Main B D Replace Main B D N N A Video error Color error A6 N Y End Replace module Request repair for external device cable Color error Check Test pattern A15 A7 Standard Repair Process Established date Revised date 4 16 Error symptom 4 Copyright 2018 LG Electronics Inc All rights reserved...

Page 35: ...I by connecting Jig pattern Generator Set top Box etc N Y Replace Main B D Module Screen normal Check screen condition by input External Input AV HDMI DVI Request repair for external device HDMI DVI Connect other external device and cable Check normal operation of External Input Component RGB and HDMI DVI by connecting Jig pattern Generator Set top Box etc Replace Main B D Module Screen normal N Y...

Page 36: ...ure voltage of each output of Power B D N Y Normal voltage Replace Main B D Y OK Replace Main B D N Y Normal Check ST BY 7 8V Replace Power B D N Y Normal voltage Replace Power B D Y A8 A9 A9 A9 Standard Repair Process Established date Revised date 6 16 Error symptom 6 Stand By Red or Turn On Operating Turn Off Close Copyright 2018 LG Electronics Inc All rights reserved Only for training and servi...

Page 37: ...TE CONTROL POWER_OFF_BY_OFF_TIMER Power off by OFF TIMER POWER_OFF_BY_SLEEP_TIMER Power off by SLEEP TIMER POWER_OFF_BY_INSTOP Power off by INSTOP KEY POWER_OFF_BY_AUTO_OFF Power off by AUTO OFF POWER_OFF_BY_ON_TIMER Power off by ON TIMER POWER_OFF_BY_RS232C Power off by RS232C POWER_OFF_BY_RESREC Power off by Reservated Record POWER_OFF_BY_RECEND Power off by End of Recording POWER_OFF_BY_SW_DW P...

Page 38: ...gh Check fail after multi power on Check Change Power B D CPUABNORMAL If the CPU attempts to reset in case of abnormal operation and Shut Down in case of failure Check Change Main B D NO POLING Power off when receiving no ack RESULT TV power off on Reboot CONDITION There is no I2C response from CPU for 15 seconds Check Change Main B D CPUCMD Power off by main SoC command Check Change Main B D INV_...

Page 39: ...Power Board and repair parts Check Speaker disconnection N Y connecting Speaker Replace MAIN Board End C Audio error No audio Normal video A11 A12 A9 Disconnection Established date Revised date 9 16 Error symptom Standard Repair Process 9 Copyright 2018 LG Electronics Inc All rights reserved Only for training and service purposes ...

Page 40: ...ernal Input Connect and check other external device N Y Normal audio Check and fix external device Replace Power B D N Y Normal voltage Check input signal RF External Input signal Signal normal When RF signal is not received Request repair to external cable ANT provider Y Check audio B Voltage 20V Replace Main B D In case of External Input signal error Check and fix external device Replace Main B ...

Page 41: ...heck Replace Baterry of R C Check Repair Cable connection Connector solder Normal operating Check B 3 5V On Main B D A13 Normal Voltage Close N N Check 7 8V on Power B D Replace Power B D or Replace Main B D Power B D don t have problem A9 Check IR Output signal Normal Signal N Y Repair Replace IR B D N A13 Replace Main B D Y A13 Standard Repair Process Established date Revised date 11 16 Error sy...

Page 42: ...Is show ok message N N N Y Replace MR18 Turn off on the set and press the wheel Press the back key about 5sec If you conduct the loop at 3times change the MR18 Y Check the INSTART menu RF Receiver ver is 00 00 Y Check Repair RF assy connection N Down load the Firmware INSTART MENU 12 RF Remocon Test Receiver Firmware download Y RF Receiver ver is 00 00 N A14 A4 A4 Close Close Close Close 12 Copyri...

Page 43: ...ifi cable connection N Check the Wifi wafer 1pin Standard Repair Process Established date Revised date 13 16 Error symptom 13 Change the Wifi assy Normal Voltage Y Y N Replace Main B D Wi Fi Mac value is NG N A14 A4 A4 A14 Close Close Copyright 2018 LG Electronics Inc All rights reserved Only for training and service purposes ...

Page 44: ... fix external device cable HDMI DVI Optical Recognition error Replace Main B D Replace Main B D Fix in accordance with technical information D Function error External device recognition error Established date Revised date 14 16 Error symptom Standard Repair Process 14 Copyright 2018 LG Electronics Inc All rights reserved Only for training and service purposes ...

Page 45: ...d as shown in the solution manual For models without any fix information provide the description Mechanical noise is a natural phenomenon and apply the 1st level description When the customer does not agree apply the process by stage Describe the basis of the description in Part related to nose in the Owner s Manual E Noise Circuit noise mechanical noise Established date Revised date 15 16 Error s...

Page 46: ...e cabinet Replace remote control Remote control damage Stand dent Replace stand F Exterior defect Exterior defect Established date Revised date 16 16 Error symptom Standard Repair Process 16 Copyright 2018 LG Electronics Inc All rights reserved Only for training and service purposes ...

Page 47: ... 4 Version checking method A4 5 Tuner Checking Part A5 6 A Video error _Vertical Horizontal bar residual image light spot Connection diagram A6 7 A Video error_ Color error Check Link Cable EPI reconnection condition A7 9 Appendix Cable 1 2 A 1 11 A 2 11 Exchange Main Board 1 3 A 3 11 A 5 11 Exchange Module 1 3 A 6 11 A 10 11 T con 1 2 A 9 11 A 10 11 Exchange Power Board PSU A 11 11 Copyright 2018...

Page 48: ...mal video Checking method in menu when there is no audio A12 15 Voltage and speaker checking method when there is no audio A13 16 D Function error Remote control operation checking method A14 17 Motion Remote Wifi operation checking method A15 18 E Etc How to use the Service remote control A16 A18 19 After changing Main Board Checking list A19 20 Operation Test Pattern ADJ A20 21 How to use JIG Po...

Page 49: ...eck EPI Lock A Video error_No video Normal audio After Remove the Rear Cover turning on the power and check with the naked eye Whether you can checking voltage of R7801 R7801 1 8V normal Copyright 2018 LG Electronics Inc All rights reserved Only for training and service purposes ...

Page 50: ...audio Entry method 1 Press the ADJ button on the remote control for adjustment 2 Enter into White Balance of item 12 3 After recording the R G B GAIN Cut value of Color Temp Cool Medium Warm re enter the value after replacing the MAIN BOARD Copyright 2018 LG Electronics Inc All rights reserved Only for training and service purposes ...

Page 51: ...nput signal strength checking method A Video error_Video error video lag stop All Settings Channels Channel Tuning Manual Tuning When the signal is strong use the attenuator 10dB 15dB 20dB etc Copyright 2018 LG Electronics Inc All rights reserved Only for training and service purposes ...

Page 52: ...ical Manual Error symptom Content TV Version checking method A Video error_Video error video lag stop Press the IN START with the remote control for adjustment Copyright 2018 LG Electronics Inc All rights reserved Only for training and service purposes ...

Page 53: ... signal strength or check whether the screen is normal when the external device is connected 2 After measuring each voltage from power supply finally replace the MAIN BOARD A5 Standard Repair Process Detail Technical Manual Error symptom Content TUNER checking part A Video error_Video error video lag stop Copyright 2018 LG Electronics Inc All rights reserved Only for training and service purposes ...

Page 54: ...date Error symptom Content A6 A6 Standard Repair Process Detail Technical Manual Error symptom Content TV Connection diagram A Video error _Vertical Horizontal bar residual image light spot As the part connecting to the external input check the screen condition by signal Copyright 2018 LG Electronics Inc All rights reserved Only for training and service purposes ...

Page 55: ...r symptom Content Check Link Cable EPI reconnection condition A Video error_Color error Check the contact condition of the Link Cable especially dust or mis insertion Copyright 2018 LG Electronics Inc All rights reserved Only for training and service purposes ...

Page 56: ...f FFC cable CABLE R Color Excessive Color is Excessive due to FFC Cable Contact CABLE Screen darkness screen is dark due to poor contact due to disconnection of the FFC cable pin CABLE G Color Excessive G color transient due to poor FFC cable connection Pin 단선 Copyright 2018 LG Electronics Inc All rights reserved Only for training and service purposes ...

Page 57: ...ead LVDS cable connection problem CABLE Color spread LVDS cable connection problem CABLE Screen stop Due to foreign substance withi nLVDS cable PIN Appendix Examples of Symptoms Image error Check for poor cable contact Copyright 2018 LG Electronics Inc All rights reserved Only for training and service purposes ...

Page 58: ...Main Screen noise Broken screen due to Main IC problem Main Dark picture Dark left side screen Main Broken picture Top bottom screen part Picture problem due to tuner Inner side quality problem Appendix Examples of Symptoms Main Copyright 2018 LG Electronics Inc All rights reserved Only for training and service purposes ...

Page 59: ...anner Main Screen spread Screen corner appears blurry Main Color Spread Color spread on the screen Main Blurry Screen Blurry picture on the screen Check parts by symptom Appendix Examples of Symptoms Main Copyright 2018 LG Electronics Inc All rights reserved Only for training and service purposes ...

Page 60: ...n problem Right side screen problem Main LG logo Screen problem Screen picture spread problem Main Right side picture problem No problem at the initial stage During Heat run right side picture problem Check parts by symptom Appendix Examples of Symptoms Main Copyright 2018 LG Electronics Inc All rights reserved Only for training and service purposes ...

Page 61: ...ange the module Module image broken Source Driver issue Module White dot White dot cause by panel issue Module Line Dim Vertical Line cause by source drive IC Check parts by symptom Appendix Examples of Symptoms Module Copyright 2018 LG Electronics Inc All rights reserved Only for training and service purposes ...

Page 62: ...e Module has damaged Module Line Defect Module has damaged Module Press damage Un repairable Cases In this case please exchange the module Check parts by symptom Appendix Examples of Symptoms Module Copyright 2018 LG Electronics Inc All rights reserved Only for training and service purposes ...

Page 63: ... repairable Cases In this case please exchange the module Module Green light Compensation error when Power On off Module Color difference Color difference between screen cause by compensation error Check parts by symptom Appendix Examples of Symptoms Module Copyright 2018 LG Electronics Inc All rights reserved Only for training and service purposes ...

Page 64: ...mage Module has damaged Can t fix it Module Burnt Burnt Can t fix it Module Mura Screen Mura Can t fix it Check parts by symptom Appendix Examples of Symptoms Module Copyright 2018 LG Electronics Inc All rights reserved Only for training and service purposes ...

Page 66: ...ate Revised date Error symptom Content TV A8 Standard Repair Process Detail Technical Manual A8 LED Error symptom Content Check front display LED B Power error _No power ST BY condition On or Off Power ON condition Turn Off Copyright 2018 LG Electronics Inc All rights reserved Only for training and service purposes ...

Page 67: ...BY 3 5V B Power error _No power TV A9 Standard Repair Process Detail Technical Manual A9 DC 13 2V line ST BY Votage 55 65SK9000PUA Power Board Voltage Current Error symptom Content Check power input voltage and ST BY 3 5V B Power error _No power Copyright 2018 LG Electronics Inc All rights reserved Only for training and service purposes ...

Page 68: ...rval 2 Condition Error message sent via LED flashing count when the LED driver is in an abnormal operation 3 Abnormal condition 1 Open LED Protection 2 Short LED Protection 3 DC DC Voltage Check 4 P Dim1 error 5 Driver On signal error 6 Local dimming data error 7 Driver IC error or MCU error Check 8 V sync No approve LED Error checking method Slim Direct Error symptom Content Check Power LED Indic...

Page 69: ...andard Repair Process Detail Technical Manual A11 ALL MODELS Entry method 1 Press the IN START button of the remote control for adjustment 2 Check the entry into adjustment item 3 Power On Off Status POWER OFF MODE checking method B Power error _Off when on off whiling viewing Error symptom Content Copyright 2018 LG Electronics Inc All rights reserved Only for training and service purposes ...

Page 70: ...tandard Repair Process Detail Technical Manual A12 Checking method in menu when there is no audio C Audio error_No audio Normal video Error symptom Content Checking method 1 Press the Setting button on the remote control 2 Select the Sound function of the Menu 3 Select the Sound Out 4 Select TV Speaker Copyright 2018 LG Electronics Inc All rights reserved Only for training and service purposes ...

Page 71: ...3 SPK_L FT 7 SPK_L CF 4 SPK_L FT 8 SPK_L CF Output Voltage Current STBY 7 56Vrms 9 24Vrms 17mA 0 17mA 13 2V 12 54V 13 86V 3 2A 0 1 3 2A 20 0V 18V 22V 0 8A 0 1 0 8A Output Inch Voltage Typycal VLED 65 85 35 115 91 V 96 7V 55 68 28V 92 77V 77 4V 49 71 6V 96 6V 77 7V Error symptom Content Voltage and speaker checking method when there is no audio C Audio error_No audio Normal video Connect the tester...

Page 72: ...YE_SCL 18 GND 19 IR 20 LED_R 21 GND 22 3 5V 23 KEY2 24 KEY1 25 GND LED Voltage and speaker checking method when there is no audio C Audio error_No audio Normal video A21 Established date Revised date Error symptom Content TV A14 Error symptom Content Remote control operation checking method D Function error Checking order to check remote control Checking order 1 2 Check IR cable condition between ...

Page 73: ...e condition between IR Main board 2 Check the 3 5V on the terminal 1 Checking order to check motion remote wifi Wifi BT Front Wifi BT Rear Pin Pin name 1 3 5V_WIFI 2 WIFI_DM 3 WIFI_DP 4 GND 5 WOL WIFI_PWR_ON 6 3 5V_WIFI 7 RESET 8 GND 9 BT_WAKE_UP_DEVICE 10 BT_WAKE_UP_HOST 11 GND 12 No Connection 13 No Connection 14 No Connection 15 No Connection 16 EYE_SDA 17 EYE_SCL 18 GND 19 IR 20 LED_R 21 GND 2...

Page 74: ...cal Manual How to use the Service remote control D Function error A16 A16 0 4 1 3 0 4 1 3 1 How to access the remote control Error symptom Content Copyright 2018 LG Electronics Inc All rights reserved Only for training and service purposes ...

Page 75: ...e Easy Picture Cinema Spots Game Custom PIcture1 Custom Picture2 Bright Picture SSM Added Function Standard user music cinema sports game standard user PIP Picture In Picture is activated TEXT Access to the Power Only mode CAP Broadcasting caption on off MPX Stereo mode mono stereo foreign language access Used when in factory mode Simplink Added Function Access to the Simplink connected device EYE...

Page 76: ...ction HDD USB external device s HDD screen is activated MENU User function gets activated EXIT Exit from the current mode TIME SHIFT Added function Moves forward backward of recorded contents MUTE Mute function 0 Volume IN STOP SET to factory mode VOL Volume Up Down CH Channel Up Down AV1 2 3 Added function Connects to external input 1 2 3 COMP1 2 Added function Connects to Component 1 2 HDMI1 2 3...

Page 77: ...tion error Standard Repair Process Detail Technical Manual After Changing Main Board Check list A19 After Changing Main Board Check list Model Number D L White Balance 7번 Choice a Model Number D L Model name Serial Number 백커버 뒤에 ID Label 확인하여 입력한다 1 Go to Instart button of Operation remote 2 Go to ADJ button of Operation remote 13번 White Balance로 진입 색온도의 R G B GAIN Cut 값을 기록한 후 메인보드 교체 A19 E Etc E...

Page 78: ...s of patterns using the CH or key Checking item 1 Defective pixel 2 Residual image 3 MODULE error ADD BAR SCAN BAR 4 Video error Classification of MODULE or Main B D Adjustment Test pattern E Etc Error symptom Content Copyright 2018 LG Electronics Inc All rights reserved Only for training and service purposes ...

Page 80: ...Y SJ UJ 28Pin 24Pin 18Pin 24Pin 24Pin 24Pin 28Pin 28Pin 18Pin 28Pin 28Pin 12Pin 12Pin 28Pin 12 13 14Y Smart JIG connector applied 24Pin 24Pin NC Includes 49UJ63 Defect diagnosis Power Board Main Board 16Y OLED 17Y OLED A21 2 19 SK85 SK96 SK95 SK99 UK64 UK65 Copyright 2018 LG Electronics Inc All rights reserved Only for training and service purposes ...

Page 81: ...LH66 LH60 LH54 17 OLED B7 C7 E7 G7 W7 17 LED SJ95 UJ98 SJ85 UJ94 SJ80 UJ77 UJ75 UJ78 UJ65 UJ68 UJ63 UJ67 LJ61 LJ68 LJ55 LJ58 15Y 16Y 17Y OLED Model 16Y 17Y LED Model Existing 12Y 13Y 14Y 15Y LED models included 15Y 16Y 17Y OLED 16 17 Y LED model Power diagnosis function newly added A21 3 19 Copyright 2018 LG Electronics Inc All rights reserved Only for training and service purposes ...

Page 82: ... POWER A 2013 Power Board Muitl Gender How to Connect Connect the Muiti Gender to the connector black as shown in picture 2 of the Smart JIG A21 4 19 Copyright 2018 LG Electronics Inc All rights reserved Only for training and service purposes ...

Page 83: ...sis can be made only if it is set correctly 24V Power Board Change the switch to 24V of Smart Jig Voltage 20V Power Board Change the switch to 24V of Smart Jig Voltage 13 2V 18V Power Board Change the switch to 24V of Smart Jig Voltage Power B D Smart Jig Voltage Switch 24V 24V 20V 20V 13 2V 18V 24V A21 5 19 Copyright 2018 LG Electronics Inc All rights reserved Only for training and service purpos...

Page 84: ...r Cable connector to the Muitl Gender JIG 24Pin connector 3 1 2 Check power board voltage Switch the product S W in JIG to LCD LCD MODEL Check the power voltage and switch 24V to the correct voltage Fix the LCD MODEL switch to 24V Smart JIG 4 A21 6 19 Copyright 2018 LG Electronics Inc All rights reserved Only for training and service purposes ...

Page 85: ...Diagnostic method 2 5 6 When the OK LED 24V 12V turns on Power Board is normal When the NG LED turns on the Power Board can be judged as defective A21 7 19 Copyright 2018 LG Electronics Inc All rights reserved Only for training and service purposes ...

Page 86: ... Switch the LCD MODEL S W to 24V by checking the power voltage Fix the LCD MODEL switch to 24V Smart JIG When the OK LED 24V 12V turns on Power Board is normal When the NG LED turns on the Power Board can be judged as defective A21 8 19 Copyright 2018 LG Electronics Inc All rights reserved Only for training and service purposes ...

Page 87: ...ch to 24V Smart JIG Disconnect the Main Board 24Pin Power Cable connector Connect the 24Pin Power Cable connector to the Muitl Gender JIG 24Pin connector When the OK LED 24V 12V turns on Power Board is normal A21 9 19 Copyright 2018 LG Electronics Inc All rights reserved Only for training and service purposes ...

Page 88: ... Board 24Pin Power Cable connector Connect the 24Pin Power Cable connector to the Muitl Gender JIG 24Pin connector When the OK LED 24V 12V turns on Power Board is normal When the NG LED turns on the Power Board can be judged as defective A21 10 19 Copyright 2018 LG Electronics Inc All rights reserved Only for training and service purposes ...

Page 89: ... Board 24Pin Power Cable connector Connect the 24Pin Power Cable connector to the Muitl Gender JIG 24Pin connector When the OK LED 24V 12V turns on Power Board is normal When the NG LED turns on the Power Board can be judged as defective A21 11 19 Copyright 2018 LG Electronics Inc All rights reserved Only for training and service purposes ...

Page 90: ...Muitl Gender JIG 28Pin connector Switch the LCD MODEL S W to 20V by checking the power voltage Fix the LCD MODEL switch to 20V Smart JIG When the OK LED 24V 12V turns on Power Board is normal When the NG LED turns on the Power Board can be judged as defective A21 12 19 Copyright 2018 LG Electronics Inc All rights reserved Only for training and service purposes ...

Page 91: ...l Gender JIG 28Pin connector Switch the LCD MODEL S W to 20V by checking the power voltage Fix the LCD MODEL switch to 20V Smart JIG When the OK LED 24V 12V turns on Power Board is normal When the NG LED turns on the Power Board can be judged as defective A21 13 19 Copyright 2018 LG Electronics Inc All rights reserved Only for training and service purposes ...

Page 92: ...ain Board 18Pin Power Cable connector Connect the 18Pin Power Cable connector to the Muitl Gender JIG 24Pin connector When the OK LED 24V 12V turns on Power Board is normal When the NG LED turns on the Power Board can be judged as defective A21 14 19 Copyright 2018 LG Electronics Inc All rights reserved Only for training and service purposes ...

Page 93: ...ain Board 28Pin Power Cable connector Connect the 28Pin Power Cable connector to the Muitl Gender JIG 28Pin connector When the OK 24V 12V LED turns on Power Board is normal When the NG LED turns on the Power Board can be judged as defective A21 15 19 Copyright 2018 LG Electronics Inc All rights reserved Only for training and service purposes ...

Page 94: ... Main Board 28Pin Power Cable connector Connect the 28Pin Power Cable connector to the Muitl Gender JIG 28Pin connector When the OK LED 24V 12V turns on Power Board is normal When the NG LED turns on the Power Board can be judged as defective A21 16 19 Copyright 2018 LG Electronics Inc All rights reserved Only for training and service purposes ...

Page 95: ...ain Board 12Pin Power Cable connector Connect the 12Pin Power Cable connector to the Muitl Gender JIG 12Pin connector When the OK LED 24V 12V turns on Power Board is normal When the NG LED turns on the Power Board can be judged as defective A21 17 19 Copyright 2018 LG Electronics Inc All rights reserved Only for training and service purposes ...

Page 96: ...n Board 12Pin Power Cable connector Connect the 12Pin Power Cable connector to the Muitl Gender JIG 24Pin connector When the OK LED 24V 12V turns on Power Board is normal When the NG LED turns on the Power Board can be judged as defective A21 18 19 Copyright 2018 LG Electronics Inc All rights reserved Only for training and service purposes ...

Page 97: ...n Board 28Pin Power Cable connector Connect the 28Pin Power Cable connector to the Muitl Gender JIG 28Pin connector When the OK LED 24V 12V turns on Power Board is normal When the NG LED turns on the Power Board can be judged as defective A21 19 19 Copyright 2018 LG Electronics Inc All rights reserved Only for training and service purposes ...

Page 98: ......

Search results

Summary of Contents for 55SK8550PUA

Reviews:

Related manuals for 55SK8550PUA

Brands by name

Popular brands

LG 55SK8550PUA, Service Manual

Search results

Summary of Contents for 55SK8550PUA

Reviews:

Related manuals for 55SK8550PUA

Brands by name

Popular brands