LG 55SJ850 Series Service Manual

Hide thumbs

Table of Contents

Quick Links

Download this manual

LED TV

SERVICE MANUAL

CHASSIS : UD71H

MODEL : 55SJ850*

CAUTION

BEFORE SERVICING THE CHASSIS, READ THE SAFETY PRECAUTIONS IN THIS MANUAL.

P/NO : MFL69780301 (1702-REV00)

Internal Use Only

55SJ850*-ZA

Table of Contents

Need help?

Do you have a question about the 55SJ850 Series and is the answer not in the manual?

Questions and answers

Summary of Contents for LG 55SJ850 Series

Page 1 Internal Use Only LED TV LED TV SERVICE MANUAL SERVICE MANUAL CHASSIS : UD71H MODEL : 55SJ850* 55SJ850*-ZA CAUTION BEFORE SERVICING THE CHASSIS, READ THE SAFETY PRECAUTIONS IN THIS MANUAL. P/NO : MFL69780301 (1702-REV00)
Page 2 BLOCK DIAGRAM .................. 11 EXPLODED VIEW .................. 18 DISASSEMBLY GUIDE ................19 TROUBLE SHOOTING GUIDE ..........APPENDIX OVERVIEW FOR 55SJ85 ............APPENDIX - 2 - Copyright © LG Electronics Inc. All rights reserved. LGE Internal Use Only Only for training and service purposes...
Page 3: Safety Precautions
An other abnormality exists that must be corrected before the receiver is returned to the customer. - 3 - Copyright © LG Electronics Inc. All rights reserved. LGE Internal Use Only Only for training and service purposes...
Page 5 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. - 5 - Copyright © LG Electronics Inc. All rights reserved. LGE Internal Use Only Only for training and service purposes...
Page 6: Specification
SAT10&7 68.5E, INTELSAT15 85.2E, INTELSAT1R 50.0W, INTEL- SAT903 33.5W, INTELSAT904 60.0E, NILESAT 7.0W, NSS12 57.0E, THOR 0.8W, TURKSAT 42.0E,YAMAL201 90.0E, OTHER - 6 - Copyright © LG Electronics Inc. All rights reserved. LGE Internal Use Only Only for training and service purposes...
Page 7 SPDIF out USB (3EA) EMF, For SVC (download) Ethernet Connect(1EA) Ethernet Connect STP cable. PCMCIA Card slot (1EA) PCMCIA slot - 7 - Copyright © LG Electronics Inc. All rights reserved. LGE Internal Use Only Only for training and service purposes...
Page 8 UDTV 2160P 4096*2160 56.25 25.00 297.00 UDTV 2160P 4096*2160 61.43 29.97 296.703 UDTV 2160P 4096*2160 67.50 30.00 297.00 UDTV 2160P - 8 - Copyright © LG Electronics Inc. All rights reserved. LGE Internal Use Only Only for training and service purposes...
Page 9 UDTV 2160P 3840*2160 67.50 30.00 297.00 UDTV 2160P 4096*2160 53.95 23.97 296.70 UDTV 2160P 4096*2160 54.00 24.00 297.00 UDTV 2160P - 9 - Copyright © LG Electronics Inc. All rights reserved. LGE Internal Use Only Only for training and service purposes...
Page 10: Software Update
(7) Click [Yes] : TV will be DC OFF -> ON (8) After TV turned on, Check the updated SW Version and Tool Option. - 10 - Copyright © LG Electronics Inc. All rights reserved. LGE Internal Use Only Only for training and service purposes...
Page 18: Exploded View
Shock, Fire, or other Hazards. Do not modify the original design without permission of manufacturer. - 18 - Copyright © LG Electronics Inc. All rights reserved. LGE Internal Use Only Only for training and service purposes...
Page 19: Disassembly Guide
1. After Screw Disassemble, please remove B/C from Module -Screw : 16 ea, Latch : 4 ea Disassemble latch (4ea) 2. Detach Tape Detach tape Detach tape - 19 - Copyright © LG Electronics Inc. All rights reserved. LGE Internal Use Only Only for training and service purposes...
Page 20 4. IR assy, WiFi PCB assy disassembly Disassemble screw (1ea) and Remove cable from speaker holder Disassemble Latch (2ea) - 20 - Copyright © LG Electronics Inc. All rights reserved. LGE Internal Use Only Only for training and service purposes...
Page 21: Speaker Disassembly
5. Screw disassembly -Screw : 10 ea 6. Speaker disassembly - 21 - Copyright © LG Electronics Inc. All rights reserved. LGE Internal Use Only Only for training and service purposes...
Page 22 7. Screw disassembly -Screw : 4 ea 8. Screw disassembly -Screw : 4 ea - 22 - Copyright © LG Electronics Inc. All rights reserved. LGE Internal Use Only Only for training and service purposes...
Page 24 Circuit noise, mechanical noise F. Exterior error Exterior defect First of all, Check whether there is SVC Bulletin in GSCS System for these model. LGE Internal Use Only Copyright 2017 LG Electronics Inc. All rights reserved. Only for training and service purposes...
Page 25 Always check & record S/W Version and White Replace Main Board Re-enter White Balance value Balance value before replacing the Main Board LGE Internal Use Only Copyright 2017 LG Electronics Inc. All rights reserved. Only for training and service purposes...
Page 26 Check and Normal voltages of Power No Video/ replace voltage? Board (20V, 13.2V…) No audio MAIN B/D Replace Power Board and repair parts LGE Internal Use Only Copyright 2017 LG Electronics Inc. All rights reserved. Only for training and service purposes...
Page 27 2. Install Booster S/W Upgrade Normal Contact with signal distributor or broadcaster (Cable or Air) Picture? Normal Picture? Replace Main B/D Close Close LGE Internal Use Only Copyright 2017 LG Electronics Inc. All rights reserved. Only for training and service purposes...
Page 28 Request repair for external device/cable Check external External device device and Replace Main B/D HDMI /Cable error cable normal LGE Internal Use Only Copyright 2017 LG Electronics Inc. All rights reserved. Only for training and service purposes...
Page 29 Screen (Check normal operation of Main B/D normal? External Input, Component, RGB and HDMI/DVI by connecting Jig, pattern Generator ,Set-top Box etc. LGE Internal Use Only Copyright 2017 LG Electronics Inc. All rights reserved. Only for training and service purposes...
Page 30: Power Error
Measure voltage of each output of Power B/D Normal? Normal Replace Main B/D voltage? Close Normal Check ST-BY 3.5V voltage? ☞A18 Replace Power B/D Replace Power B/D LGE Internal Use Only Copyright 2017 LG Electronics Inc. All rights reserved. Only for training and service purposes...
Page 31 Power off by unknown status except listed case "POWEROFF_ABNORMAL1" Power off by abnormal status except CPU trouble Abnormal "POWEROFF_CPUABNORMAL" Power off by CPU Abnormal LGE Internal Use Only Copyright 2017 LG Electronics Inc. All rights reserved. Only for training and service purposes...
Page 32 Screen normal voltage Speaker off Board Cancel OFF Replace Power Board and repair parts Check Replace MAIN Board Disconnection Speaker disconnection Replace Speaker LGE Internal Use Only Copyright 2017 LG Electronics Inc. All rights reserved. Only for training and service purposes...
Page 33 Connect and check Normal External Input other external audio? signal error) device Check and fix external device Check and fix external device LGE Internal Use Only Copyright 2017 LG Electronics Inc. All rights reserved. Only for training and service purposes...
Page 34: Function Error
(Power B/D don’t have problem) If R/C operate, Normal Close operating? Explain the customer cause is interference from light in room. Replace R/C LGE Internal Use Only Copyright 2017 LG Electronics Inc. All rights reserved. Only for training and service purposes...
Page 35 Down load the Firmware * If you conduct the loop at 3times, change the M4. * INSTART MENU14.RF Remocon Test3. Firmware download LGE Internal Use Only Copyright 2017 LG Electronics Inc. All rights reserved. Only for training and service purposes...
Page 36 1pin Main B/D ☞A24 Close Check & Repair Wifi cable connection ☞A4 Wi-Fi Mac value Close is “NG”? Change the Wifi assy LGE Internal Use Only Copyright 2017 LG Electronics Inc. All rights reserved. Only for training and service purposes...
Page 37 - S/W Version HDMI/ Check and fix DVI, Optical Replace Main B/D Fix in external device/cable Recognition error accordance with technical information LGE Internal Use Only Copyright 2017 LG Electronics Inc. All rights reserved. Only for training and service purposes...
Page 38 ※ Describe the basis of the description (For models without any fix information, in “Part related to nose” in the Owner’s provide the description) Manual. LGE Internal Use Only Copyright 2017 LG Electronics Inc. All rights reserved. Only for training and service purposes...
Page 39 Zoom part with Module Replace module exterior damage damage Cabinet Replace cabinet damage Remote control Replace remote control damage Stand Replace stand dent LGE Internal Use Only Copyright 2017 LG Electronics Inc. All rights reserved. Only for training and service purposes...
Page 40 Defected Type caused by T-Con/ Exchange Power Board (PSU) A-3/5 Inverter/ Module Exchange Module (1) A-4/5 Exchange Module (2) A-5/5 Continue to the next page LGE Internal Use Only Copyright 2017 LG Electronics Inc. All rights reserved. Only for training and service purposes...
Page 41 Voltage and speaker checking method when there is no audio Remote control operation checking method D. Function error Motion Remote operation checking method LGE Internal Use Only Copyright 2017 LG Electronics Inc. All rights reserved. Only for training and service purposes...
Page 42 After turning on the power and disassembling the case, check with the naked eye, whether you can see light from locations. LGE Internal Use Only Copyright 2017 LG Electronics Inc. All rights reserved. Only for training and service purposes...
Page 43 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. LGE Internal Use Only Copyright 2017 LG Electronics Inc. All rights reserved. Only for training and service purposes...
Page 44 <ALL MODELS>  Advanced Channels Channel Tuning Manual Tuning When the signal is strong, use the attenuator (-10dB, - 15dB, -20dB etc.) LGE Internal Use Only Copyright 2017 LG Electronics Inc. All rights reserved. Only for training and service purposes...
Page 45 Content date <ALL MODELS> 1. Checking method for remote control for adjustment Version Press the IN-START with the remote control for adjustment LGE Internal Use Only Copyright 2017 LG Electronics Inc. All rights reserved. Only for training and service purposes...
Page 46 1. Check the 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. LGE Internal Use Only Copyright 2017 LG Electronics Inc. All rights reserved. Only for training and service purposes...
Page 47 Revised Connection diagram (1) Content date <ALL MODELS> As the part connecting to the external input, check the screen condition by signal LGE Internal Use Only Copyright 2017 LG Electronics Inc. All rights reserved. Only for training and service purposes...
Page 48 Content Check Link Cable(VX1) reconnection condition date <ALL MODELS> Check the contact condition of the Link Cable, especially dust or mis insertion. LGE Internal Use Only Copyright 2017 LG Electronics Inc. All rights reserved. Only for training and service purposes...
Page 49 You can view 6 types of patterns using the ADJ 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!) LGE Internal Use Only Copyright 2017 LG Electronics Inc. All rights reserved. Only for training and service purposes...
Page 50 Solder defect, CNT Broken Solder defect, CNT Broken T-Con Defect, CNT Broken Abnormal Power Section Solder defect, Short/Crack Solder defect, Short/Crack A - 1/5 LGE Internal Use Only Copyright 2017 LG Electronics Inc. All rights reserved. Only for training and service purposes...
Page 51 Abnormal Power Section Solder defect, Short/Crack Abnormal Display Fuse Open, Abnormal power section Solder defect, Short/Crack Noise GRADATION GRADATION A - 2/5 LGE Internal Use Only Copyright 2017 LG Electronics Inc. All rights reserved. Only for training and service purposes...
Page 52 Appendix : Exchange Power Board (PSU) No Light Dim Light Dim Light Dim Light No picture/Sound Ok A - 3/5 LGE Internal Use Only Copyright 2017 LG Electronics Inc. All rights reserved. Only for training and service purposes...
Page 53 Appendix : Exchange the Module (1) Press damage Press damage Press damage Crosstalk Crosstalk Un-repairable Cases In this case please exchange the module. A - 4/5 LGE Internal Use Only Copyright 2017 LG Electronics Inc. All rights reserved. Only for training and service purposes...
Page 54 Un-repairable Cases In this case please exchange the module. Horizontal Block Gate TAB IC Defect Gate TAB IC Defect A - 5/5 LGE Internal Use Only Copyright 2017 LG Electronics Inc. All rights reserved. Only for training and service purposes...
Page 55 B. Power error _No power symptom date Revised Content Check front Power Indicator date ST-BY condition: On or Off Power ON condition: Turn Off LGE Internal Use Only Copyright 2017 LG Electronics Inc. All rights reserved. Only for training and service purposes...
Page 56 Values Symbol Unit Forward Voltage 65SJ 118.8 127.6 136.4 Check the DC 13.2V line for ST-BY Voltage 60SJ 55SJ 91.8 98.6 105.4 LGE Internal Use Only Copyright 2017 LG Electronics Inc. All rights reserved. Only for training and service purposes...
Page 57 <ALL MODELS> Entry method 1. Press the IN-START button of the remote control for adjustment 2. Check the entry into adjustment item 3 LGE Internal Use Only Copyright 2017 LG Electronics Inc. All rights reserved. Only for training and service purposes...
Page 58: 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 LGE Internal Use Only Copyright 2017 LG Electronics Inc. All rights reserved. Only for training and service purposes...
Page 59 3.Connect the tester RX1 to the speaker terminal and if you hear the Chik Chik sound when you touch the GND and output terminal, the speaker is normal. LGE Internal Use Only Copyright 2017 LG Electronics Inc. All rights reserved. Only for training and service purposes...
Page 60 3.AS checking the Pre-Amp(IR LED light) , the power is in ON condition, an Analog Tester needle should move slowly, otherwise, it’s defective. LGE Internal Use Only Copyright 2017 LG Electronics Inc. All rights reserved. Only for training and service purposes...
Page 61 Checking order to check motion remote/wifi KEY1 Checking order 1.Check BT/Wifi cable condition between BT/Wifi assy & Main board. 2.Check the 3.5V on the terminal 22 LGE Internal Use Only Copyright 2017 LG Electronics Inc. All rights reserved. Only for training and service purposes...

This manual is also suitable for:

55sj850 za series

LG 55SJ850 Series Service Manual

Quick Links

Need help?

Questions and answers

Summary of Contents for LG 55SJ850 Series

Page 3: Safety Precautions

Page 4: Servicing Precautions

Page 6: Specification

Page 10: Software Update

Page 11: Block Diagram

Page 13: Video & Audio In/Out

Page 18: Exploded View

Page 19: Disassembly Guide

Page 21: Speaker Disassembly

Page 23: Troubleshooting Guide

Page 30: Power Error

Page 34: Function Error

Page 58: Checking Method

This manual is also suitable for:

LG 55SJ850 Series Service Manual

Quick Links

Need help?

Questions and answers

Subscribe to Our Youtube Channel

Related Manuals for LG 55SJ850 Series

Summary of Contents for LG 55SJ850 Series

This manual is also suitable for:

Table of Contents