LG 55UM7450PVA Service Manual

Chassis ub93u

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LED TV

SERVICE MANUAL

CHASSIS : UB93U

MODEL : 55UM7400PTA

CAUTION

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

P/NO : MFL71443401 (1901-REV00)

55UM7450PVA

CONFIDENTIAL

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Summary of Contents for LG 55UM7450PVA

Page 1 LED TV SERVICE MANUAL CHASSIS : UB93U MODEL : 55UM7400PTA 55UM7450PVA CAUTION BEFORE SERVICING THE CHASSIS, READ THE SAFETY PRECAUTIONS IN THIS MANUAL. P/NO : MFL71443401 (1901-REV00) Copyright © 2019 LG Electronics Inc. All rights reserved. Only training and service purposes.
Page 2 SPECIFICATION ..................6 SOFTWARE UPDATE ................10 BLOCK DIAGRAM ................. 11 EXPLODED VIEW .................. 21 DISASSEMBLY GUIDE ................23 TROUBLE SHOOTING GUIDE ..........APPENDIX - 2 - Copyright © LG Electronics Inc. All rights reserved. Only training and service purposes.
Page 3: Safety Precautions
When the exposed metal has no return path to the chassis the reading must be infinite. An other abnormality exists that must be corrected before the receiver is returned to the customer. - 3 - Copyright © LG Electronics Inc. All rights reserved. Only 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. Only training and service purposes.
Page 6: Specification
DVI Audio, Component, AV 10 SPDIF out Optical Audio out Headphone out Antenna, HDMI1, HDMI2, HDMI3, HDMI4, USB1, USB2, USB3 Except UB93x 12 Ethernet Connect - 6 - Copyright © LG Electronics Inc. All rights reserved. Only training and service purposes.
Page 7: Component Input
33.75 79.2 HDTV 1080P 1920*1080 56.25 148.5 HDTV 1080P 1920*1080 67.43 59.94 148.35 HDTV 1080P 1920*1080 67.5 148.5 HDTV 1080P 1920*1080 112.5 UDTV 2160P - 7 - Copyright © LG Electronics Inc. All rights reserved. Only training and service purposes.
Page 8 8K Model Only. This will 7680*4320 131.87 29.97 1188 be added in USERGUIDE after 8K model develop- 7680*4320 1188 ment. 7680*4320 2376 7680*4320 263.74 59.94 2376 7680*4320 2376 - 8 - Copyright © LG Electronics Inc. All rights reserved. Only training and service purposes.
Page 9 8K Model Only. This will be 7680*4320 131.87 29.97 1188 added in USERGUIDE af- 7680*4320 1188 ter 8K model development. 7680*4320 2376 7680*4320 263.74 59.94 2376 7680*4320 2376 - 9 - Copyright © LG Electronics Inc. All rights reserved. Only training and service purposes.
Page 10 (7) Click [Yes] : TV will be DC OFF → ON. and Tool Option. (8) After TV turned on, Check the updated SW Version and Tool Option. - 10 - Copyright © LG Electronics Inc. All rights reserved. Only training and service purposes.
Page 13 Main SOC Panel 3840x2160@60p VX1_MSE [PAD_GPIO19] AGP_CTL [ PAD_GPIO20] Vx1 8Lane 51P [ PAD_MOD_TX_P00~07] LOCKAn [PAD_MOD_TX_P12(LVA3- )] HTPDAn [PAD_MOD_TX_N12(LVA3+)] I2C_SCL6/SDA6 [PAD_GPIO30SCK4] DATA_FORMAT_0/1 [PAD_GPIO31SDA4] [PAD_GPIO23] [PAD_GPIO24] - 13 - Copyright © LG Electronics Inc. All rights reserved. Only training and service purposes.
Page 21 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. - 21 - Copyright © LG Electronics Inc. All rights reserved. Only training and service purposes.
Page 23 (3) Rear AV Screw (③) Assembly * Do not wear items that may damage the appearance of the product * SCREW TORQUE : 5 ~ 7Kgf.cm - 23 - Copyright © LG Electronics Inc. All rights reserved. Only training and service purposes.
Page 24 (2) Insert the finger of the back cover bottom section triangle hole and disassemble it. * Do not wear items that may damage the appearance of the product. * SCREW TORQUE : 5 ~ 7Kgf.cm - 24 - Copyright © LG Electronics Inc. All rights reserved. Only training and service purposes.
Page 25 ■ Step 5. Case Top Screw disassemble (side screw) and Case Top disassemble * Screw down 7 EA * Hook top 6ea / side L 5 EA / side R 5 EA - 25 - Copyright © LG Electronics Inc. All rights reserved. Only training and service purposes.
Page 26 ■ Step 8. Optical Sheet disassemble (Prism up, Prism down, DP) ■ Step 9. DPS, LED Fixer disassemble & Reflector Sheet disassemble. *rotate DPS (9 EA) *push LED fixer in back (4 EA) - 26 - Copyright © LG Electronics Inc. All rights reserved. Only training and service purposes.
Page 27 (2) Press the LED Array on the surface of Cover Bottom. (3) Connect the CNT to the LED Array. * Finish the Attached LED Array (4 EA) - 27 - Copyright © LG Electronics Inc. All rights reserved. Only training and service purposes.
Page 29 E. Noise Circuit noise, mechanical noise F. Exterior error Exterior defect First of all, Check whether there is SVC Bulletin in GSCS System for these model. Copyright © 2019 LG Electronics. Inc. All rights reserved. Only for training and service purposes...
Page 30 ☞A4 & A2 Always check & record S/W Version and White Replace Main Board Re-enter White Balance value Balance value before replacing the Main Board Copyright © 2019 LG Electronics. Inc. All rights reserved. Only for training and service purposes...
Page 31 ☞A18 Check various Check and No Video/ Normal voltages of Power replace No audio voltage? Board (13.2V…) MAIN B/D Replace Power Board and repair parts Copyright © 2019 LG Electronics. Inc. All rights reserved. Only for training and service purposes...
Page 32 1. Reconnection 2. Install Booster S/W Upgrade Contact with signal distributor Normal or broadcaster (Cable or Air) Picture? Normal Picture? Replace Main B/D Close Close Copyright © 2019 LG Electronics. Inc. All rights reserved. Only for training and service purposes...
Page 33 Replace Main/T-con B/D error cable normal Request repair for external device/cable Check external External HDMI device and Replace Main/T-con B/D device/ Cable error cable normal Copyright © 2019 LG Electronics. Inc. All rights reserved. Only for training and service purposes...
Page 34 Replace screen? HDMI/ Screen (Check normal operation of Main /T-con normal? External Input, Component, RGB and HDMI/DVI by connecting Jig, pattern Generator ,Set-top Box etc. Copyright © 2019 LG Electronics. Inc. All rights reserved. Only for training and service purposes...
Page 35: Power Error
Measure voltage of each output of Power B/D Normal? Normal Replace Main B/D voltage? Normal Check ST-BY 3.5V Close voltage? ☞A18 Replace Power B/D Replace Power Copyright © 2019 LG Electronics. Inc. All rights reserved. Only for training and service purposes...
Page 36 Replace Main B/D Abnormal Check for all 3- phase Replace Power B/D Abnormal power out Fix A/C cord & Outlet and check each 3 phase out Copyright © 2019 LG Electronics. Inc. All rights reserved. Only for training and service purposes...
Page 37 Reboot by SW down load function UNKNOWN No meaning (same as initial value) COMP_END OLED threshold voltage degradation(Compensation) completes. PNWASHDONE Power off by panel noise wash function complited. (OLED) Copyright © 2019 LG Electronics. Inc. All rights reserved. Only for training and service purposes...
Page 38 13.2V of Power Screen normal voltage Speaker off Board Cancel OFF Replace Power Board and repair parts Check Replace MAIN Board Disconnection Speaker disconnection Replace Speaker Copyright © 2019 LG Electronics. Inc. All rights reserved. Only for training and service purposes...
Page 39 (In case of Connect and check Normal External Input other external audio? signal error) device Check and fix external device Check and fix external device Copyright © 2019 LG Electronics. Inc. All rights reserved. Only for training and service purposes...
Page 40: Function Error
Replace Main B/D (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 Copyright © 2019 LG Electronics. Inc. All rights reserved. Only for training and service purposes...
Page 41 RF Receiver ver Close is “00.00”? Replace MR19 Close Change the RF Receiver assy * If you conduct the loop at 3times, change the M4. Copyright © 2019 LG Electronics. Inc. All rights reserved. Only for training and service purposes...
Page 42 Voltage? Main B/D INSTART menu “NG”? ☞A24 Close Check & Repair Wifi cable connection ☞A4 Wi-Fi Mac value Close is “NG”? Change the Wifi assy Copyright © 2019 LG Electronics. Inc. All rights reserved. Only for training and service purposes...
Page 43 Recognition error - S/W Version HDMI/ Check and fix DVI, Optical Replace Main B/D Fix in Recognition external device/cable accordance error with technical information Copyright © 2019 LG Electronics. Inc. All rights reserved. Only for training and service purposes...
Page 44 “Part related to nose” in the Owner’s then proceed as shown in the solution manual Manual. (For models without any fix information, provide the description) Copyright © 2019 LG Electronics. Inc. All rights reserved. Only for training and service purposes...
Page 45 Revised date Zoom part with Module Replace module exterior damage damage Cabinet Replace cabinet damage Remote control Replace remote control damage Stand Replace stand dent Copyright © 2019 LG Electronics. Inc. All rights reserved. Only for training and service purposes...
Page 46 Exchange Module (1) ~ (3) Inverter/ Module A-8/11 A-9/11 ~ Only using Exchange T-Con (1) ~ (2) T-con model A-10/11 Exchange Power Board(PSU) A-11/11 Continue to the next page Copyright © 2019 LG Electronics. Inc. All rights reserved. Only for training and service purposes...
Page 47 Check items after Main B/D replacement E. Etc Adjustment Test pattern - ADJ Key How to use JIG (Power B/D Diagnostic Smart Jig Multi Gender) Copyright © 2019 LG Electronics. Inc. All rights reserved. Only for training and service purposes...
Page 48 Check LCD back light with naked eye Content date After turning on the power and disassembling the case, check with the naked eye, whether you can see light from locations. Copyright © 2019 LG Electronics. Inc. All rights reserved. Only for training and service purposes...
Page 49 2. Enter into White Balance. 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 © 2019 LG Electronics. Inc. All rights reserved. Only for training and service purposes...
Page 50 All Setting  Programmes Programme Tuning & Settings  Manual Tuning All Settings When the signal is strong, use the attenuator (-10dB, - 15dB, -20dB etc.) Copyright © 2019 LG Electronics. Inc. All rights reserved. Only for training and service purposes...
Page 51 Version checking method Content date <ALL MODELS> 1. Checking method for remote control for adjustment Version Press the IN-START with the remote control for adjustment Copyright © 2019 LG Electronics. Inc. All rights reserved. Only for training and service purposes...
Page 52 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. Copyright © 2019 LG Electronics. Inc. All rights reserved. Only for training and service purposes...
Page 53 Revised Content connection diagram (1) date <ALL MODELS> As the part connecting to the external input, check the screen condition by signal Copyright © 2019 LG Electronics. Inc. All rights reserved. Only for training and service purposes...
Page 54 A. Video error_Color error symptom date Revised Content Check Link Cable(EPI) reconnection condition date Check the contact condition of the Link Cable, especially dust or mis insertion. Copyright © 2019 LG Electronics. Inc. All rights reserved. Only for training and service purposes...
Page 55 Screen darkness to disconnection of the FFC cable pin. G color transient due to poor FFC cable CABLE G Color Excessive connection A - 1/11 Copyright © 2019 LG Electronics. Inc. All rights reserved. Only for training and service purposes...
Page 56 CABLE Color spread FFC connection problem CABLE Color spread FFC connection problem Due to foreign substance within CABLE Screen stop FFC PIN A - 2/11 Copyright © 2019 LG Electronics. Inc. All rights reserved. Only for training and service purposes...
Page 57 Main IC problem Main Dark picture Dark left-side screen Top/bottom screen part Main Broken picture Picture problem due to tuner Inner side quality problem A - 3/11 Copyright © 2019 LG Electronics. Inc. All rights reserved. Only for training and service purposes...
Page 58 Screen spread Screen corner appears blurry Main Color Spread Color spread on the screen Main Blurry Screen Blurry picture on the screen A - 4/11 Copyright © 2019 LG Electronics. Inc. All rights reserved. Only for training and service purposes...
Page 59 Screen picture spread problem Screen problem No problem at the initial stage. Right-side Main During Heat run, right-side picture picture problem problem A - 5/11 Copyright © 2019 LG Electronics. Inc. All rights reserved. Only for training and service purposes...
Page 60 BLU internal foreign matter inflow MODULE Internal matter 6 block image broken MODULE Image broken MODULE Image broken Screen sync signal broken A - 6/11 Copyright © 2019 LG Electronics. Inc. All rights reserved. Only for training and service purposes...
Page 61 BLU Vertical spreading on cube screen in no MODULE Vertical smear signal MODULE Over color Screen contour part brightly Over color A - 7/11 Copyright © 2019 LG Electronics. Inc. All rights reserved. Only for training and service purposes...
Page 62 Center of the screen 1 block dark MODULE Screen darkness MODULE Vertical bar Center Vertical Bar Darkness at the MODULE bottom of the MODULE internal BLU breakage screen A - 8/11 Copyright © 2019 LG Electronics. Inc. All rights reserved. Only for training and service purposes...
Page 64 The entire screen is dark and bit noise T-CON Image Broken occurs The entire screen is dark and bit noise T-CON Image Broken occurs A - 10/11 Copyright © 2019 LG Electronics. Inc. All rights reserved. Only for training and service purposes...
Page 66 Established 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 Copyright © 2019 LG Electronics. Inc. All rights reserved. Only for training and service purposes...
Page 67 5. LED voltage Check : P801, Pin 1-7 Picture Condition : VIVID (Back light 100) SK100 (AC input) 175.5V 214.5V all condition meets, Power Board OK. Copyright © 2019 LG Electronics. Inc. All rights reserved. Only for training and service purposes...
Page 68 POWER OFF MODE checking method date <ALL MODELS> Entry method 1. Press the IN-START button of the remote control for adjustment. 2. Check the entry into adjustment item 3. Copyright © 2019 LG Electronics. Inc. All rights reserved. Only for training and service purposes...
Page 69: 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 © 2019 LG Electronics. Inc. All rights reserved. Only for training and service purposes...
Page 70 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. Copyright © 2019 LG Electronics. Inc. All rights reserved. Only for training and service purposes...
Page 71 2. Check the standby 3.5V on the terminal 6 pin. (③) 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. Copyright © 2019 LG Electronics. Inc. All rights reserved. Only for training and service purposes...
Page 72 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. Copyright © 2019 LG Electronics. Inc. All rights reserved. Only for training and service purposes...
Page 73 Standard Repair Process Detail Technical Manual Error Established E. Etc symptom date Revised Content How to use the Service remote control date 1. How to access the remote control Copyright © 2019 LG Electronics. Inc. All rights reserved. Only for training and service purposes...
Page 74 Digital EYE function ON/OFF For some Model, access to the Test Pattern TILT Used for screen tilting change (Access to the old PDP control mode) Copyright © 2019 LG Electronics. Inc. All rights reserved. Only for training and service purposes...
Page 75 Connects to external input 1,2,3 COMP1,2 (Added function) Connects to Component 1,2 HDMI1,2,3,4 Connects to HDMI 1,2,3,4 (Add function) DVI (Add function) Connects to DVI Copyright © 2019 LG Electronics. Inc. All rights reserved. Only for training and service purposes...
Page 76 - Record the R, G, B (GAIN, Cut) value of the color temperature before main board replacement. After replacing the main board, key in the recorded value. Copyright © 2019 LG Electronics. Inc. All rights reserved. Only for training and service purposes...
Page 77 You can view 9 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!) Copyright © 2019 LG Electronics. Inc. All rights reserved. Only for training and service purposes...
Page 78 Smart JIG Power Diagnosis Muitl Gender Guide (P/N : RAD32507801) (P/N : RAD33187801) A 29 (1/19) Copyright © 2019 LG Electronics. Inc. All rights reserved. Only for training and service purposes...
Page 79: Main Board
24 Marking Check UK74,UK75 28Pin 28Pin 12Pin 12Pin 28Pin UK77,UK78 Cable Connection SK79 Includes 49UJ63 SM86 16/18Y/19Y 16Y/17Y 17Y/18Y 16Y/17Y/18Y/19Y (UH) (UH/SJ) (SJ/UJ/UK/SK) (UH/UK/UM A29 (2/19) (LH/LJ/LK/LM) Copyright © 2019 LG Electronics. Inc. All rights reserved. Only for training and service purposes...
Page 80 LJ61/LJ68, LJ55/LJ58 SK80/SK85/SK95 UK78/UK75/UK77/SK79 ‘18 UK63/UK64/UK65/UK68/UK7050 LK57, 32/43/49LK54, 32LK61/62, 43/49LK61 ‘18 OLED B8, C8, E8, G8, W8 SM86 ‘19 UM73/UM74/UM76/UM79 LM63 ‘19 OLED C9/E9 A29 (3/19) Copyright © 2019 LG Electronics. Inc. All rights reserved. Only for training and service purposes...
Page 81 “A: 2013 LCD POWER” 2014 ▶ Connect the Muiti Gender to the connector (black) as shown in picture 2 of the Smart JIG. A29 (4/19) Copyright © 2019 LG Electronics. Inc. All rights reserved. Only for training and service purposes...
Page 82 - 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 13.2V/18V A29 (5/19) Copyright © 2019 LG Electronics. Inc. All rights reserved. Only for training and service purposes...
Page 83 ▶ Disconnect the Main Board 24Pin Power Cable connector. ▶ Connect the 24Pin Power Cable connector to the Muitl Gender JIG 24Pin connector A29 (6/19) Copyright © 2019 LG Electronics. Inc. All rights reserved. Only for training and service purposes...
Page 84 ▶ 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. A29 (7/19) Copyright © 2019 LG Electronics. Inc. All rights reserved. Only for training and service purposes...
Page 85 ▶ 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. A29 (8/19) Copyright © 2019 LG Electronics. Inc. All rights reserved. Only for training and service purposes...
Page 86 ▶ When the OK LED(24V,12V) turns on, Power Board is normal. ▶ Connect the 24Pin Power Cable connector to the Muitl Gender JIG 24Pin connector A29 (9/19) Copyright © 2019 LG Electronics. Inc. All rights reserved. Only for training and service purposes...
Page 87 ▶ Connect the 24Pin Power Cable connector to the Muitl Gender JIG 24Pin connector ▶ When the NG LED turns on, the Power Board A29 (10/19) can be judged as defective. Copyright © 2019 LG Electronics. Inc. All rights reserved. Only for training and service purposes...
Page 88 ▶ Connect the 24Pin Power Cable connector to the Muitl Gender JIG 24Pin connector ▶ When the NG LED turns on, the Power Board A29 (11/19) can be judged as defective. Copyright © 2019 LG Electronics. Inc. All rights reserved. Only for training and service purposes...
Page 89 ▶ When the NG LED turns on, the Power Board ▶ Fix the LCD MODEL switch to 20V.(Smart JIG) A29 (12/19) can be judged as defective. Copyright © 2019 LG Electronics. Inc. All rights reserved. Only for training and service purposes...
Page 90 ▶ When the NG LED turns on, the Power Board ▶ Fix the LCD MODEL switch to 20V.(Smart JIG) A29 (13/19) can be judged as defective. Copyright © 2019 LG Electronics. Inc. All rights reserved. Only for training and service purposes...
Page 91 ▶ Connect the 18Pin Power Cable connector to the Muitl Gender JIG 24Pin connector ▶ When the NG LED turns on, the Power Board A29 (14/19) can be judged as defective. Copyright © 2019 LG Electronics. Inc. All rights reserved. Only for training and service purposes...
Page 92 ▶ Connect the 28Pin Power Cable connector to the Muitl Gender JIG 28Pin connector ▶ When the NG LED turns on, the Power Board A29 (15/19) can be judged as defective. Copyright © 2019 LG Electronics. Inc. All rights reserved. Only for training and service purposes...
Page 93 ▶ Connect the 28Pin Power Cable connector to the Muitl Gender JIG 28Pin connector ▶ When the NG LED turns on, the Power Board A29 (16/19) can be judged as defective. Copyright © 2019 LG Electronics. Inc. All rights reserved. Only for training and service purposes...
Page 94 ▶ Connect the 12Pin Power Cable connector to the Muitl Gender JIG 12Pin connector ▶ When the NG LED turns on, the Power Board A29 (17/19) can be judged as defective. Copyright © 2019 LG Electronics. Inc. All rights reserved. Only for training and service purposes...
Page 95 ▶ Connect the 12Pin Power Cable connector to the Muitl Gender JIG 24Pin connector ▶ When the NG LED turns on, the Power Board A29 (18/19) can be judged as defective. Copyright © 2019 LG Electronics. Inc. All rights reserved. Only for training and service purposes...
Page 96 ▶ Connect the 28Pin Power Cable connector to the Muitl Gender JIG 28Pin connector ▶ When the NG LED turns on, the Power Board A29 (19/19) can be judged as defective. Copyright © 2019 LG Electronics. Inc. All rights reserved. Only for training and service purposes...

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55um7400pta

LG 55UM7450PVA Service Manual

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Summary of Contents for LG 55UM7450PVA

Page 3: Safety Precautions

Page 4: Servicing Precautions

Page 6: Specification

Page 7: Component Input

Page 11: Block Diagram

Page 28: Troubleshooting Guide

Page 35: Power Error

Page 40: Function Error

Page 69: Checking Method

Page 79: Main Board

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