LG Electronics 37LN54**-Z* C. Audio error , LCD TV

Copyright © 2013 LG Electronics. Inc. All rights reserved.

Only for training and service purposes LGE Internal Use Only

→ abnormal audio/discontinuation/noise is same after “Check input signal” compared to No audio

C. Audio error

Wrecked audio/ discontinuation/noise

Wrecked audio/

Discontinuation/

Noise for

all audio

Check and replace

speaker and

connector

Wrecked audio/

Discontinuation/

Noise only

for D-TV

Wrecked audio/

Discontinuation/

Noise only

for Analog

Wrecked audio/

Discontinuation/

Noise only

for External 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 (24V)

Replace Main B/D

(In case of External

Input signal error)

Check and fix

external device

Replace Main B/D

N

End

Established

date

Revised date 10/14

LCD TV Error

symptom

Standard Repair Process

☞A16

2013. 01 .09

Contents

Main Page SAFETY PRECAUTIONS IMPORTANT SAFETY NOTICE General Guidance Before returning the receiver to the customer, Leakage Current Cold Check(Antenna Cold Check) SERVICING PRECAUTIONS Page SPECIFICATION 1. Application range 2. Requirement for Test 3. Test method 4. Model General Specification Page 5. Video resolutions (2D) 5.1. Component Input (Y, CB/PB, CR/PR) 5.2. HDMI Input(PC/DTV) 6. Video resolutions (3D) 6.1. HDMI Input 6.2. RF 3D Input(DTV) 6.3. USB Input 6.4. DLNA Input 6.5. 3D Input mode ADJUSTMENT INSTRUCTION 1. Application Range 2. Designation 3. Main PCB check process * Boot file Download 3.1. ADC Process 3.2. EDID Download 3.3. EDID data 3.4 Function Check 4. Total Assembly line process 4.1. White Balance adjustment * Auto-control interface and directions * Manual W/B process using adjust Remote control. 4.2. 3D function test 4.3. IR emitter inspection 4.4. MHL Test 4.5. Outgoing condition Configuration 5. HI-POT Test 5.1. HI-POT auto-check preparation 5.2. HI-POT auto-check 5.3. Checkpoint 6. Model name & Serial number D/L 7. MAC Address & CI+ key download 7.1 MAC Address SET PC 7.1.1 Equipment & Condition 7.1.2 Download method R ear Side - LN54*S, LN54*R LN54*6, LN54*5, LA61*S, LA61*6 Audio AMP STA380BWF S7LR-M (LGE2121 -MS) R ear 2. [LD31B] DVB-T2/C/S2(2D_3D) Side - LN54*V, LN54*U, LA61*V S7LR-M (LGE2121 -MS) Rear 3. [LD36B] DVB-T/C(2D) Side CI Slot Buffer EXPLODED VIEW FILRE AND ELECTRICAL SHOCK HAZARDS, WHEN SERVICING IF IS AR101 SYM.A I2C Internal demod out SYM.C STby 3.5V COMP2 CVBS In/OUT I2S_I/F PANEL_POWER +2.5V_Normal S7LR core 1.15V volt +3.5V_ST --> 3.375V --> 3.46V FROM LIPS & POWER B/D +3.3V_Normal IR/LED and Control USB (SIDE) FILRE AND ELECTRICAL SHOCK HAZARDS, WHEN SERVICING IF IS +3.3V_Normal /MHL_OCP_DET 2012/07/12 HDMI_R1_S1 8 HDMI (REAR 1 / SIDE 1 MHL) FILRE AND ELECTRICAL SHOCK HAZARDS, WHEN SERVICING IF IS NC4_S7LRM SPDIF 12/06/12 10 SPDIF FILRE AND ELECTRICAL SHOCK HAZARDS, WHEN SERVICING IF IS IC1201 IC1201-*5 NT5CB128M16FP-DI IC1202-*5 Serial Flash for SPI boot(OS) FILRE AND ELECTRICAL SHOCK HAZARDS, WHEN SERVICING IF IS 2012/06/20 HEADPHONE 15 Headphone *Option : HEAD_PHONE * Option name of this page : CI_SLOT FILRE AND ELECTRICAL SHOCK HAZARDS, WHEN SERVICING IF IS +3.3V_Normal +3.3V_Normal CI POWER ENABLE CONTROL CI Region (because of Hong Kong) FILRE AND ELECTRICAL SHOCK HAZARDS, WHEN SERVICING IF IS LAN 2012/06/21 21 ETHERNET * H/W option : ETHERNET FILRE AND ELECTRICAL SHOCK HAZARDS, WHEN SERVICING IF IS TUNER_EU 26 TU2603 TDSS-G501D NETCAST4.0 EU&CHUNA_TUNER_BLOCK Close to TUNER close to TUNER ERROR & VALID PIN FILRE AND ELECTRICAL SHOCK HAZARDS, WHEN SERVICING IF IS DVB-S2 LNB Part Allegro Input trace widths should be sized to conduct at least 3A 3A (Option:LNB) Ouput trace widths should be sized to conduct at least 2A AUDIO AMP(STA380BWEF) MSTART DEBUG_4PIN RS-232C FILRE AND ELECTRICAL SHOCK HAZARDS, WHEN SERVICING IF IS LVDS_EU 2012/06/22 11 Pol-change LVDS (EU) Shift [51Pin LVDS Connector] (For FHD 60Hz) Pol-change FOR FHD REVERSE(10bit) SCART / COMPONENT&COMPSIT SCART AMP FULL SCART [SCART AUDIO MUTE] COMPONENT Page Y or module End Established date LCD TV symptom A. Video error No video/ Normal audio (Main B/D Power B/D, LVDS Cable,Speaker Cable,IR B/D Cable,,,) A6 & A3 A4 A1 A2 A4 Revised date 2/14 Picture broken/ Freezing A5 or broadcaster (Cable or Air) . By using Digital signal level meter . By using Diagnostics menu on OSD A6 ( Menu Set up Support Signal Test ) A6 Y A5 Established Check external A7 A8/ A9 A10 date Revised date 5/14 symptom 2013. 01 .09 Vertical/Horizontal bar, residual image, light spot Request repair error Vertical / Horizontal bar, residual image, light spot, external device color error B. Power error 2013. 01 .09 Off when on, off while viewing, power auto on/off A13 Check outlet C. Audio error A15 A16 LCD TV abnormal audio/discontinuation/noise is same after Check input signal compared to No audio C. Audio error 2013. 01 .09 A16 symptom Wrecked audio/ discontinuation/noise D. Function error Remote control & Local switch checking A17 A17 A4 D. Function error Established LCD TV Replace LED driver Mechanical noise is a natural E. Noise Established LCD TV damage F. Exterior defect Established LCD TV Contents of LCD TV Standard Repair Process Detail Technical Manual Defected Type caused by T-Con/ Continue to the next page Contents of LCD TV Standard Repair Process Detail Technical Manual Continued from previous page remote controller, key e rror <ALL MODELS> Power On -> disjoint back case -> check lighting at 2 points. Page Page A. Video error_No video/ Audio LCD TV Page Page Page 1. Check and replace LVDS Cable 2. Check LVDS connection condition A. Video error_Color error <ALL MODELS> A. Video error_Color error Checking item : 1. Defective pixel 2. Residual image 3. MODULE error (ADD-BAR,SCAN BAR..) Appendix : Exchange T-Con Board (1) Page Page Page Page Page B. Power error _No power LCD TV Checking method when power is ON B. Power error _No power LCD TV for adjustment Checking method LCD TV LCD TV