This document is a service manual for LG LED TVs, specifically models 43LH570*, 43LH570*-U*, 49LH570*, and 49LH570*-U*, all utilizing the LA66L chassis. It provides comprehensive information for servicing, maintenance, and adjustment of these television sets, intended for internal use by LG Electronics for training and service purposes.
Function Description:
The devices are LED TVs designed for North American markets, supporting ATSC/NTSC-M receiving systems with 64 & 256 QAM. They offer a range of screen sizes including 32", 43", 49", and 55", with an aspect ratio of 16:9 and a Full Scan (FS) tuning system. The TVs are capable of displaying various video resolutions, including SDTV (480i, 480p), HDTV (720p, 1080i, 1080p), and PC resolutions via HDMI input (VGA, SVGA, XGA, SXGA, WXGA, WUXGA). Key features include HDMI ARC functionality, Wi-Fi MAC address check, and USB software download capabilities.
Important Technical Specifications:
- Chassis: LA66L
- Models: 43LH570*, 43LH570*-U*, 49LH570*, 49LH570*-U*
- Receiving System: ATSC/NTSC-M / 64 & 256 QAM
- Available Channels:
- VHF: 02~13
- UHF: 14~69
- DTV: 02~69
- CATV: 01~135
- CADTV: 01~135
- Input Voltage: AC 100~240V, 50/60Hz (Mark: 110V, 60Hz for North America)
- Market: North America
- Screen Sizes: 32", 43", 49", 55"
- Aspect Ratio: 16:9
- Tuning System: FS
- Module Types (examples):
- LC550DUE-FJA1 (LGD, FHD)
- NC550DUE-VCCP3 (CSOT, FHD)
- NC490DUE-SADP3 (LGD, FHD)
- NC490DUE-ABEX1 (BOE, FHD)
- HC430DUN-SLVX1 (LGD, FHD)
- HC430DUN-ABVX1 (BOE, FHD)
- HC320DXN-ABVS1 (BOE, HD)
- HC320DXN-SLVS5 (LGD, HD)
- HC320DXN-VHVS1 (SHARP, HD)
- Operating Environment:
- Temperature: 0~40 deg C
- Humidity: ~80%
- Storage Environment:
- Temperature: -20~60 deg C
- Humidity: ~85%
- Supported Video Resolutions (Component 2D input Y, CB/PB, CR/PR):
- 720x480 (15.730 kHz, 60.000 Hz, 13.513 MHz pixel clock) - SDTV, DVD 480i
- 720x480 (31.500 kHz, 60.000 Hz, 27.027 MHz pixel clock) - SDTV 480p
- 1280x720 (45.000 kHz, 60.000 Hz, 74.250 MHz pixel clock) - HDTV 720p
- 1920x1080 (33.750 kHz, 60.000 Hz, 74.250 MHz pixel clock) - HDTV 1080i
- 1920x1080 (67.500 kHz, 60.000 Hz, 148.500 MHz pixel clock) - HDTV 1080p
- Supported Video Resolutions (HDMI Input PC/DTV):
- PC resolutions from 640x350 (EGA) up to 1920x1080 (WUXGA, FHD only)
- DTV resolutions from 640x480 (SDTV 480p) up to 1920x1080 (HDTV 1080p)
- Audio Output (10% max Distortion):
- 49/43LH570 models: 4.5-6.0 W (practical max), 6.0-6.93 Vrms
- 32LH570 models: 2.7-3.6 W (practical max), 4.03-4.64 Vrms
- GND & HI-POT Test:
- Test Voltage: 3000V(AC)/4242V(DC) for 2Poles, 1500V(AC)/2121V(DC) for 3Poles
- Cut off current: 100mA(AC)/100mA(DC)
- Earth Continuity test: ≤0.1Ω at 25A/1 sec (3Poles only)
- Leakage Current: At 0.5mArms
Usage Features:
- Adjustment Instruction: The manual details procedures for ADC Calibration, MAC Address, ESN Key, and Widevine Key download, White Balance adjustment, RS-232C functionality check, factory option setting, shipment mode setting, and GND/HI-POT tests.
- White Balance Adjustment: Includes both auto and manual calibration methods. Manual adjustment involves setting the TV in ADJ mode, calibrating a Color Analyzer probe, and adjusting R/G/B gain values to achieve desired color temperature (Cool, Medium, Warm) and luminance (204 Gray, 80IRE).
- LAN Port Inspection (Ping Test): Utilizes a dedicated test program to verify network connectivity.
- EDID Download: Describes the process for downloading EDID data, which is crucial for optimal resolution display with connected devices.
- HDMI ARC Function Inspection: Outlines the method for checking HDMI Audio Return Channel functionality using specific test equipment.
- Audio Output Check: Provides steps for verifying audio output quality and levels using RF or CVBS input signals.
- USB S/W Download (Optional, Service only): Allows for software updates via a USB stick, with a clear process for detecting, copying, and installing update files. It also notes the importance of re-setting tool options after a software download.
Maintenance Features:
- Safety Precautions: Emphasizes the use of an isolation transformer during servicing, proper replacement of safety-related parts, and performing AC leakage current checks before returning the receiver to the customer. It also includes guidelines for handling electrostatically sensitive (ES) devices and general soldering techniques to prevent damage and ensure safety.
- Servicing Precautions: Provides detailed instructions for safe servicing, including unplugging the AC cord before handling components, proper high voltage testing, avoiding chemical sprays, cleaning electrical contacts, and correctly installing heat sinks.
- Component Removal/Replacement: Specific techniques are outlined for removing and replacing ICs, "Small-Signal" Discrete Transistors, Power Output Transistor Devices, Diodes, Fuses, and Conventional Resistors.
- Circuit Board Foil Repair: Instructions are given for repairing damaged copper patterns on circuit boards, including methods for IC connections and other connections using jumper wires.
- Troubleshooting Guide: Flowcharts are provided for diagnosing common issues such as "No video (Main IC Block)," "No video (Back-end Block)," "Digital / Analog TV Video No signal," "AV Video No signal," "Component Video No signal," "HDMI Video No signal," "USB No storage," "All source Audio," "Digital / Analog TV No sound," "AV No sound," "Component No sound," and "HDMI No sound." These guides direct technicians through a series of checks and potential component replacements.
- Exploded View and Disassembly Instructions: Detailed diagrams and step-by-step instructions are included for disassembling the TV, showing the location of various components and fasteners. This is crucial for accessing internal parts for repair or replacement.
- Block Diagram: A block diagram of the M2 (NON MCP) main board is provided, illustrating the interconnections between key components such as the Tuner, Digital Demod, Analog Demod, DDR3 memory, EEPROM, eMMC, LVDS, HDMI MUX, Audio AMP, USB_WIFI, CVBS/YPbPr, SPDIF OUT, Ethernet, and RS-232. This helps in understanding the overall architecture and signal flow within the TV.
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