lg as990 service manual filetype pdf

The LG AS990 is a high-performance mobile device requiring professional service and maintenance. This service manual provides comprehensive technical documentation for authorized service personnel, including disassembly procedures, component specifications, troubleshooting guides, and repair instructions. Below are key sections covering safety precautions, technical specifications, repair procedures, and diagnostic information.

1. Product Overview 2. Safety Precautions 3. Technical Specifications 4. Disassembly Procedures 5. Component Locations 6. Troubleshooting Guide 7. Circuit Diagrams 8. Replacement Parts 9. Testing Procedures 10. Software Installation 11. Regulatory Compliance

Product Overview

The LG AS990 features advanced mobile technology with multiple hardware components requiring specialized service procedures.

Component	Description
Main Board	Central processing unit with integrated circuits
Display Assembly	LCD screen with touch digitizer
Battery	Lithium-ion power source
Camera Modules	Front and rear camera assemblies
Connectivity Board	Wi-Fi, Bluetooth, and cellular modules
Audio Components	Speaker, microphone, and audio jack
Charging Port	USB connectivity and power input
Buttons & Switches	Power, volume, and function controls
SIM Card Tray	Dual SIM card slot assembly
Memory Card Slot	Expandable storage compartment

Safety Precautions

Essential safety procedures for service technicians.

Always disconnect power source before disassembly.
Use anti-static wrist strap when handling circuit boards.
Follow proper battery handling procedures.
Use only authorized replacement parts.
Document all disassembly steps for reassembly.

WARNING! High voltage components present; follow electrostatic discharge precautions. Battery may explode if mishandled.

Technical Specifications

Model: LG AS990
Processor: Quad-core CPU
Memory: 2GB RAM, 16GB internal storage
Display: 5.5-inch HD LCD
Camera: 13MP rear, 5MP front
Connectivity: 4G LTE, Wi-Fi 802.11ac, Bluetooth 4.0
Battery: 3000mAh lithium-ion
Operating System: Android with LG UI
Dimensions: Standard smartphone form factor
Weight: Approx. 150g

Disassembly Procedures

Step-by-step disassembly instructions for authorized service personnel.

Power off device and remove SIM card tray.
Remove rear cover using plastic opening tools.
Disconnect battery connector from main board.
Remove mounting screws securing internal components.
Carefully disconnect ribbon cables and flex circuits.
Remove main board assembly from chassis.
Separate display assembly from front housing.

CAUTION! Use proper tools to avoid damaging components. Document screw locations for reassembly.

Component Locations

Detailed component identification and location mapping.

Component	Location	Identification
Main Board	Center of device	Green PCB with multiple ICs
Battery Connector	Lower left corner	White 4-pin connector
Display Flex	Top center	Brown ribbon cable
Camera Flex	Upper right	Black ribbon with gold contacts
Audio Board	Bottom edge	Small black PCB

Troubleshooting Guide

Common issues and diagnostic procedures.

Symptom	Possible Cause	Corrective Action
No power	Battery/charging circuit	Check battery voltage; test charging port; replace power IC
No display	LCD/digitizer damage	Test display flex connection; replace LCD assembly
No network	Antenna/RF circuit	Check antenna connections; test RF components
Overheating	Processor/battery	Monitor temperature; replace thermal paste; check battery
Audio issues	Speaker/circuit	Test audio output; replace speaker; check audio IC

Circuit Diagrams

Detailed schematics for electronic troubleshooting.

Power management circuit
Processor and memory block diagram
RF and cellular circuitry
Audio amplification circuit
Display driver circuitry
Camera interface circuits

Note: Refer to full schematic diagrams in appendix for complete circuit analysis.

Replacement Parts

Authorized replacement components and part numbers.

Component	Part Number	Specifications
LCD Display	LG-AS990-LCD-01	5.5-inch HD, touch digitizer
Battery	LG-AS990-BAT-01	3000mAh lithium-ion
Main Board	LG-AS990-MB-01	Complete assembly
Camera Module	LG-AS990-CAM-01	13MP with autofocus
Charging Port	LG-AS990-USB-01	Micro USB assembly

Testing Procedures

Comprehensive testing after repair completion.

Power on test: Verify device boots normally
Display test: Check for dead pixels and touch response
Audio test: Verify speaker and microphone functionality
Connectivity test: Test Wi-Fi, Bluetooth, and cellular
Camera test: Verify both cameras operational
Battery test: Check charging and discharge cycles
Stress test: Run diagnostic software for stability

Software Installation

Firmware and software installation procedures.

Download official firmware from LG support site
Enter download mode (Volume Down + Power)
Connect to computer via USB cable
Run LG Flash Tool with appropriate .kdz file
Follow on-screen instructions for firmware installation
Reboot device and perform factory reset if needed

WARNING! Use only official firmware to avoid bricking device.

Regulatory Compliance

FCC, CE, and other regulatory compliance information. Device complies with international standards for electromagnetic compatibility and safety. Contains FCC ID: BEJAS990. Meets RoHS requirements for hazardous substance restrictions.

For technical support and additional service documentation, visit www.lg.com or contact LG authorized service centers.