Table Of Contents - LG -A155 Service Manual

1. INTRODUCTION ..................................................................5
1.1 Purpose ............................................................................................... 5
1.2 Regulatory Information ............................................................... 5
1. Abbreviations ................................................................................... 7
2. PERFORMANCE ...................................................................9
2.1 H/W Features .................................................................................... 9
2.2 Technical Specification ...............................................................11
3. TECHNICAL BRIEF .............................................................16
.1 Digital Main Processor ................................................................16
.2 Power Management ....................................................................21
. FEM with integrated Power Amplifier Module
(SKY77547, U0) .........................................................................26
.4 Clocks ................................................................................................28
.5 RFSYS of MT625 (U102) ...........................................................0
.6 MEMORY(PF8F4050M0YDE, U101) ..................................2
.7 BT Module .......................................................................................5
.8 SIM Card Interface ........................................................................9
.9 Micro-SD Card Interface.............................................................41
.10 LCD Interface ...............................................................................44
.11 Battery Charger Interface .......................................................46
.12 Keypad Interface ........................................................................47
.1 Audio Front-End .........................................................................50
.15 KEY BACLKLIGHT LED Interface ............................................5
.16 Vibrator Interface .......................................................................54
4. TROUBLE SHOOTING .......................................................55
4.1 RF Component...............................................................................55
4.2 RX Trouble .......................................................................................56
4. TX Trouble ........................................................................................60
4.4 Power On Trouble .........................................................................64
4.5 Charging Trouble ..........................................................................67
4.6 Vibrator Trouble .............................................................................69
4.7 LCD Trouble .....................................................................................71
4.9 Speaker Trouble ............................................................................75
4.10 Earphone Trouble ......................................................................77
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Only for training and service purposes

Table Of Contents

4.11 Receiver Trouble .........................................................................79
4.12 Microphone Trouble .................................................................81
4.1 SIM Card Interface Trouble .....................................................8
4.14 SIM2 Card Interface Trouble ..................................................85
4.15 KEY backlight Trouble ..............................................................87
4.16 Micro SD (uSD) Trouble ............................................................89
4.17 Bluetooth Trouble ......................................................................91
4.18 FM Radio Trouble .......................................................................9
5. DOWNLOAD ......................................................................95
6. BLOCK DIAGRAM ........................................................... 108
7. CIRCUIT DIAGRAM ........................................................ 109
8. BGA PIN MAP ................................................................. 115
9. PCB LAYOUT ................................................................... 117
10. ENGINEERING MODE .................................................. 123
11. RF CALIBRATION ......................................................... 125
11.1 Configuration of Tachyon .................................................... 125
11.2 How to use Tachyon ............................................................... 127
12 EXPLODED VIEW & REPLACEMENT PART LIST .......... 129
12.1 EXPLODED VIEW ...................................................................... 129
12.2 Replacement Parts.................................................................. 11
12. Accessory ................................................................................... 142
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