LG U890, Service Manual

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1. INTRODUCTION .............................. 5
1.1 Purpose................................................... 5
1.2 Regulatory Information............................ 5
2. PERFORMANCE...............................7
2.1 System Overview .....................................7
2.2 Usable environment .................................8
2.3 Radio Performance ..................................8
2.4 Current Consumption.............................14
2.5 RSSI BAR ..............................................14
2.6 Battery BAR ...........................................14
2.7 Sound Pressure Level............................15
2.8 Charging ................................................16
3. TECHNICAL BRIEF ........................17
3.1 General Description ...............................17
3.2 GSM Mode.............................................20
3.3 WCDMA Mode .......................................23
3.4 LO Phase-locked Loop ..........................26
3.5 Off-chip RF Components .......................28
3.6 Digital Baseband(DBB/MSM6250A) ......35
3.7 Hardware Architecture ...........................36
3.8 Subsystem(MSM6250A) ........................38
3.9 External memory interface .....................40
3.10 H/W Sub System..................................41
3.11 Main Features ......................................64
3.12 Main Component..................................65
4. TROUBLE SHOOTING ...................70
4.1 RF Component.......................................79
4.2 SIGNAL PATH .......................................71
4.3 Checking VCXO Block ...........................72
4.4 Checking Ant. SW Module Block ...........75
4.5. Checking WCDMA Block ......................77
4.6. Checking GSM Block ............................84
4.7 Bluetooth RF Block ................................92
4.8 Power ON Trouble .................................95
4.9 USB Trouble ..........................................97
4.10 SIM Detect Trouble ..............................98
4.11 Key Sense Trouble ..............................99
4.12 Camera Trouble .................................100
4.13 Main LCD Trouble..............................101
4.14 EL Sheet Trouble ...............................103
4.15 Folder ON/OFF Trouble .....................104
4.16 Camera Direction Detection Trouble..105
4.17 Trans Flash Trouble...........................106
4.18 Audio Trouble Shooting .....................107
4.19 Charger Trouble Shooting..................117
5. DOWNLOAD .................................120
5.1 Introduction ..........................................120
5.2 Downloading Procedure.......................120
5.3 Troubleshooting Download Errors .......134
5.4 Caution.................................................138
6. BLOCK DIAGRAM ........................139
6.1 GSM & WCDMA RF Block...................139
6.2 Interface Diagram ................................141
7. Circuit Diagram ............................145
8. pcb layout .....................................153
9. CALIBRATION ..............................159
9.1 HOT KIMCHI........................................159
9.2 How to use Hot Kimchi.........................163
9.3 HOT KIMCHI Example.........................164
10. EXPLODED VIEW &
REPLACEMENT PART LIST ..... 167
10.1 EXPLODED VIEW ............................ 167
10.2 Replacement Parts
<Mechanic component>.................... 169
<Main component> ........................... 173
10.3 Accessory ......................................... 191
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