LG U880 Service Manual page 3

Table Of Contents
4. TROUBLE SHOOTING ...................74
4.1 RF Component.......................................74
4.2 SIGNAL PATH .......................................75
4.3 Checking VCXO Block ...........................76
4.4 Checking Ant. SW Module Block ...........79
4.5 Checking WCDMA Block .......................81
4.5.1 Checking VCXO Block .....................82
4.5.2 Checking Ant. SW module ...............82
4.5.3 Checking RF TX Level .....................82
4.5.4 Checking PAM Block .......................84
4.5.5 Check RF Rx Level ..........................85
4.6 Checking GSM Block .............................87
4.6.1 Checking VCO Block .......................88
4.6.2 Checking Ant. SW Module ...............90
4.6.3 Checking RF Tx level.......................90
4.6.4 Checking PAM Block .......................92
4.6.5 Checking RF Rx Block .....................93
4.7 Bluetooth RF Block ................................95
4.8 Power ON Trouble .................................98
4.9 USB Trouble ........................................100
4.10 SIM Detect Trouble ............................101
4.11 Key Sense Trouble ............................102
4.12 Camera Trouble .................................103
4.13 Main LCD Trouble..............................104
4.14 Keypad Backlight Trouble ..................106
4.15 Folder ON/OFF Trouble .....................107
4.16 Camera Direction Detection Trouble..108
4.17 Trans Flash Trouble...........................109
4.18 Audio Trouble Shooting .....................110
4.19 Charger Trouble Shooting..................120
5. DOWNLOAD .................................123
5.1 Introduction ..........................................123
5.2 Downloading Procedure.......................123
5.3 Troubleshooting Download Errors .......136
6. BLOCK DIAGRAM ........................141
6.1 BLK diagram ........................................141
6.2 GSM & WCDMA RF Block...................142
6.3 Interface Diagram ................................144
7. Circuit Diagram ............................147
8. pcb layout .....................................155
9. CALIBRATION ..............................161
9.1 HOT KIMCHI........................................161
9.1.1 Directory structure..........................161
9.1.2 Setup file (Info_Db.txt) ...................162
9.1.3 Setup file item ................................163
9.1.4 Example for setting file ..................164
9.2 How to use Hot Kimchi.........................165
9.3 HOT KIMCHI Example.........................166
10. EXPLODED VIEW &
REPLACEMENT PART LIST ..... 170
10.1 EXPLODED VIEW ............................ 170
10.2 Replacement Parts
<Mechanic component>.................... 173
<Main component> ........................... 177
10.3 Accessory ......................................... 196
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