LG U8138 Service Manual page 3

Table Of Contents
3.8.2 Transmitter...................................... 85
3.8.3 Frequency Generation .................... 89
4. TROUBLE SHOOTING .................. 91
4.1 Power ON Trouble ................................ 91
4.2 USB Trouble ......................................... 93
4.3 SIM Detect Trouble ............................... 94
4.4 Keypad Trouble..................................... 95
4.5 Camera Trouble .................................... 96
4.6 Main LCD Trouble................................. 98
4.7 Sub LCD Trouble .................................. 99
4.8 Keypad Backlight Trouble ................... 100
4.9 Folder ON/OFF Trouble ...................... 102
4.10 Camera Detection Trouble................ 104
4.11 Camera Flash Trouble ...................... 106
4.12 Audio Trouble Shooting .................... 108
4.13 Charger Trouble Shooting................. 123
4.14 RF Component.................................. 126
4.15 Procedure to check ........................... 128
4.16 Checking Common
Power Source Block.......................... 129
4.16.1 Step 1 ......................................... 130
4.16.2 Step 2 ......................................... 131
4.16.3 Step 3 ......................................... 132
4.16.4 Step 4 ......................................... 133
4.16.5 Checking Regular Part................ 136
4.17 Checking VCXO Block ...................... 137
4.18 Checking Ant. SW Module Block ...... 142
4.19 Checking Antenna Switch Block
input logic.......................................... 143
4.19.1 Mode Logic by TP Command ..... 143
4.19.2 Checking Switch Block
power source .............................. 145
4.20 Checking WCDMA Block .................. 151
4.20.1 Checking ..................................... 152
4.20.2 Checking Ant. SW module .......... 152
4.20.3 Checking Control Signal ............. 152
4.20.4 Checking RF TX Level ................ 155
4.20.5 Checking PAM Block .................. 158
4.20.6 Checking RX I,Q ......................... 162
4.20.7 Checking RX Level ..................... 164
4.21 Checking GSM Block ........................ 166
4.21.1 Checking Regulator Circuit ........ 167
4.21.2 Checking VCXO Block ............... 167
4.21.3 Checking Ant. SW Module .......... 167
4.21.4 Checking Control Signal ............. 168
4.21.5 Checking RF Tx Path.................. 170
4.21.6 Checking RF Rx Path ................. 175
5. BLOCK DIAGRAM ....................... 180
5.1 GSM & WCDMA RF Block.................. 180
5.2 Interface Diagram ............................... 182
5.3 Detailed Interface Signal..................... 184
6. DISASSEMBLY INSTRUCTION... 186
7. DOWNLOAD ................................ 194
8. CALIBRATION ............................. 207
8.1 General Description ............................ 207
8.2 XCALMON Environment ..................... 207
8.2.1 H/W Environment.......................... 207
8.2.2 S/W Environment .......................... 207
8.2.3 Configuration Diagram of
Calibration Environment................ 207
8.3 Calibration Explanation ....................... 208
8.3.1 Overview ....................................... 208
8.3.2 Calibration Items ........................... 208
8.3.3 EGSM 900 Calibration Items ........ 209
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