Table Of Contents - LG U250 Service Manual

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 ...........................................15
2.7 Sound Pressure Level............................16
2.8 Charging ................................................16
3. TECHNICAL BRIEF ........................17
3.1 General Description ...............................17
3.2 GSM Mode.............................................19
3.3 UMTS Mode...........................................23
3.4 LO generation and distribution circuits...25
3.5 Off-chip RF Components .......................25
3.6 Digital Baseband(DBB/MSM6245).........34
3.7 Block Diagram(MSM6245).....................36
3.8 Subsystem(MSM6245) ..........................37
3.9 Power Block ...........................................45
3.10 External memory interface ...................50
3.11 H/W Sub System..................................52
3.12 Main Features ......................................68
4. TROUBLE SHOOTING ...................73
4.1 RF Component.......................................73
4.2 SIGNAL PATH_UMTS RF .....................75
4.3 SIGNAL PATH_GSM RF .......................76
4.4 Checking VC-TCXO Block .....................77
4.5 Checking Front-End Module Block ........79
4.6 Checking UMTS Block ...........................81
4.7 Checking GSM Block .............................86
4.8 Checking Bluetooth Block ......................92
4.9 Power ON Troubleshooting....................94
4.10 Charger Troubleshooting .....................96
4.11 USB Troubleshooting...........................99
4.12 SIM Detect Troubleshooting ..............100
4.13 Camera Troubleshooting ...................102
4.14 Keypad Backlight Troubleshooting ....105
4.15 Main LCD Troubleshooting ................106

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4.16 Receiver Path ....................................107
4.17 Headset path......................................109
4.18 Speaker phone path...........................111
4.19 Main microphone ...............................113
4.20 Headset microphone..........................115
4.21 Vibrator ..............................................117
5. DOWNLOAD..................................119
5.1 U250/KU250 DOWNLOAD ..................119
5.1.1 Introduction ...................................119
5.1.2 Downloading Procedure ...............119
5.1.3 Troubleshooting Download Errors 129
5.1.4 Caution .........................................133
6. BLOCK DIAGRAM ........................134
6.1 GSM & UMTS RF Block.......................134
6.2 Interface Diagram ................................136
7. Circuit Diagram ............................143
8. pcb layout .....................................147
9. Calibration & RF Auto Test
Program (Hot Kimchi)..................149
9.1 Configuration of HOT KIMCHI .............149
9.2 How to use HOT KIMCHI.....................152
10. Factory Test Mode .....................154
10.1. Test Program Setting ........................154
10.2. WCDMA Test Mode ..........................155
10.3. GSM Test Mode................................156
11. EXPLODED VIEW &
REPLACEMENT PART LIST ..... 157
11.1 EXPLODED VIEW ............................ 157
11.2 Replacement Parts
<Mechanic component>.................... 159
<Main component> ........................... 161
11.3 Accessory ......................................... 174