LG KE820 Service Manual Download

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1. INTRODUCTION ...............................7

1.1 Purpose .................................................. 7
1.2 Regulatory Information............................ 7
1.3 ABBREVIATION ..................................... 9

2. PERFORMANCE .............................11

2.1 H/W Features.........................................11
2.2 Technical specification...........................12

3. TECHNICAL BRIEF ........................19

3.1 KE820 / KG99 Component

Block diagram. .......................................19

3.2 Baseband Processor (BBP)

Introduction ............................................21

3.3 Power management IC ..........................33
3.4 Power ON/OFF ......................................39
3.5 SIM interface..........................................40
3.6 Memory ..................................................41
3.7 LCD Display ...........................................42
3.8 Keypad Switching & Scanning ...............43
3.9 Keypad back-light illumination ...............44
3.10 LCD back light illumination...................46
3.11 Battery current consumption monitor ...48
3.12 JTAG & ETM interface connector ........48
3.13 Audio....................................................49
3.14 Multi port switch ...................................51
3.15 USB charging circuit ............................53
3.16 FM radio with RDS function .................54
3.17 BLUETOOTH .......................................55
3.18 Micro SD external memory card slot....58
3.19 18pin Multi Media Interface connector ....60
3.20 General Description .............................62
3.21 Receiver part........................................63
3.22 Transmitter part....................................64
3.23 RF synthesizer .....................................66
3.24 VCTCXO ..............................................66
3.25 Front End Module control.....................67
3.26 Power Amplifier Module .......................67

4. PCB layout......................................69

4.1 Main & Sub PCB component

placement ..............................................69

5. Trouble shooting............................76

5.1 Trouble shooting test setup....................76
5.2 Power on Trouble...................................76
5.3 Charging trouble ....................................80
5.4 LCD display trouble................................82
5.5 Camera Trouble .....................................83
5.6 Receiver & Speaker trouble ...................86
5.7 Microphone trouble ................................88
5.8 Vibrator trouble ......................................90
5.9 Keypad back light trouble.......................92
5.10 SIM card trouble...................................94
5.11 MicroSD trouble ...................................96
5.12 RF PART TROUBLESHOOTING ........98

6. Download & S/W upgrade...............114

6.1 S/W download setup ............................114
6.2 Download program user guide.............115

7. CIRCUIT DIAGRAM ......................119

8. PCB LAYOUT ................................125

9. RF Calibration ..............................129

9.1 Test Equipment Setup .........................129
9.2 Calibration Steps..................................129

10. ENGINEERING MODE ................135

11. STANDALONE TEST ..................136

11.1 Test Program Setting .........................136
11.2 Tx Test ...............................................139
11.3 Rx Test...............................................140

12. EXPLODED VIEW &

REPLACEMENT PART LIST ..... 141

12.1 Exploded View .................................. 141

12.2 Replacement Parts ............................143
12.3 Accessory ......................................... 161

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