LG FH2 - Troubleshooting Guide; General Problem Solving; Radio Reception Issues

SECTION 3
ELECTRICAL
CONTENTS
ONE POINT REPAIR GUIDE ............................................................................................................................ 3-2
1. NO POWER PROBLEM ......................................................................................................................... 3-2
2. SPEAKER NO SOUND ........................................................................................................................... 3-6
3. PORTABLE FUNCTION DOESN’T WORK ............................................................................................ 3-7
4. BT FUNCTION DOESN’T WORK ........................................................................................................... 3-8
ELECTRICAL TROUBLESHOOTING GUIDE ................................................................................................... 3-9
1. SYSTEM POWER SUPPLY ON SMPS BOARD .................................................................................... 3-9
2. NO POWER .......................................................................................................................................... 3-12
3. NO BUTTON OPERATION ................................................................................................................... 3-13
4. NO BT OPERATION ............................................................................................................................. 3-14
5. NO AUDIO OUTPUT ............................................................................................................................ 3-15
WAVEFORMS OF MAJOR CHECK POINT .................................................................................................... 3-18
1. SYSTEM PART-1 (X-TAL) .................................................................................................................... 3-18
2. SYSTEM PART-2 (I2S SIGNAL) .......................................................................................................... 3-19
3. SYSTEM PART-3 (I2C SIGNAL) .......................................................................................................... 3-20
4. SYSTEM PART-4 (PWM SIGNAL) ....................................................................................................... 3-21
5. SYSTEM PART-5 (BATTERY INPUT - AC OFF STATUS) .................................................................. 3-22
WIRING DIAGRAM .......................................................................................................................................... 3-23
BLOCK DIAGRAMS ........................................................................................................................................ 3-25
1. SYSTEM BLOCK DIAGRAM ................................................................................................................ 3-25
2. POWER BLOCK DIAGRAM ................................................................................................................. 3-27
CIRCUIT VOLTAGE CHART ........................................................................................................................... 3-29
1. ICs ......................................................................................................................................................... 3-29
2. CONNECTORS ..................................................................................................................................... 3-30
PRINTED CIRCUIT BOARD DIAGRAMS ....................................................................................................... 3-31
1. SMPS P. C. BOARD DIAGRAM ........................................................................................................... 3-31
2. MAIN P. C. BOARD DIAGRAM ............................................................................................................ 3-33
3. FRONT P. C. BOARD DIAGRAM ......................................................................................................... 3-37
4. FM P. C. BOARD DIAGRAM ................................................................................................................ 3-39
5. VOLUME CONTROL P. C. BOARD DIAGRAM ................................................................................... 3-39
6. MIC P. C. BOARD DIAGRAM ............................................................................................................... 3-41
3-1