LG SJ3 Service Manual page 16

ONE POINT REPAIR GUIDE ............................................................................................................................ 3-2
1. NO POWER PROBLEM (PVDD) ............................................................................................................ 3-2
2. POWER ON ERROR .............................................................................................................................. 3-3
3. NO SOUND (PORTABLE FUNCTION) .................................................................................................. 3-4
4. NO WIRELESS ....................................................................................................................................... 3-5
5. NO BLUETOOTH .................................................................................................................................... 3-6
6. NO SOUND (OPTICAL) .......................................................................................................................... 3-7
7. D(DC) PROTECTION ............................................................................................................................. 3-8
8. S(SHUT DOWN) PROTECTION............................................................................................................. 3-9
9. B(BURNT) PROTECTION .................................................................................................................... 3-10
WAVEFORMS OF MAJOR CHECK POINT .................................................................................................... 3-11
1. CRYSTAL .............................................................................................................................................. 3-11
2. FLASH MEMORY ................................................................................................................................. 3-11
3. TACT KEY ............................................................................................................................................. 3-12
4. REMOTE CONTROL ............................................................................................................................ 3-13
5. OPTICAL ............................................................................................................................................... 3-14
6. PORTABLE ........................................................................................................................................... 3-15
7. AUDIO PWM ......................................................................................................................................... 3-16
WIRING DIAGRAM .......................................................................................................................................... 3-17
BLOCK DIAGRAMS ........................................................................................................................................ 3-19
1. SYSTEM BLOCK DIAGRAM ................................................................................................................ 3-19
2. POWER BLOCK DIAGRAM ................................................................................................................. 3-21
CIRCUIT VOLTAGE CHART ........................................................................................................................... 3-23
1. CONNECTORS ..................................................................................................................................... 3-23
2. OTHERS ............................................................................................................................................... 3-25
PRINTED CIRCUIT BOARD DIAGRAMS ....................................................................................................... 3-27
1. SMPS P. C. BOARD DIAGRAM ........................................................................................................... 3-27
2. MAIN P. C. BOARD DIAGRAM ............................................................................................................ 3-29
3. FRONT P. C. BOARD DIAGRAM ......................................................................................................... 3-31
SECTION 3
ELECTRICAL
CONTENTS
3-1