LG FA162 Service Manual page 20

TONE POINT REPAIR GUIDE .......................................................................................................................... 3-2
1. NO POWER PROBLEM ......................................................................................................................... 3-2
2. SPEAKER NO AUDIO OUTPUT ............................................................................................................ 3-3
3. USB NO DETECT ................................................................................................................................... 3-4
4. NO BOOTING ......................................................................................................................................... 3-5
ELECTRICAL TROUBLESHOOTING GUIDE OF AUDIO PART ..................................................................... 3-6
1. μ-COM PART CHECK-1 ......................................................................................................................... 3-6
2. FLD DISPLAY CHECK ........................................................................................................................... 3-7
3. TOUCH PAD CHECK ............................................................................................................................. 3-8
4. PWM MODULATION PART .................................................................................................................... 3-9
5. POWER AMP PART CHECK ............................................................................................................... 3-10
6. AUX FUNCTION CHECK ..................................................................................................................... 3-11
7. TUNER FUNCTION CHECK................................................................................................................. 3-12
8. SMPS POWER CIRCUIT ...................................................................................................................... 3-13
ELECTRICAL TROUBLESHOOTING GUIDE OF CD PART ......................................................................... 3-16
1. POWER CHECK GUIDE ...................................................................................................................... 3-16
2. CD PART .............................................................................................................................................. 3-17
3. OPEN CLOSE NG ................................................................................................................................ 3-18
4. " READING " DISPLAY CHECK (= ONLY "CD" DISPLAY) .................................................................. 3-18
5. READING OK CHECK (= "NO DISC" DISPLAY) ................................................................................. 3-19
6. USB PART ............................................................................................................................................ 3-23
WAVEFORMS OF MAJOR CHECK POINT .................................................................................................... 3-24
WIRING DIAGRAM .......................................................................................................................................... 3-29
BLOCK DIAGRAMS ........................................................................................................................................ 3-31
1. SYSTEM BLOCK DIAGRAM ................................................................................................................ 3-31
2. SMPS BLOCK DIAGRAM ..................................................................................................................... 3-33
3. POWER DIAGRAM ............................................................................................................................... 3-35
CIRCUIT DIAGRAMS ...................................................................................................................................... 3-37
1. SMPS CIRCUIT DIAGRAM .................................................................................................................. 3-37
2. MAIN - MICOM CIRCUIT DIAGRAM .................................................................................................... 3-39
3. MAIN - DSP CIRCUIT DIAGRAM ......................................................................................................... 3-41
4. MAIN - SERVO CIRCUIT DIAGRAM .................................................................................................... 3-43
5. MAIN - AMP CIRCUIT DIAGRAM......................................................................................................... 3-45
6. FRONT CIRCUIT DIAGRAM ................................................................................................................ 3-47
7. TOUCH CIRCUIT DIAGRAM ................................................................................................................ 3-49
8. TOUCH SLIDE CIRCUIT DIAGRAM .................................................................................................... 3-50
CIRCUIT VOLTAGE CHART ........................................................................................................................... 3-51
PRINTED CIRCUIT BOARD DIAGRAMS ....................................................................................................... 3-53
1. SMPS P.C.BOARD ............................................................................................................................... 3-53
2. MAIN P.C.BOARD ................................................................................................................................ 3-55
3. FRONT P.C.BOARD ............................................................................................................................. 3-59
4. TOUCH P.C.BOARD ............................................................................................................................. 3-61
5. TOUCH SLIDE P.C.BOARD ................................................................................................................. 3-61
SECTION 3
ELECTRICAL
CONTENTS
3-1