LG CK57 Service Manual page 38

ONE POINT REPAIR GUIDE ............................................................................................................................3-2
1. NO POWER ............................................................................................................................................3-2
2. NO BOOTING WHEN POWER ON THE SET........................................................................................3-4
3. VFD IS NOT DISPLAYED WHEN POWER ON THE SET .....................................................................3-5
4. NO OPERATION OF MD ........................................................................................................................3-6
5. NO SOUND ...........................................................................................................................................3-11
ELECTRICAL TROUBLESHOOTING GUIDE .................................................................................................3-16
1. POWER (SMPS) ...................................................................................................................................3-16
2. MCS PART CHECK ..............................................................................................................................3-19
3. IC503 CHECK .......................................................................................................................................3-19
4. FLD DISPLAY CHECK .........................................................................................................................3-20
5. PWM MODULATION CHECK ...............................................................................................................3-21
6. POWER AMP PART CHECK ...............................................................................................................3-22
7. AUX / TUNER FUNCTION CHECK ......................................................................................................3-23
8. TUNER FUNCTION CHECK.................................................................................................................3-23
9. CD FUNCTION .....................................................................................................................................3-24
10. DOUBLE USB FUNCTION ...................................................................................................................3-25
WAVEFORMS OF MAJOR CHECK POINT ....................................................................................................3-26
WIRING DIAGRAM ..........................................................................................................................................3-27
BLOCK DIAGRAMS ........................................................................................................................................3-29
1. SYSTEM BLOCK DIAGRAM ................................................................................................................3-29
2. POWER BLOCK DIAGRAM .................................................................................................................3-31
CIRCUIT VOLTAGE CHART ...........................................................................................................................3-33
1. CONNECTORS .....................................................................................................................................3-33
2. CAPACITORS .......................................................................................................................................3-33
3. ICs .........................................................................................................................................................3-34
PRINTED CIRCUIT BOARD DIAGRAMS .......................................................................................................3-35
1. SMPS P.C.BOARD ...............................................................................................................................3-35
2. MAIN P.C.BOARD ................................................................................................................................3-37
3. FRONT P.C.BOARD .............................................................................................................................3-39
4. MIC P.C.BOARD DIAGRAM .................................................................................................................3-41
SECTION 3
ELECTRICAL
CONTENTS
3-1
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