LG CM1530, Service Manual

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SECTION 3
ELECTRICAL
CONTENTS
ELECTRICAL TROUBLESHOOTING GUIDE
.................................................................................... 3-2
1. SMPS PART ........................................................................................................................................... 3-2
2. AUDIO ABNORMAL ............................................................................................................................... 3-4
3. AUDIO ABNORMAL IN FUNCTION MODE ........................................................................................... 3-5
4. CD PART ................................................................................................................................................ 3-6
5. CD READING CHECK............................................................................................................................ 3-7
6. USB PART .............................................................................................................................................. 3-8
7. VFD DISPLAY CHECK ........................................................................................................................... 3-9
WAVEFORMS OF MAJOR CHECK POINT
..................................................................................... 3-10
1. WHEN POWER ON, RESET & DATA ETC WAVEFORM ................................................................... 3-10
2. WHEN USB FUNCTION OPERATING ................................................................................................ 3-12
3. STARTING ACTION WAVEFORM IN MD DEVICE (SLED HOME) .................................................... 3-13
4. RADIO OPERATING TU_DA/ CLK/ RST WAVEFORM ....................................................................... 3-14
5. AT FIRST ACTION, FOCUS SIGNAL A/ B/ C/ D ................................................................................. 3-15
6. RF WAVEFORM (ANALOG SCOPE) ................................................................................................... 3-16
WIRING DIAGRAM
................................................................................................................................... 3-17
BLOCK DIAGRAM
.................................................................................................................................... 3-19
CIRCUIT DIAGRAMS
............................................................................................................................... 3-21
1. SMPS CIRCUIT DIAGRAM .................................................................................................................. 3-21
2. MAIN-1 CIRCUIT DIAGRAM ................................................................................................................ 3-23
3. MAIN-2 CIRCUIT DIAGRAM ................................................................................................................ 3-25
4. MAIN-3 CIRCUIT DIAGRAM ................................................................................................................ 3-27
5. MAIN-4 CIRCUIT DIAGRAM ................................................................................................................ 3-29
6. DISPLAY & USB CIRCUIT DIAGRAM ................................................................................................. 3-31
7. IPOD CIRCUIT DIAGRAM .................................................................................................................... 3-33
CIRCUIT VOLTAGE CHART
................................................................................................................. 3-35
1. ICs......................................................................................................................................................... 3-35
2. DIODES ................................................................................................................................................ 3-35
3. CAPACITORS....................................................................................................................................... 3-36
4. CONNECTORS .................................................................................................................................... 3-37
PRINTED CIRCUIT BOARD DIAGRAMS
......................................................................................... 3-39
1. SMPS P.C.BOARD ............................................................................................................................... 3-39
2. MAIN P.C.BOARD ................................................................................................................................ 3-41
3. DISPLAY P.C.BOARD .......................................................................................................................... 3-45
4. USB P.C.BOARD .................................................................................................................................. 3-45
5. IPOD P.C.BOARD ................................................................................................................................ 3-46
3-1