LG LST-3100A Service Manual page 10

SOFTWARE CORRUPTION PROBLEM
ELECTRICAL TROUBLESHOOTING GUIDE
1. POWER(SMPS) CIRCUIT.........................................................................................................................3-5
2. AUDIO CIRCUIT .......................................................................................................................................3-7
1) NO ATSC AUDIO
2) NO OPTICAL OUTPUT AUDIO
3) NO COAXIAL OUTPUT AUDIO
3. CPU (SYSTEM CONTROL) TROUBLESHOOTING ..............................................................................3-14
4. VIDEO TROUBLESHOOTING FLOW ....................................................................................................3-21
5. ATSC/ QAM FRONT- END TROUBLESHOOTING FLOW ....................................................................3-31
6. FRONT PANEL TROUBLESHOOTING FLOW ......................................................................................3-32
OVERALL BLOCK DIAGRAM.........................................................................................................................3-34
1. OVERALL BLOCK DIAGRAM 1 ............................................................................................................3-34
2. OVERALL BLOCK DIAGRAM 2 ............................................................................................................3-36
3. OVERALL BLOCK DIAGRAM 3 ............................................................................................................3-38
BLOCK DIAGRAM & SIGNAL FLOW.............................................................................................................3-40
1. POWER(SMPS) BLOCK DIAGRAM ......................................................................................................3-40
2. SYSTEM CONTRL BLOCK DIAGRAM..................................................................................................3-42
3. AUDIO PROCESSING BLOCK DIAGRAM ............................................................................................3-44
4. VIDEO PROCESSING BLOCK DIAGRAM ............................................................................................3-46
CIRCUIT DIAGRAM .........................................................................................................................................3-48
1. POWER(SMPS) CIRCUIT DIAGRAM ....................................................................................................3-48
2. CPU, AUDIO, POWER CIRCUIT DIAGRAM..........................................................................................3-50
3. HD2, TUNER, DVI CIRCUIT DIAGRAM.................................................................................................3-52
4. ATSCII-STB CIRCUIT DIAGRAM...........................................................................................................3-54
5. FRONT CIRCUIT DIAGRAM ..................................................................................................................3-56
PRINTED CIRCUIT DIAGRAMS......................................................................................................................3-58
1. DIGITAL MAIN P.C.BOARD(BOTTOM)..................................................................................................3-58
2. DIGITAL MAIN P.C.BOARD(TOP)..........................................................................................................3-60
3. FRONT P.C.BOARD ...............................................................................................................................3-62
4. POWER P.C.BOARD ..............................................................................................................................3-62
SECTION 3
ELECTRICAL
CONTENTS
.....................................................................................................3-2
.....................................................................................................................................3-7
...............................................................................................................3-11
..............................................................................................................3-12
............................................................................................3-5
3-1