LG LRM-519 Service Manual page 15

ELECTRICAL TROUBLESHOOTING GUIDE ..................................................................................................3-2
1. POWER(SMPS) CIRCUIT ........................................................................................................................3-2
2. SYSTEM PART CIRCUIT .........................................................................................................................3-3
3. VIDEO PART-1..........................................................................................................................................3-5
4. YPBPR VIDEO OUTPUT TROUBLESHOOTING.....................................................................................3-6
5. S-VIDEO VIDEO OUTPUT TROUBLESHOOTING ..................................................................................3-7
6. CVBS VIDEO OUTPUT TROUBLESHOOTING .......................................................................................3-8
7. AUDIO TROUBLESHOOTING..................................................................................................................3-9
8. TUNER TROUBLESHOOTING...............................................................................................................3-10
9. ETHERNET TROUBLESHOOTING ........................................................................................................3-11
10. MODEM TROUBLESHOOTING ...........................................................................................................3-12
11. DVD TROUBLESHOOTING..................................................................................................................3-13
12. IR BLASTER TROUBLESHOOTING....................................................................................................3-14
13. SERIAL (RS-232) TROUBLESHOOTING.............................................................................................3-15
WAVEFORMS ..................................................................................................................................................3-16
1. SYSTEM PART-1 ....................................................................................................................................3-16
2. SYSTEM PART-2 ....................................................................................................................................3-17
3. VIDEO PART-1........................................................................................................................................3-18
4. VIDEO PART-2........................................................................................................................................3-19
5. VIDEO PART-3........................................................................................................................................3-20
6. VIDEO PART-4........................................................................................................................................3-21
7. AUDIO PART-1........................................................................................................................................3-22
8. AUDIO PART-2........................................................................................................................................3-23
9. AUDIO PART-3........................................................................................................................................3-24
10. ETHERNET PART ................................................................................................................................3-25
11. SUPER IO & FRONT INTERFACE PART.............................................................................................3-26
BLOCK DIAGRAMS ........................................................................................................................................3-27
1. TOTAL BLOCK DIAGRAM ......................................................................................................................3-27
2. WRING BLOCK DIAGRAM.....................................................................................................................3-28
3. POWER BLOCK DIAGRAM ...................................................................................................................3-29
4. SIGNAL PATH BLOCK DIAGRAM..........................................................................................................3-30
5. BLOCK DIAGRAM ..................................................................................................................................3-31
CIRCUIT DIAGRAMS ......................................................................................................................................3-32
1. POWER(SMPS) CIRCUIT DIAGRAM ....................................................................................................3-32
2. POWER CIRCUIT DIAGRAM .................................................................................................................3-34
3. CPU CIRCUIT DIAGRAM .......................................................................................................................3-36
4. GMCH CIRCUIT DIAGRAM....................................................................................................................3-38
5. ICH4 CIRCUIT DIAGRAM ......................................................................................................................3-41
6. CLOCK & LPC CIRCUIT DIAGRAM.......................................................................................................3-42
7. MEMORY/IDE CIRCUIT DIAGRAM........................................................................................................3-44
8. LAN/USB/MODEM CIRCUIT DIAGRAM ................................................................................................3-46
9. VIDEO CONVERTER & AC97 CODEC CIRCUIT DIAGRAM ................................................................3-48
10. MPEG-II ENCODER & AV DECODER (CX23418) CIRCUIT DIAGRAM .............................................3-50
11. TUNER & EXTERNAL AV INPUT CIRCUIT DIAGRAM........................................................................3-52
12. AUDIO/VIDEO INPUT INTERFACE CIRCUIT DIAGRAM ....................................................................3-54
13. MISCELLANEDUS CIRCUIT DIAGRAM ..............................................................................................3-56
14. EXTERNAL I/F CIRCUIT DIAGRAM ....................................................................................................3-58
PRINTED CIRCUIT DIAGRAMS .....................................................................................................................3-60
1. MAIN PRINTED CIRCUIT DIAGRAMS(TOP VIEW) ..............................................................................3-60
2. MAIN PRINTED CIRCUIT DIAGRAMS(BOTTOM VIEW) ......................................................................3-62
3. KEY PRINTED CIRCUIT DIAGRAM.......................................................................................................3-64
4. TIMER PRINTED CIRCUIT DIAGRAM...................................................................................................3-64
5. POWER PRINTED CIRCUIT DIAGRAM ................................................................................................3-66
SECTION 3
ELECTRICAL
CONTENTS
3-1