3-1
Copyright © 2008 LG Electronics. Inc. All right reserved.
Only for training and service purposes
LGE Internal Use Only
SECTION 3
ELECTRICAL
CONTENTS
ELECTRICAL TROUBLESHOOTING GUIDE
.....................................................................................3-2
1. SMPS TROUBLESHOOTING FLOW ......................................................................................................3-2
2. POWER CHECK FLOW ..........................................................................................................................3-4
3. SYSTEM OPERATION FLOW.................................................................................................................3-5
4. SYSTEM TEST FLOW ...........................................................................................................................3-6
DETAILS AND WAVEFORMS ON SYSTEM TEST AND DEBUGGING
...................................3-12
1. SYSTEM 27MHZ CLOCK, RESET, FLASH R/W SIGNAL ....................................................................3-12
2. SDRAM CLOCK ...................................................................................................................................3-14
3. TRAY OPEN/CLOSE SIGNAL ...............................................................................................................3-14
4. SLED CONTROL RELATED SIGNAL (NO DISC CONDITION)............................................................3-15
5. LENS CONTROL RELATED SIGNAL (NO DISC CONDITION) ..........................................................3-15
6. LASER POWER CONTROL RELATED SIGNAL (NO DISC CONDITION) ..........................................3-16
7. SPINDLE CONTROL WAVEFORM (NO DISC CONDITION) ...............................................................3-16
8. FOCUS ON WAVEFORM ......................................................................................................................3-17
9. TRACKING CONTROL RELATED SIGNAL (SYSTEM CHECKING) ....................................................3-18
10. MT1389L AUDIO COAXIAL OUTPUT (SPDIF) .....................................................................................3-19
11. MT1389L VIDEO OUTPUT WAVEFORM ..............................................................................................3-19
12. AUDIO OUTPUT FROM MT1389L ........................................................................................................3-20
CONNECTOR PICTURE
..........................................................................................................................3-21
1. ALL CONNECTOR PICTURE................................................................................................................3-21
2. CN201 CONNECTOR PICTURE...........................................................................................................3-22
3. CN202 CONNECTOR PICTURE...........................................................................................................3-22
4. CN601 CONNECTOR PICTURE...........................................................................................................3-23
5. CN602 CONNECTOR PICTURE...........................................................................................................3-23
6. CN605 CONNECTOR PICTURE...........................................................................................................3-24
7. CN701 CONNECTOR PICTURE...........................................................................................................3-24
BLOCK DIAGRAMS
..................................................................................................................................3-25
1. OVERALL BLOCK DIAGRAM ...............................................................................................................3-25
2. POWER (SMPS) BLOCK DIAGRAM.....................................................................................................3-26
3. SYSTEM BLOCK DIAGRAM .................................................................................................................3-27
4. SERVO BLOCK DIAGRAM ...................................................................................................................3-28
5. VIDEO BLOCK DIAGRAM.....................................................................................................................3-29
6. AUDIO BLOCK DIAGRAM.....................................................................................................................3-30
CIRCUIT DIAGRAMS
................................................................................................................................3-31
1. POWER (SMPS) CIRCUIT DIAGRAM ..................................................................................................3-31
2. SYSTEM (MPEG) CIRCUIT DIAGRAM.................................................................................................3-33
3. SERVO CIRCUIT DIAGRAM .................................................................................................................3-35
4. AV (JACK) CIRCUIT DIAGRAM ............................................................................................................3-37
5. 5.1CH CIRCUIT DIAGRAM (OPTION) ..................................................................................................3-39
6. KARAOKE & USB CIRCUIT DIAGRAM (OPTION)...............................................................................3-41
7. KEY CIRCUIT DIAGRAM ......................................................................................................................3-43
8. TIMER CIRCUIT DIAGRAM ..................................................................................................................3-45
• CIRCUIT VOLTAGE CHART
.........................................................................................................3-53
PRINTED CIRCUIT BOARD DIAGRAMS
...........................................................................................3-55
1. MAIN P.C.BOARD..................................................................................................................................3-55
2. POWER (SMPS) P.C.BOARD ...............................................................................................................3-57
3. 5.1CH & SCART P.C.BOARD (OPTIONAL PART)................................................................................3-57
4. KARAOKE & USB P.C.BOARD (OPTIONAL PART) .............................................................................3-59
5. KEY P.C.BOARD ...................................................................................................................................3-63
6. TIMER P.C.BOARD ...............................................................................................................................3-63