LG DK676X Service Manual page 11

ELECTRICAL TROUBLESHOOTING GUIDE
1. Power check flow.....................................................................................................................3-2
2. System operation flow ............................................................................................................3-3
3. Test & debug flow ....................................................................................................................3-4
4. KARAOKE Flow (KARAOKE MODEL ONLY) .......................................................................3-10
DETAILS AND WAVEFORMS ON SYSTEM TEST AND DEBUGGING
1. SYSTEM 27MHz CLOCK, RESET, FLASH R/W SIGNAL. ....................................................3-11
2. SDRAM CLOCK ......................................................................................................................3-13
3. TRAY OPEN/CLOSE SIGNAL ................................................................................................3-13
4. SLED CONTROL RELATED SIGNAL(NO DISC CONDITION) .............................................3-14
5. LENS CONTROL RELATED SIGNAL(NO DISC CONDITION) .............................................3-14
6. LASER POWER CONTROL RELATED SIGNAL(NO DISC CONDITION) ............................3-15
7. DISC TYPE JUDGEMENT WAVEFORM ................................................................................3-15
8. FOCUS ON WAVEFORM........................................................................................................3-17
9. SPINDLE CONTROL WAVEFORM(NO DISC CONDITION ...................................................3-18
10. TRACKING CONTROL RELATED SIGNAL(System checking).........................................3-19
11. MT1389E AUDIO OPTICAL AND COAXIAL OUTPUT (SPDIF) ..........................................3-20
12. MT1389E VIDEO OUTPUT WAVEFORM .............................................................................3-20
13. AUDIO OUTPUT FROM AUDIO MT1389E...........................................................................3-21
BLOCK DIAGRAMS
1. OVERALL BLOCK DIAGRAM................................................................................................3-22
2. POWER(SMPS) BLOCK DIAGRAM.......................................................................................3-23
3. SERVO BLOCK DIAGRAM ....................................................................................................3-24
4. MPEG & MEMORY BLOCK DIAGRAM .................................................................................3-25
5. VIDEO & AUDIO BLOCK DIAGRAM .....................................................................................3-26
CIRCUIT DIAGRAMS
1. POWER(SMPS) CIRCUIT DIAGRAM.....................................................................................3-27
2. SYSTEM CIRCUIT DIAGRAM ................................................................................................3-29
3. SERVO CIRCUIT DIAGRAM ..................................................................................................3-31
4. AV/JACKCIRCUIT DIAGRAM.................................................................................................3-33
5. TIMER CIRCUIT DIAGRAM ( 3 TOOL ONLY ) ......................................................................3-35
6. TIMER CIRCUIT DIAGRAM ( 4 TOOL ONLY ) ......................................................................3-37
7. TIMER CIRCUIT DIAGRAM ( 6 TOOL ONLY ) ......................................................................3-39
8. TIMER CIRCUIT DIAGRAM ( 7 TOOL ONLY ) ......................................................................3-41
9. TIMER CIRCUIT DIAGRAM ( 8 TOOL ONLY ) ......................................................................3-43
10. KARAOKE CIRCUIT DIAGRAM (KARAOKE MODEL ONLY) ............................................3-45
• CIRCUIT VOLTAGE CHART ....................................................................................................3-47
PRINTED CIRCUIT DIAGRAMS
1. MAIN P.C.BOARD ...................................................................................................................3-49
2. KEY P.C.BOARD.....................................................................................................................3-51
3. TIMER P.C.BOARD .................................................................................................................3-51
4. SMPS P.C.BOARD (360mm ONLY) .......................................................................................3-53
5. SMPS P.C.BOARD (430mm ONLY) .......................................................................................3-53
6. JACK P.C.BOARD (OPTIONAL PART)..................................................................................3-53
7. KARAOKE P.C.BOARD (KARAOKE MODEL ONLY) ...........................................................3-54
SECTION 3
ELECTRICAL
CONTENTS
..................................................................................................................3-22
................................................................................................................3-27
............................................................................................3-49
......................................................................3-2
3-1
....................3-11