LG DP372B Service Manual page 12

ELECTRICAL TROUBLESHOOTING GUIDE
1. POWER CHECK FLOW.........................................................................................................................3-2
2. SYSTEM OPERATION FLOW ...............................................................................................................3-3
3. SYSTEM TEST FLOW ..........................................................................................................................3-4
DETAILS AND WAVEFORMS ON SYSTEM TEST AND DEBUGGING
1. SYSTEM 27MHZ CLOCK, RESET, FLASH SCK SIGNAL. .................................................................3-10
2. SDRAM CLOCK ...................................................................................................................................3-12
3. TRAY OPEN/CLOSE SIGNAL..............................................................................................................3-12
4. SLED CONTROL RELATED SIGNAL ..................................................................................................3-13
5. LASER POWER CONTROL RELATED SIGNAL.................................................................................3-14
6. SPINDLE CONTROL WAVEFORM......................................................................................................3-14
7. FOCUS ON WAVEFORM.....................................................................................................................3-15
8. TRACKING CONTROL RELATED SIGNAL(System checking) ...........................................................3-16
9. 1389DE/LP VIDEO OUTPUT WAVEFORM .........................................................................................3-17
10. AUDIO OUTPUT FROM 1389DE/LP .................................................................................................3-17
WIRING CONNECTION DIAGRAMS
1. WIRING CONNECTION DIAGRAM-1..................................................................................................3-18
2. WIRING CONNECTION DIAGRAM-2..................................................................................................3-19
BLOCK DIAGRAMS
1. OVERALL BLOCK DIAGRAM ..............................................................................................................3-20
2. POWER BLOCK DIAGRAM.................................................................................................................3-21
3. SERVO BLOCK DIAGRAM..................................................................................................................3-22
4. SYSTEM BLOCK DIAGRAM................................................................................................................3-23
5. AV BLOCK DIAGRAM ..........................................................................................................................3-24
6. LCD BLOCK DIAGRAM .......................................................................................................................3-25
CIRCUIT DIAGRAMS
1. MPEG CIRCUIT DIAGRAM .................................................................................................................3-27
2. MEMORY CIRCUIT DIAGRAM ............................................................................................................3-29
3. OPU & MOTOR CIRCUIT DIAGRAM ..................................................................................................3-31
4. AV CIRCUIT DIAGRAM........................................................................................................................3-33
5. CHARGE CIRCUIT DIAGRAM.............................................................................................................3-35
6. LCD IF CIRCUIT DIAGRAM.................................................................................................................3-37
7. AUDIO CIRCUIT DIAGRAM.................................................................................................................3-39
8. KEY CIRCUIT DIAGRAM .....................................................................................................................3-41
9. LCD KEY CIRCUIT DIAGRAM.............................................................................................................3-43
CIRCUIT VOLTAGE CHART
PRINTED CIRCUIT BOARD DIAGRAMS
1. MAIN P.C.BOARD ................................................................................................................................3-49
2. LCD P.C.BOARD ..................................................................................................................................3-53
3. INVERTER P.C.BOARD .......................................................................................................................3-53
4. KEY P.C.BOARD ..................................................................................................................................3-53
Copyright © 2008 LG Electronics. Inc. All right reserved.
Only for training and service purposes
SECTION 3
ELECTRICAL
CONTENTS
..................................................................................................3-18
.................................................................................................................................3-20
..............................................................................................................................3-27
..........................................................................................................3-45
...................................................................................3-2
.........................................................................................3-49
3-1
.................................3-10
LGE Internal Use Only