LG DP270B Service Manual page 10

LCD PART
...................................................................................................................................................3-2
LCD ELECTRICAL TROUBLESHOOTING GUIDE
BLOCK DIAGRAM
CIRCUIT DIAGRAM
PRINTED CIRCUIT DIAGRAM
MAIN PART
...............................................................................................................................................3-11
MAIN ELECTRICAL TROUBLESHOOTING GUIDE
1. POWER (DC-DC CONVERTER) CIRCUIT..........................................................................................3-11
2. MPEG CIRCUIT ...................................................................................................................................3-14
3. RF/SERVO CIRCUIT............................................................................................................................3-15
DETAILS AND WAVEFORMS ON SYSTEM TEST AND DEBUGGING
1. SYSTEM 27MHZ CLOCK, RESET & FLASH R/W SIGNAL................................................................3-19
2. SDRAM CLOCK ...................................................................................................................................3-19
3. DISC TYPE JUDGEMENT WAVEFORM .............................................................................................3-20
4. FOCUS ON WAVEFORM.....................................................................................................................3-22
5. SPINDLE CONTROL WAVEFORM (NO DISC CONDITION)..............................................................3-22
6. TRACKING CONTROL RELATED SIGNAL (SYSTEM CHECKING) ..................................................3-23
7. MT1389 AUDIO OPTICAL AND COAXIAL OUTPUT (ASPDIF) ..........................................................3-24
8. MT1389 VIDEO OUTPUT WAVEFORM ..............................................................................................3-24
9. AUDIO OUTPUT FROM AUDIO DAC..................................................................................................3-25
WIRING CONNECTION DIAGRAMS
1. WIRING CONNECTION DIAGRAM 1 ..................................................................................................3-26
2. WIRING CONNECTION DIAGRAM 2 ..................................................................................................3-27
BLOCK DIAGRAMS
1. OVERALL BLOCK DIAGRAM ..............................................................................................................3-28
2. POWER BLOCK DIAGRAM.................................................................................................................3-29
3. SERVO BLOCK DIAGRAM..................................................................................................................3-30
4. SYSTEM BLOCK DIAGRAM................................................................................................................3-31
5. AV BLOCK DIAGRAM ..........................................................................................................................3-32
CIRCUIT DIAGRAMS
1. MPEG CIRCUIT DIAGRAM .................................................................................................................3-33
2. MEMORY CIRCUIT DIAGRAM ............................................................................................................3-35
3. OPU & MOTOR CIRCUIT DIAGRAM ..................................................................................................3-37
4. AV CIRCUIT DIAGRAM........................................................................................................................3-39
5. CHARGE CIRCUIT DIAGRAM.............................................................................................................3-41
6. FM-TX (OPTION) CIRCUIT DIAGRAM................................................................................................3-43
7. PANEL I/F CIRCUIT DIAGRAM ...........................................................................................................3-45
8. MENU KEY CIRCUIT DIAGRAM .........................................................................................................3-47
9. FRONT KEY CIRCUIT DIAGRAM .......................................................................................................3-49
• CIRCUIT VOLTAGE CHART
PRINTED CIRCUIT DIAGRAMS
1. MAIN P.C.BOARD ................................................................................................................................3-55
2. KEY MENU P.C.BOARD ......................................................................................................................3-59
3. KEY FRONT P.C.BOARD.....................................................................................................................3-59
SECTION 3
ELECTRICAL
CONTENTS
......................................................................................................................................3-5
...................................................................................................................................3-7
...............................................................................................................3-9
..................................................................................................3-26
.................................................................................................................................3-28
..............................................................................................................................3-33
..............................................................................................................3-51
..........................................................................................................3-55
.........................................................................3-3
.....................................................................3-11
3-1
.................................3-19