3-1
Copyright © 2008 LG Electronics. Inc. All right reserved.
Only for training and service purposes
LGE Internal Use Only
SECTION 3
ELECTRICAL
CONTENTS
LCD PART
........................................................3-2
LCD ELECTRICAL
TROUBLESHOOTING GUIDE
....................3-2
WIRING CONNECTION DIAGRAM
...........3-3
LCD PCB <---> KEY PCB, BACK LIGHT,
LCD PANNEL .....................................................3-3
INTERFACE DIAGRAM
.................................3-4
LCD PCB <---> KEY PCB INTERFACE.............3-4
BLOCK DIAGRAM
..........................................3-5
CIRCUIT DIAGRAMS
.....................................3-7
1. LCD I/F CIRCUIT DIAGRAM .........................3-7
2. PANEL I/F CIRCUIT DIAGRAM .....................3-9
3. FRONT KEY BOARD
CIRCUIT DIAGRAM .....................................3-11
4. LCD BACKLIGHT CIRCUIT DIAGRAM .......3-13
PRINTED CIRCUIT BOARD
DIAGRAMS
......................................................3-15
1. LCD P.C.BOARD..........................................3-15
2. FRONT KEY P.C.BOARD ............................3-15
3. BACK-LIGHT P.C.BOARD ...........................3-16
MAIN PART
....................................................3-19
MAIN ELECTRICAL
TROUBLESHOOTING GUIDE
..................3-19
1. POWER (DC-DC CONVERTER)
CIRCUIT.......................................................3-19
2. MPEG CIRCUIT ...........................................3-22
3. RF/SERVO CIRCUIT ...................................3-23
4. CHARGEING CIRCUIT................................3-26
DETAILS AND WAVEFORMS ON
SYSTEM TEST AND DEBUGGING
.........3-27
1. SYSTEM 27MHz CLOCK ............................3-27
2. SDRAM CLOCK...........................................3-27
3. DISC TYPE JUDGEMENT WAVEFORM.....3-28
4. FOCUS ON WAVEFORM ............................3-30
5. SPINDLE CONTROL WAVEFORM
(NO DISC CONDITION)...............................3-30
6. TRACKING CONTROL RELATED SIGNAL
(SYSTEM CHECKING) ................................3-31
7. LCD DRIVE IC(U701) SYSTEM CLOCK
(27MHz)........................................................3-32
8. ZR36966 VIDEO OUTPUT WAVEFORM ....3-32
9. AUDIO OUTPUT FROM AUDIO DAC .........3-33
WIRING CONNECTION DIAGRAMS
......3-34
1. OVERALL CONNECTION LAYOUT
DIAGRAM.....................................................3-34
2. WIRING CONNECTION DIAGRAM-1 .........3-35
3. WIRING CONNECTION DIAGRAM-2 .........3-36
INTERNAL BLOCK DIAGRAM OF ICs
..3-37
1. MOTOR DRIVE IC(AM5898N).....................3-37
2. LCD DRIVE IC(T103)...................................3-39
3. VOLUME CONTROLLER IC(PT2257).........3-43
4. SPEAKER AMP IC(PT2303) ........................3-44
5. MICOM IC(GT6319).....................................3-45
INTERFACE DIAGRAM
...............................3-47
MAIN <---> LCD PCB INTERFACE .................3-47
BLOCK DIAGRAMS
.....................................3-48
1. OVERALL BLOCK DIAGRAM......................3-48
2. POWER BLOCK DIAGRAM ........................3-49
3. MPEG BLOCK DIAGRAM ...........................3-50
4. DISC BLOCK DIAGRAM .............................3-51
5. AV BLOCK DIAGRAM..................................3-52
CIRCUIT DIAGRAMS
...................................3-53
1. MPEG CIRCUIT DIAGRAM .........................3-53
2. MEMORY CIRCUIT DIAGRAM....................3-55
3. OPU & MOTOR CIRCUIT DIAGRAM ..........3-57
4. AV CIRCUIT DIAGRAM ...............................3-59
5. CHARGE CIRCUIT DIAGRAM ....................3-61
6. MAIN KEY CIRCUIT DIAGRAM ..................3-63
CIRCUIT VOLTAGE CHART
......................3-65
1. IC VOLTAGE CHART...................................3-65
2. CAPACITOR VOLTAGE CHART..................3-66
PRINTED CIRCUIT
BOARD DIAGRAMS
.....................................3-67
1. MAIN P.C.BOARD........................................3-67
2. MAIN KEY P.C.BOARD................................3-67
3. MIS P.C.BOARD ..........................................3-69