LG DP450G Service Manual page 12

Manual (30 pages)

Table of Contents

.......................................................................................................................................................3-2

LCD ELECTRICAL TROUBLESHOOTING GUIDE

BLOCK DIAGRAM

.......................................................................................................................................3-3

CIRCUIT DIAGRAM

PRINTED CIRCUIT BOARD 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

4. CHARGING CIRCUIT ............................................................................................................................3-18

DETAILS AND WAVEFORMS ON SYSTEM TEST AND DEBUGGING

1. SYSTEM 27MHz CLOCK .......................................................................................................................3-19

2. SDRAM CLOCK .....................................................................................................................................3-19

3. MT1389 VIDEO OUTPUT WAVEFORM ................................................................................................3-20

4. AUDIO OUTPUT FROM AUDIO DAC ....................................................................................................3-20

BLOCK DIAGRAMS

1. OVERALL BLOCK DIAGRAM ................................................................................................................3-21

2. POWER BLOCK DIAGRAM ...................................................................................................................3-22

3. SERVO BLOCK DIAGRAM ....................................................................................................................3-23

4. SYSTEM BLOCK DIAGRAM ..................................................................................................................3-24

5. A/V 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 I/F CIRCUIT DIAGRAM ..................................................................................................................3-37

7. KEY CIRCUIT DIAGRAM .......................................................................................................................3-39

• CirCuit VoltaGe CHart

PRINTED CIRCUIT BOARD DIAGRAMS

1. MAIN P.C.BOARD ..................................................................................................................................3-45

2. KEY P.C.BOARD ...................................................................................................................................3-49

SECTION 3

ELECTRICAL

CONTENTS

.....................................................................................................................................3-5

................................................................................................3-7

..................................................................................................................................3-21

................................................................................................................................3-27

................................................................................................................3-41

...........................................................................3-2

.......................................................................3-11

...........................................................................................3-45

3-1