LG LAS350B Service Manual page 14

2.1 ch sound bar

Owner's manual (29 pages)

Simple manual (4 pages)

Manual (4 pages)

Table of Contents

ONE POINT REPAIR GUIDE ............................................................................................................................ 3-2

1. NO POWER PROBLEM (PVDD) ............................................................................................................ 3-2

2. POWER ON ERROR .............................................................................................................................. 3-3

3. NO SOUND (PORTABLE FUNCTION) .................................................................................................. 3-4

4. NO BLUETOOTH .................................................................................................................................... 3-5

5. NO SOUND (OPTICAL) .......................................................................................................................... 3-6

ELECTRICAL TROUBLESHOOTING GUIDE ................................................................................................... 3-7

1. POWER SUPPLY CIRCUIT .................................................................................................................... 3-7

2. FRONT CIRCUIT .................................................................................................................................... 3-8

3. TEST & DEBUG FLOW ........................................................................................................................ 3-10

4. AMP PROTECTION .............................................................................................................................. 3-13

WAVEFORMS OF MAJOR CHECK POINT .................................................................................................... 3-14

1. CRYSTAL .............................................................................................................................................. 3-14

2. FLASH MEMORY ................................................................................................................................. 3-15

3. TACT KEY ............................................................................................................................................. 3-16

4. USB ....................................................................................................................................................... 3-17

5. REMOTE CONTROL ............................................................................................................................ 3-18

6. OPTICAL ............................................................................................................................................... 3-19

7. PORTABLE ........................................................................................................................................... 3-20

8. AUDIO PWM ......................................................................................................................................... 3-21

9. AUDIO AMP .......................................................................................................................................... 3-23

WIRING DIAGRAM .......................................................................................................................................... 3-25

BLOCK DIAGRAM .......................................................................................................................................... 3-27

CIRCUIT DIAGRAMS ...................................................................................................................................... 3-29

1. SMPS CIRCUIT DIAGRAM .................................................................................................................. 3-29

2. MAIN - DSP CIRCUIT DIAGRAM ......................................................................................................... 3-31

3. MAIN - POWER CIRCUIT DIAGRAM ................................................................................................... 3-33

4. MAIN - PWM & AMP CIRCUIT DIAGRAM ........................................................................................... 3-35

5. DISPLAY/ KEY/ USB CIRCUIT DIAGRAM ........................................................................................... 3-37

CIRCUIT VOLTAGE CHART ........................................................................................................................... 3-39

PRINTED CIRCUIT BOARD DIAGRAMS ....................................................................................................... 3-41

1. SMPS P. C. BOARD DIAGRAM ........................................................................................................... 3-41

2. MAIN P. C. BOARD DIAGRAM ............................................................................................................ 3-43

3. DISPLAY P. C. BOARD DIAGRAM ...................................................................................................... 3-45

4. KEY P. C. BOARD DIAGRAM .............................................................................................................. 3-45

5. USB P. C. BOARD DIAGRAM .............................................................................................................. 3-45

SECTION 3

ELECTRICAL

CONTENTS

3-1

Table of Contents