LG SJ2 Service Manual

3-1
SECTION 3
ELECTRICAL
CONTENTS
ONE POINT REPAIR GUIDE ............................................................................................................................ 3-2
1. NO POWER PROBLEM ......................................................................................................................... 3-2
2. SPEAKER NO AUDIO OUTPUT ............................................................................................................ 3-3
3. USB NO DETECT ................................................................................................................................... 3-4
ELECTRICAL TROUBLESHOOTING GUIDE ................................................................................................... 3-5
1. SMPS POWER CIRCUIT ........................................................................................................................ 3-5
2. KEY PART .............................................................................................................................................. 3-7
3. POWER AMP PART ............................................................................................................................... 3-8
4. PORTABLE FUNCTION ......................................................................................................................... 3-9
5. OPTICAL FUNCTION ........................................................................................................................... 3-10
6. USB PART ............................................................................................................................................ 3-11
WAVEFORMS OF MAJOR CHECK POINT .................................................................................................... 3-12
1. CRYSTAL .............................................................................................................................................. 3-12
2. AMP IC .................................................................................................................................................. 3-13
3. RESET IC .............................................................................................................................................. 3-14
4. AMP FAULT .......................................................................................................................................... 3-15
WIRING DIAGRAM .......................................................................................................................................... 3-17
BLOCK DIAGRAM .......................................................................................................................................... 3-19
CIRCUIT VOLTAGE CHART ........................................................................................................................... 3-21
PRINTED CIRCUIT BOARD DIAGRAMS ....................................................................................................... 3-23
1. SMPS P. C. BOARD DIAGRAM ........................................................................................................... 3-23
2. MAIN P. C. BOARD DIAGRAM ............................................................................................................ 3-25
3. KEY P. C. BOARD DIAGRAM .............................................................................................................. 3-27
4. LED P. C. BOARD DIAGRAM .............................................................................................................. 3-28

LG SJ2 Specifications

General

Style	Wireless Soundbar
Color	Black
Channels	2.1
Total Power	160 W
Speaker Units	-
Internal Memory	-
Radio Tuner	-
Wireless Connectivity	Bluetooth
Interface Connectors	Optical Input 1 ea
Sound Modes	Sports
Max Sound Pressure Level (SPL)	-
Signal to Noise Ratio	-
Frequency Response	-
Features	Crystal Amplifier Pro
Audio Processing	-
Water / Dust resistance	-
Power Supply	~ 50/60Hz
Power Consumption	-
Battery Life	-
Battery Capacity	-

Weight and Dimensions

Depth	3.9 in
Height	2.2 in
Width	25.9 in
Net Weight	3.75 lbs