LG SPH4B-W Service Manual

4-1
Copyright © 2021 LG Electronics Inc. All rights reserved.
Only for training and service purposes.
SECTION 4
WIRELESS SUBWOOFER PART
CONTENTS
ONE POINT REPAIR GUIDE ............................................................................................................................ 4-2
1. NO POWER PROBLEM (PVDD) ............................................................................................................ 4-2
2. POWER ON ERROR .............................................................................................................................. 4-3
3. POWER ON ERROR .............................................................................................................................. 4-4
4. WIRELESS CONNECTION .................................................................................................................... 4-5
WAVEFORMS OF MAJOR CHECK POINT ...................................................................................................... 4-6
1. VOLTAGE ............................................................................................................................................... 4-6
2. AMP VOLTAGE ...................................................................................................................................... 4-7
3. PWM ....................................................................................................................................................... 4-8
4. LED ......................................................................................................................................................... 4-9
WIRING DIAGRAM .......................................................................................................................................... 4-11
BLOCK DIAGRAM .......................................................................................................................................... 4-13
PRINTED CIRCUIT BOARD DIAGRAMS ....................................................................................................... 4-15
1. WOOFER SMPS P. C. BOARD ............................................................................................................ 4-15
2. WOOFER AMP P. C. BOARD .............................................................................................................. 4-17
3. WOOFER KEY P. C. BOARD ............................................................................................................... 4-17

LG SPH4B-W Specifications

General

Brand	LG
Model	SPH4B-W
Category	Speaker System
Language	English