LG S90QY - One Point Repair Guide; Power on Error

4-4
Copyright © 2022 LG Electronics Inc. All rights reserved.
Only for training and service purposes.
ONE POINT REPAIR GUIDE
1. POWER ON ERROR
Fundamental power check points.
1-1. 12 V
1) Check 12 VA at WL708.
2) If 12 V is not checked at the point, then find PVDD at pin2 of WIC703.
3) 1), 2) is NG, replace subwoofer board.
1-2. 3.3 VA
1) Check 3.3 VA at WL707.
2) If 3.3 VA is not checked at the point, then find 12 VA at pin3 of WIC705.
3) 1), 2) is NG, replace subwoofer board
< Subwoofer board top view >
< Subwoofer board top view >
WIC703
WIC703
WIC705
WIC705
3.3 VA
3.3 VA
12VA
12VA
PVDD
PVDD
12 VA
12 VA