LG SP8YA - Page 45

3-12
Copyright © 2021 LG Electronics Inc. All rights reserved.
Only for training and service purposes.
ONE POINT REPAIR GUIDE
PROTECTION ERROR
No display or No Sound.
3-2. S(SHUT DOWN) PROTECTION
3-2-1. Solution
Replace AMP board.
3-2-2. How to troubleshoot (Countermeasure)
1) Check PVDD voltage (25 V) of IC700, IC701, IC702 pin29, 30, 31, 36, 37, 38.
- If PVDD voltage has 8.5 V under, refer to STEP 1-1.
2) Check GVDD, VDD voltage (12 V) of IC700, IC701, IC702 pin1, 2, 22.
- If GVDD, VDD voltage has 8.5 V under, refer to STEP 1-1.
3) Check impedance (4 Ω) of speaker unit.
- If impedance of speaker unit has 1 Ω under, replace speaker unit.
4) If check point 1), 2), 3) is OK, replace AMP board.
3-2-3. Service hint (Any picture / Remark)
< AMP board bottom view >
IC702
IC702
IC701
IC701
IC700
IC700