LG SPM2 - Page 39

3-12
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ONE POINT REPAIR GUIDE
PROTECTION ERROR
No display or No Sound.
3-2. S(SHUT DOWN) PROTECTION
3-2-1. Solution
Replace MAIN board.
3-2-2. How to troubleshoot (Countermeasure)
1) Check AMP_PVDD voltage (20 V) of IC501, IC502 pin37, 48.
- If AMP_ PVDD voltage has no power, check to Q801 & SMPS.
2) Check AMP+3V3(3.3V) of IC501, IC502 pin8, 23.
- If AMP+3V3 voltage has no power, check to IC805 & Q808.
3) Check impedance (Front 6 Ω, Woofer 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 MAIN board.
3-2-3. Service hint (Any picture / Remark)
< MAIN board top view >
IC501
IC501
IC502
IC502