LG S75A1-D User Manual

2-9
ONE POINT REPAIR GUIDE
8. IF THE SET DOESN’T BOOTING WHEN YOU TURN ON THE SET.
8-1. IC300 (NO 1.5 V / 1.2 V)
8-1-1. Solution
Replace IC300 on MAIN board.
8-1-2. How to troubleshoot (Countermeasure)
1) Please check 5.3 VA of L300 (VIN).
2) If 5.3 VA is abnormal, follow the stage 2-1 (IC308).
3) If 5.3 VA is OK, but 1.5 V is abnormal at the IC300 (pin9, pin10), check the DCDC_12_15_CTRL’s level (R306).
If level is high, check the around parts (R311, R312, R313) and if there’s no defective component, replace IC300.
If the DCDC_12_15_CTRL level is Low, follow the stage 9-1 (IC100).
4) If 5.3 VA is OK, but 1.2 V is abnormal at the IC300 (pin11, pin12), check the DCDC_12_15_CTRL’s level (R307).
If level is high, check the around parts (R309, R310) and if there’s no defective component, replace IC300.
If the DCDC_12_15_CTRL level is Low, follow the stage 9-1 (IC100).
8-1-3. Service hint (Any picture / Remark)
< MAIN board top view >
IC300
IC300

LG S75A1-D Specifications

General

Brand	LG
Model	S75A1-D
Category	Speakers
Language	English