LG NP8540 Service Manual page 32

IF NOT BOOTING WHEN YOU TURN ON THE SET.
3-5. IC503, IC504 (DDR IC)
3-5-1. Solution
Replace IC503, IC504 on main board.
3-5-2. How to troubleshoot (Countermeasure)
1) Check 0.75 V of DDR3_VREF (Point 1).
If voltage is abnormal follow the stage 3-1-2 at the previous page.
2) Check 0.75 V of DDR3_VREF (Point 2).
If voltage is abnormal follow the stage 3-1-2 at the previous page.
3) Check 1.5 V of C5A5.
4) If 1.5 V and 0.75 V are abnormal, check the around parts. (C5A5, C5A6, R555, R556)
5) If there's no defective component, follow the stage 3-1-2 at the previous page.
6) When you followed above step but it doesn't work, replace the IC503, IC504.
3-5-3. Service hint (Any picture / Remark)
Point 2 Point 2
ONE POINT REPAIR GUIDE
Point 1 Point 1
IC503 IC503
IC504 IC504
< Main board top view >
3-9
C5A5 C5A5