LG BH5140S Service Manual page 47

2. NO BOOTING WHEN YOU TURN THE UNIT ON, NO MESSAGE OR
"PLEASE WAIT" ON FRONT PANEL
When you turn on your set, it will blank / no message or "PLEASE WAIT" display on front panel, and
it will not boot-up.
2-4. IC153 (NO 1.5 V)
2-4-1. Solution
Replace IC153 on MAIN board.
2-4-2. How to troubleshoot (Countermeasure)
1) Please check 1.5 V of C174 on MAIN board.
2) If 1.2 V voltage doesn't come out, check IC153 pin13 (VCC_14VA).
3) If VIN2 (pin13) of IC153 is not 14 VA.
First, check CN150 and if there's no defective component, please check SMPS board.
4) After fixing it, if the set is still not booting :
Check L153 and finally check IC153 or replace.
5) After fixing it, if the set is still not booting :
- Refer to the next page for checking another power source. (3.3 V, 1.2 V)
- Check Crystal X501 refer to item 2-5.
- Check NAND Flash IC (IC504) refer to item 2-6.
- Check DDR IC (IC502, IC503) refer to item 2-7.
- Check MT8560 IC (IC501) refer to item 2-8.
2-4-3. Service hint (Any picture / Remark)
ONE POINT REPAIR GUIDE
L153
C174
< Main board top view >
2-32
IC153