Power On Trouble Shooting - LG P705 Service Manual

4.10 Power ON Trouble Shooting

Power On sequence of P705 is :
Power key press -> KPD_PWR_N go to low -> PM8029 Power Up -> VREG_MSMC1_1.1V (L500),
VREG_MSMC2_1.1V (L501), VREG_MSME_1.8V (L502), VREG_P3_2.85V (C541), VREG_MSMA1_2.6V (C536),
VREG_MSMA2_1.2V (C532) VREG_TCXO_2.85V (C537) power ON -> Phone booting and PS_HOLD(D502) go
to High
Battery voltage higher than 3.70V(OCV)?
TP503 high to low when key press?
Check below power output
(VREG_MSMC1_1.1V)
(VREG_MSMC2_1.1V)
(VREG_MSME_1.8V)
(VREG_MSMA1_2.6V)
(VREG_MSMA2_1.2V)
(VREG_TCXO_2.85V)
Redownload SW image
LGE Internal Use Only
START
Yes
Yes
(VREG_P3_2.85V)
Yes
Is clock ok?
TP2 (X200) : 19.2M
Yes
No
Change or charging the Battery
No
Check correctly working power key
No
Change the Main board
No
Change the Main board
- 67 - Copyright © 2012 LG Electronics. Inc. All right reserved.
4. TROUBLE SHOOTING
Only for training and service purposes