3. TROUBLE SHOOTING
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Only for training and service purposes
LGE Internal Use Only
3.16 Power ON Troubleshooting
The main power source of LGD410 is provided by 1 chip which isPM8226. Since MSM8226 only powers up
normally when MSM8226 is properly powered therefore, PM8226is the actual one to take look at.
Power ON sequence of LGD410 is,PWR key press -> BAT_FET_N goes low-> GPIO8 High -> VREG_S3 High -> VREG_L6
High -> VREG_L12 High -> XBB_CLK -> PON_RESET_N goes high -> PS_HOLD High.
C4195
33p
0
R4105
100K
R4106
TOL=0.0
1
U4100
PM8226
117
129
61
169
88
42
31
39
13
44
17
62
6
5
63
120
123
112
77
101
100
119
108
102
85
CBL_PWR_N
KPD_PWR_N
OPT_2
OPT_1
PS_HOLD
RESIN_IN
PON_RESET_N
SPMI_CLK
SPMI_DATA
XO_THERM
GND_XOADC
XTAL_19M_IN
XTAL_19M_OUT
GND_XO_BUFF
GND_XO
BB_CLK1_EN
RF_CLK1
RF_CLK2
BB_CLK1
BB_CLK2
SLEEP_CLK1
VREF_BAT_THM
VREF_LPDDR
REF_BYP
GND_REF
0
R4108
VREF_LPDDR2
VREF_BAT_THERM
DNI
C4102
C410
1
DNI
C4100
1n
0.1u
C4106
R4107
0
R4104
10K
DNI
C4196
TP4103
R4112
0
R4110
0
TP4100
VREG_L12_1V8
0
R4114
X4100
1RAA19200AAA
19.2MHz
2
1
3
4
SENSOR XTAL2
XTAL1
GND1
WTR0_XO_IN
NFC_CLK_OUT
XO_G_TCXO
BB_CLK
SLEEP_CLK
BB_CLK_EN
MSM_PS_HOLD
JTAG_PS_HOLD
PM_KYPD_PWR_N
PMIC_SPMI_DATA
PMIC_SPMI_CLK
MSM_RESIN_N
Rev1,0) ESD
RevB
QCT Ref.J (11/5)
Please refer to 80-NC833-14 for more information.
BB_CLK has special layout and component requirements.
(05/30)
QCT Ref.checklist
(07/01)
TP3
TP5
TP4
TP2
TP1