3. TROUBLE SHOOTING
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3.16 Power ON Troubleshooting
The main power source of LGD618 is provided by 1 chip which is PM8226. Since MSM8226 only powers up normally
when MSM8226 is properly powered therefore, PM8226 is the actual one to take look at.
Power ON sequence of LGD618 is,
PWR key press -> BAT_FET_N goes low -> GPIO8 High -> VREG_S3 High -> VREG_L6 High -> VREG_L12 High -> BB_CLK ->
PON_RESET_N goes high -> PS_HOLD High.
VREG_S4_2P1
VREG_S3_1P35
VREG_S2_1P15
VREG_S1_1P15
C4135
22
u
6.3V
22
u
C4134
6.3V
C4136
47u
C4137
DNI
C4138
22u
22u
C4139
TP4(C4139)
CN10000
4
3
2
1
R10001
100
R10002
100
R10003
100
D10005
2
1
D10003
2
1
D10004
2
1
KEYPAD_SENSE_0
PM_KYPD_PWR_N
KEYPAD_SENSE_2
TP1(R10002)