LG LG-H815 - Power Troubleshooting

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reserved. Only training and service purposes
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3. TROUBLE SHOOTING
The out put frequency(19.2MHz) of XO(X4100) is used as the reference one of PM8994 internal VCO
3.11 Power
Image
Main
Bottom
Checking Flow
Voltage 3.4V ~ 4.4V?
POWER_KEY Check
Replace BATTERY
CN9100
(Battery connector)contact Check
POWER KEY ON
R11006 is LOW?
YES
NO
NO
NO
NO
U4100(PM8994 Check)
PON_RESET_N
(
TP4204
)
1.8V
CHECK
?
YES
U2100(MSM8992 Check)
MSM_PS_HOLD(TP4105
)
High
?
YES
NO
PM8994 is VREG level
Check?
U4100(PM8994 Check)
CLOCK CHECK
(X4100)?
X4100 PIN CHECK(19.2Mhz)
YES
NO
YES
YES
U3200(eMMC Check )
TP1 Check?
NO
YES
START
Replace MAIN board
Main
Top
U4100
(PM8994)
CN9100
U3200
(eMMC)
U2100
(MSM8992)
U4200
(PMI8994)
TP4105
(PS_Hold)
R11006
(PHONE_ON_N)
CN9100
X4100
TP4204
(PON_RESET_N)
TP1
(eMMCc_DATA_0)
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