Power - LG -H815 Service Manual

3.11 Power

The out put frequency(19.2MHz) of XO(X4100) is used as the reference one of PM8994 internal VCO
Checking Flow
START
Voltage 3.4V ~ 4.4V?
NO
YES
POWER KEY ON
R11006 is LOW?
NO
YES
PM8994 is VREG level
NO
Check?
YES
CLOCK CHECK
(X4100)?
NO
YES
( )
PON_RESET_N TP4204
1.8V ?
CHECK
NO
YES
)
MSM_PS_HOLD(TP4105
?
High
NO
YES
TP1 Check?
NO
YES
Replace MAIN board
LGE Internal Use Only
Replace BATTERY
CN9100
(Battery connector)contact Check
POWER_KEY Check
U4100(PM8994 Check)
X4100 PIN CHECK(19.2Mhz)
U4100(PM8994 Check)
U2100(MSM8992 Check)
U3200(eMMC Check )
Main
Bottom
R11006
(PHONE_ON_N)
TP4105
U4100
(PS_Hold)
(PM8994)
CN9100
CN9100
Main
Top
TP1
U3200
(eMMCc_DATA_0)
(eMMC)
39
3. TROUBLE SHOOTING
Image
TP4204
(PON_RESET_N)
U2100
U4200
(MSM8992)
(PMI8994)
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reserved. Only training and service purposes
@Jaha
X4100