LG H990ds - Power Signal Troubleshooting

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reserved. Only training and service purposes
LGE Internal Use Only
3. TROUBLE SHOOTING
Checking Power signal (Battery connector, Power Key, PMIC Regulator, MSM, Memory)
Image Checking Flow
START
Battery voltage
higher than 3.3V?
Check POWER_KEY
Change or charging
the Battery (Battery connector)
contact Check
Press PWR Key
R8922 high to low?
YES
YES
YES
NO
NO
NO
Check Crystal
(X4100)
NO
PM8996/PMI8896의
VREG level Check?
PM8996(U4100) &
PMI8996(U4200) check
Check Clock?
YES
YES
Replace Main board
NO
Check MSM8996
(U2100)
NO
Check PM8996
(U4100)
Check MSM_RESIN_N high?
(C4248)
YES
Check MSM_PS_HOLD high?
(C4111)
Change Battery module,
Normal booting?
Change Battery module
YES
NO
R8922
(PWR
KEY)
U4100
(PM8996)
U4200
(PMI8996)
X4100
(19.2Mhz)
C4248
(PON_RESET_N)
C4111
(PS_Hold)
3.11 Power
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