U9500 Maintenance Guide
9 Troubleshooting
Issue 1.2 (2012-6-30)
Huawei Proprietary and Confidential
Copyright © Huawei Technologies Co., Ltd.
45
Figure 9-8
Components that might be damaged
U901 PM chip
U301/U301_POP Main
chip/DDR
U1102 8G EMMC
Handling Process
Figure 9-9 shows the process for handling the weak current power-on failure.
Figure 9-9
Handling process for the weak current power-on failure
N
Resolder or replace U901.
Resolder or replace
VCXO900 and U501.
Resolder or replace
U901.
Check if other circuits, especially
the U902 and U3201, are in
good condition.
After the phone is connected to a USB
charger or fake battery and the Power key is
pressed, a low current is detected, and the
phone fails to be powered on.
Is the power output of
elements on the U901
normal?
Are the 26 MHz VCXO and clock
buffer signals normal?
Y
N
Is the H_SYS_NRESPWR signal
normal?
Y
Resolder or replace
VCXO900 and U501.
N
Y
N
