U8185
Maintenance Manual
9 Principles and Failure Analysis
Issue 1.0 (2012-03-23)
Huawei Proprietary and Confidential
Copyright © Huawei Technologies Co., Ltd.
22
Replace J902
N
Power-on failure:
no current
Is the battery
connector J902
normal?
Replace Q201
N
Is Q201 normal?
Y
Re-solder or replace
U201
Y
Weak current
End
Y
Power-on failure:
weak current
Re-install the phone's
software. Is the problem
solved?
Is U201's output
voltage normal?
Replace U201
N
N
Replace U401
N
Does X301 have
32.768 kHz output?
Replace U601 and re-install
the phone's software. Is the
problem solved?
Y
Replace X301
N
End
Y
Y