U8655
Maintenance Manual
9 Principles and Failure Analysis
Issue 1.0 (2012-02-23)
Huawei Proprietary and Confidential
Copyright © Huawei Technologies Co., Ltd.
28
Y
Y
Reinstall the phone's
firmware. Is the problem
solved
N
N
N
N
N
N
Y
Y
Powe-on failure:
weak current
End
Is U201'output
Voltage normal
Y
Y
Does X301 have
32.768 kHz output?
Replace U601 and reinstall
The phone's firmware. Is the
Problem solved?
Y
Y
Replace U401
N
N
Replace U201
Replace X301
End
Excessive current
Excessive current is caused by short circuits. When excessive current occurs, to prevent
damage to components, do not connect the charger to the phone. Power-on failure due to
excessive current is usually the result of short-circuited VBAT circuit.
