U8655
Maintenance Manual
9 Principles and Failure Analysis
Issue 1.0 (2012-02-23)
Huawei Proprietary and Confidential
Copyright © Huawei Technologies Co., Ltd.
31
Troubleshooting Charging Failure
Charging f ailure
Is J901 poorly
soldered?
Re-solder J901
Is the battery's in good
contact with the battery
connector?
End
Does VPH_PWR have
voltages?
Repair or replace
J902
Replace U901
N
Y
Y
Y
N
N
Is the battery damaged?
Replace the
battery
Y
N
Y
Y
Is there voltage difference
between Q202' pin 2 and
pin 3?
Replace Q202
N
Is the charger working
properly?
Replace the
charger
N
Y
9.3 RF Unit
9.3.1 RF Failure
Troubleshooting Transmission Failure
GSM/DCS transmission failure
Before starting the following process, make sure that the USIM card and the antenna are well
connected.