Low Current (Dc Power Supply) - Huawei U9200 Maintenance Manual

Figure 9-3 Large current check process

9.2.2 Low Current (DC Power Supply)

Low current is usually caused by short circuit on the PM chip or system startup failure, which
is due to a faulty main chip or memory chip. The low current ranges from 20 mA to several
hundred mA.
(2012-06-13)
U9200 Maintenance Manual
After the phone is connected to a
USB charger or simulated battery,
and the power key is pressed, a
large current is detected.
Is the VBAT circuit
shorted?
Y
Are the circuit
elements of the
battery connector
shorted?
N
Is the U1901,
U1301, U4801, or
U4704 shorted?
N
Are other circuits,
especially those close to
the connector, shorted?
Huawei Proprietary and Confidential
Copyright © Huawei Technologies Co., Ltd.
N
Check whether the
VPH_PWR circuit is
Y
Resolder or
replace the
shorted element.
Check if other circuits,
Resolder or
especially those close to
Y
replace the
the connector, are
shorted element.
shorted.
INTERNAL
shorted.
Is the current
Y
recovered after the
U1901 is soldered?
N
Page 47 of 80
End