Figure 9-3 Troubleshooting Process For No Current - Huawei U8815 Maintenance Manual

U8815
Maintenance Manual
3.
4.
Figure 9-3 shows the troubleshooting process for no current.

Figure 9-3 Troubleshooting process for no current

5.
Figure 9-4 shows the troubleshooting process for weak current.
Issue 1.0 (2012-02-13)
High current: Connect your handset to DC power supply. Press the On key. The
displayed current is greater than 300 mA.
If your handset cannot be powered on, locate the fault by observing the power-on current
of DC power supply.
No current
Power-on
failure
Connect the handset to
a fake battery and a
maintenance power
supply and press On to
check the current.
No current
Is the copper foil of
the On key is
oxygenated?
N
Test whether the
VPH_PWR voltage is
normal. The maintenance
power voltage ranges
from 3.4 to 4.2 V DC.
Y
Does the clock
function properly?
Y
Return the
handset to the
factory for repair.
Weak current
Huawei Proprietary and Confidential
Copyright © Huawei Technologies Co., Ltd.
Clean the
Y
N
Check U201.
N
Check the X401
and U3101clocks.
9 Principles and Failure Analysis
On key.
24