Charging Management Circuits - Huawei U8860 Maintenance Manual

U8860
Maintenance Manual

9.2.2 Charging Management Circuits

Circuit schematic diagram
The power supply of MSM8255 supports two external charging modes: charger mode and
USB mode.
The schematic diagram is shown as follows:
Issue 1.0 (2011-11-14)
Power-on failure-excessive
current
Is the VBAT ground short-circuited?
Y
Is problem solved after the RF PA
(U3402/U3803/U3501) is removed
successively?
N
Are the circuit of the battery connection
components short-circuited?
N
Replace U301.
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9 Principles and Troubleshooting
Check the VPH_PWR
N
circuit and the PM
output circuit.
Y
Replace the faulty
components.
Y
Replace the faulty
components.
37