U9200 Maintenance Manual
INTERNAL
(2012-06-13)
Huawei Proprietary and Confidential
Copyright © Huawei Technologies Co., Ltd.
Page 73 of 80
9.22 GSM RF Receiving Failure
Figure 9-30
GSM RF receiving failure troubleshooting process
GSM RF receiving failure
Is the RF index
recovered after you
update the software?
Y
End
N
Is the power supply of the
RF circuit normal?
N
Replace the
U4802.
Y
Is the fault rectified after you
replace the U4703 and U4702
respectively?
Y
End
N
Replace the U3801.
Is the fault rectified
after you replace the
U4701?
Y
End
N
Is the RF index normal?
N
Y
Check if the RF
cable is in good
condition and the
antenna clip in
good contact.
Is the fault rectified after you replace
the matching circuit considering the
unfavorable frequency band?
Y
End
N
