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S7-PRO Maintenance Manual (Basic Version V2.1)
INTERNAL
2012-07-20
Huawei Proprietary and Confidential
Copyright © Huawei Technologies Co., Ltd.
Page 77 of 97
9.13.2 Maintenance Procedures for GSM Receive Failure
Yes
No
Y
Replace U21
Check the input signal, output signal,
logic control signal, and power supply.
If any exception is found, replace U46
Check whether the antenna switch
(U46) and the GSM receive channel
work normally
No
Y
No
Check the power supply for U23. If any
exception is found, replace U23
Check whether the input and
output signals of duplexers
(U21) (GSM850) are normal
Power the board
on
End
Yes
Check whether
QTR8615 (U23) works
normally
Maintenance procedures
Yes