Rf Failure (Tds/Lte); Maintenance Process (Transmission) - Huawei P20 Maintenance Manual

4.19 RF Failure (TDS/LTE)

4.19.1 Maintenance Process (Transmission)

rectified after the software is updated to
output RF signals of U3701, U3401, and
U3501 based on the non-signaling transmission of the
frequency band. Are the signals
on the corresponding circuit based on the
abnormal frequency band. Is the failure
Is the failure rectified after the related
2019-6-25
EML-L29V100R001 Advanced Maintenance Manual V2.1
LTE RF transmission failure
Are the
wired specifications
normal?
No
Is the failure
the latest version?
No
Is the RF PA power
supply normal?
Yes
Spot-check the
normal?
Yes
Replace the filter
rectified?
No
circuit is replaced?
No
Replace U3801
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Check whether the RF
Yes
connection cable is normal
and whether the antenna
spring is in good contact
Yes
No
No
Replace U3401, U3501,
Yes
Yes
Yes
No
Replace U3301
INTERNAL
End
Replace U3202
and U3701
End
End
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