Huawei P20 - Dialling; Basic Calling Functions

EML-L29V100R001 Advanced Maintenance Manual V2.1
INTERNAL
2019-6-25
Huawei Confidential
Page 45 of 67
4.13 Headset Failure
4.13.1 Maintenance Process
Headset failure
Is the headset faulty?
YES
Replace the headset
NO
Is the BTB
connector of the main FPC
fastened to the PCBA
properly?
YES
NO
Perform cross
verification. Is the PCBA
faulty?
NO
The components are
improperly installed in the
production line. Ask the PQE
to take corrective measures
NO
YES
Is the
resistance of the networks
normal?
YES
Perform cross
verification. Is the main FPC
faulty?
Replace the main FPC
NO
YES
Check the resistance of networks
HS_FB, HSR_TEST, HSL_TEST,
HS_MIC_TEST, and HS_GND_TEST
in sequence.
Replace the
corresponding resistor
or capacitor.
Is the DP HD
video normal?
YES
Replace U2201
NO
Is the USB device normal?
Replace U2102.
NO
YES
Replace U2101