Receiver Failure; Maintenance Process - Huawei P20 Maintenance Manual

4.10 Receiver Failure

4.10.1 Maintenance Process

Noise
The receiver
foam is not in
position. Install
it again
2019-6-25
EML-L29V100R001 Advanced Maintenance Manual V2.1
Receiver failure
There is
no sound or
the sound is
too low
Perform cross
verification. Is the PCBA
normal?
Are
EARN and EARP
short-circuited to the ground?
Is the circuit open-
circuited?
Use an
X-ray machine for the
check. Do L2502 and L2503
have soldering
issues?
Ask PCBA process
engineers to
analyze the cause
Huawei Confidential
Yes
No
Is the receiver
resistance normal (about 30
ohms)?
No
Yes
No
Yes
It is suspected that
Codec U2201 is
faulty. Replace U2201
INTERNAL
No
Replace the receiver.
Send the faulty receiver
to the manufacturer for
analysis
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