Huawei P20 - Home Screen Management

EML-L29V100R001 Advanced Maintenance Manual V2.1
INTERNAL
2019-6-25
Huawei Confidential
Page 35 of 67
4.7 Compass Failure
4.7.1 Maintenance Process
Compass failure
No
Does U2604
have cosmetic defects or soldering
issues?
Replace or re-solder
U2604
Yes
No
Are all the sensors
(photoreceptor, accelerometer,
and gyroscope) on the I2C0
circuit abnormal?
Replace U2601
Yes
No
Do any
components on the I2C0
circuit have cosmetic defects or
soldering issues?
Replace or re-solder
the faulty components
No
Yes
Is the sensor
power supply normal (C2603)?
If there are no
soldering issues,
replace U1000
Is the I2C0 signal
normal (J2901)?
If there are no
soldering issues,
replace U300
Replace the faulty
sensor
No
Yes
Yes
No
Ask PCBA process
engineers to analyze
the cause
Because all sensor I2Cs are mounted to the I2C0 circuit, choose a proper network for the test.