Huawei P20 - Notification Panel and Status Bar

EML-L29V100R001 Advanced Maintenance Manual V2.1
INTERNAL
2019-6-25
Huawei Confidential
Page 31 of 67
4.5 Proximity/Ambient Light Sensor Failure
4.5.1 Maintenance Process
Light sensor failure
(automatic MMI)
Is it an l0005
failure?
Is the
touchscreen
transmittance
low?
Replace the front
cover assembly
Light sensor failure
(manual MMI)
Do the
PCBA and front cover
spring contact
properly?
Perform
cross verification. Is
the front cover assembly
normal?
Check whether the
spring is damaged
Replace the front
cover
Perform cross
verification. Is the PCBA
normal?
Are power
VOUT18(C2901) and
VOUT24(C2902)
normal?
Replace U1000
Check whether components on the I2C0
(C2903, C2904) circuit are defective
Yes
No
Yes
No
Yes
Yes
No
Yes
No
Yes