Huawei P20 - Troubleshooting; Charging Failure; Maintenance Process

EML-L29V100R001 Advanced Maintenance Manual V2.1
INTERNAL
2019-6-25
Huawei Confidential
Page 22 of 67
4 Troubleshooting
4.1 Charging Failure
4.1.1 Maintenance Process
Figure 4-1 Troubleshooting flowchart
Charging failure
Is the
battery damaged
or bulged? Is the
battery FPC
scratched?
Replace the
battery
Yes
Is the
battery connector
damaged on the
appearance?
No
Perform cross
verification. Is the
charger normal?
Replace the
charger
No
Perform cross
verification. Is the
charger normal?
Replace the
charging cable
No
Are the
voltages of VCHG_USB
and VCHG_USB_
CONN 5 V?
NoYes
The voltage
of VCHG_USB
is 0 V and that of
VCHG_USB_CONN is 5 V.
Is a direct charger
used?
Yes
Replace
U2101
No
Do I2C6_SCL
and I2C6_SDA have
signals?
Check whether U1602 and U300 are
soldered properly. If no, re-solder them.
If yes, replace the chips
Replace the
connector
Yes
Yes
No
No
No
If the voltages are
both 0 V, check
whether the USB
connector and FPC
on the subsidiary
board are damaged.
If so, replace them
Replace U1602
Replace
U1801