Huawei P20 Maintenance Manual page 13

No. Designator
3 U1000
4 U1101
5 U1201
6 X1201
7 U1301
8 U1400
9 J1501
10 U1602
11 U1701
12 U1702
13 J1701
14 U1801
15 U1901
16 U1902
17 J2001
2019-6-25
EML-L29V100R001 Advanced Maintenance Manual V2.1
Description
Main system
PMU HI6421
Sub-PMU, which
provides power
for SOC
peripheral
devices' I/O
PMU buckboost
System 38.4
MHz clock
PMU 6422,
which provides
power for the big
core and GPU
Phone ROM
UFS2.1
Battery holder
Charging
management
chip
Backlight drive
chip
LCD display
drive chip
TP/LCD module
connector
DC charging
switch
Flash drive chip
RGB sensor
Rear camera
connector
Huawei Confidential
Symptom
Various faults may occur. For
example, various power supply faults,
or the phone cannot be powered on.
VDD_PERI_0V75 has a power supply
fault, the phone cannot be powered on,
the system freezes, or the phone has
electricity leakage.
The phone cannot be powered on.
The phone cannot be powered on.
The phone cannot be powered on, the
system freezes or restarts, or the phone
has electricity leakage.
The phone cannot be powered on. The
main symptom is that the phone access
Com1.0 automatically after powered
on.
The phone cannot be powered on or
charged.
The phone cannot be charged, the
phone has electricity leakage, or the
phone cannot be powered.
There is not backlight, and the phone
has a black screen.
There is backlight, but without display.
The phone has a black, white, or erratic
screen.
There is a fingerprint sensor,
touchscreen, or display failure.
The phone cannot start SuperCharge.
The flash cannot be turned on.
There are issues, such as temperature
sensor failure and image color cast.
The rear camera malfunctions.
INTERNAL
Remarks
The phone screen
is normal, but the
phone appears to
have a black
screen due to lack
of backlight.
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