Huawei P20 lite User manual

EML-L29V100R001 Advanced Maintenance
Manual V2.0
Prepared By:
Gao Haizhen (employee ID: 00371199)
Date:
2018-01-19
Reviewed By:
Maintenance support
Date:
Approved By:
Service representatives
Date:
Huawei Technologies Co., Ltd.
All rights reserved

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Change History
Date
Version
Change Reason
Section No.
Change
Description
Author
2018-01-19
V1.0
Released the first
version.
Gao Haizhen (employee
ID: 00371199)
2018-02-27
V2.0
Updated RF-related
contents.
Chapter 4
Gao Haizhen (employee
ID: 00371199)
2018-02-27
V2.1
Updated flow chart
Chapter 4
Gao Haizhen (employee
ID: 00371199)

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Contents
1 Product Introduction and Specifications..................................................................................6
1.1 Product Introduction.........................................................................................................................................6
1.2 Product Specifications......................................................................................................................................6
2 Working Principles and Materials .............................................................................................8
2.1 Block Diagram.................................................................................................................................................8
2.2 Module Functions.............................................................................................................................................8
2.3 PCBA Components and BOM Information.................................................................................................... 11
2.4 Faulty Component Description ......................................................................................................................12
3 Software Maintenance Guide...................................................................................................15
3.1 Root Detection Instructions............................................................................................................................15
3.1.1 Forcibly Entering Fastboot Mode .........................................................................................................15
3.1.2 Entering Forcible Loading Mode (Forcible Update Mode) ..................................................................15
3.1.3 Detection in Fastboot Mode..................................................................................................................15
3.1.4 ADB Mode Detection (Only for Phones that Can Properly Start) ........................................................16
3.2 Software Update Guide..................................................................................................................................17
3.2.1 Updating a Rooted Phone .....................................................................................................................17
3.2.2 Updating an Unrooted Phone................................................................................................................19
3.3 Software Log Tool..........................................................................................................................................20
3.3.1 Log Tool................................................................................................................................................20
3.3.2 Instructions for Using the Log Tool......................................................................................................20
4 Troubleshooting ..........................................................................................................................22
4.1 Charging Failure.............................................................................................................................................22
4.1.1 Maintenance Process.............................................................................................................................22
4.1.2 Maintenance Principle...........................................................................................................................23
4.2 SIM Card Detection Failure...........................................................................................................................25
4.2.1 Maintenance Process.............................................................................................................................25
4.2.2 Maintenance Reference Networks ........................................................................................................26
4.3 LCD Failure ...................................................................................................................................................27
4.3.1 Maintenance Process.............................................................................................................................27
4.3.2 Maintenance Principle...........................................................................................................................28
4.4 Touchscreen Failure .......................................................................................................................................29
4.4.1 Maintenance Process.............................................................................................................................29
4.4.2 Maintenance Principle...........................................................................................................................30
4.5 Proximity/Ambient Light Sensor Failure.......................................................................................................31
4.5.1 Maintenance Process.............................................................................................................................31
4.5.2 Maintenance Principle...........................................................................................................................32
4.6 Accelerometer Failure ....................................................................................................................................33

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4.6.1 Maintenance Process.............................................................................................................................33
4.6.2 Maintenance Principle...........................................................................................................................34
4.7 Compass Failure.............................................................................................................................................35
4.7.1 Maintenance Process.............................................................................................................................35
4.7.2 Maintenance Principle...........................................................................................................................36
4.8 Hall Sensor Failure.........................................................................................................................................37
4.8.1 Maintenance Process.............................................................................................................................37
4.8.2 Maintenance Principle...........................................................................................................................37
4.9 Motor Failure .................................................................................................................................................38
4.9.1 Maintenance Process.............................................................................................................................38
4.9.2 Maintenance Principle...........................................................................................................................39
4.10 Receiver Failure ...........................................................................................................................................40
4.10.1 Maintenance Process...........................................................................................................................40
4.10.2 Maintenance Principle.........................................................................................................................41
4.11 Speaker Failure.............................................................................................................................................42
4.11.1 aintenance Process ..............................................................................................................................42
4.11.2 Maintenance Principle.........................................................................................................................42
4.12 Microphone Failure......................................................................................................................................43
4.12.1 Maintenance Process...........................................................................................................................43
4.12.2 Maintenance Principle.........................................................................................................................44
4.13 Headset Failure.............................................................................................................................................45
4.13.1 Maintenance Process...........................................................................................................................45
4.13.2 Maintenance Principle.........................................................................................................................46
4.14 Wi-Fi and Bluetooth Failure.........................................................................................................................47
4.14.1 Maintenance Process...........................................................................................................................47
4.14.2 Maintenance Principle.........................................................................................................................47
4.15 GPS Failure..................................................................................................................................................49
4.15.1 Maintenance Process...........................................................................................................................49
4.15.2 Maintenance Principle.........................................................................................................................50
4.16 RF Failure (CDMA).....................................................................................................................................51
4.16.1 Maintenance Process (Transmission)..................................................................................................51
4.16.2 Maintenance Principle (Transmission)................................................................................................52
4.16.3 Maintenance Process (Reception).......................................................................................................53
4.16.4 Maintenance Principle (Reception).....................................................................................................54
4.17 RF Failure (WCDMA) .................................................................................................................................55
4.17.1 Maintenance Process (Transmission)..................................................................................................55
4.17.2 Maintenance Principle (Transmission)................................................................................................56
4.17.3 Maintenance Process (Reception).......................................................................................................57
4.17.4 Maintenance Principle (Reception).....................................................................................................58
4.18 RF Failure (GSM) ........................................................................................................................................59
4.18.1 Maintenance Process (Transmission)..................................................................................................59
4.18.2 Maintenance Principle (Transmission)................................................................................................60

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4.18.3 Maintenance Process (Reception).......................................................................................................60
4.19 RF Failure (TDS/LTE) .................................................................................................................................61
4.19.1 Maintenance Process (Transmission)..................................................................................................61
4.19.2 Maintenance Principle (Transmission)................................................................................................62
4.19.3 Maintenance Process (Reception).......................................................................................................64
4.19.4 Maintenance Principle (Reception).....................................................................................................65

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1 Product Introduction and Specifications
1.1 Product Introduction
The EML is a Huawei-developed, dual card (L+G/W) dual standby single active smartphone that supports
voice services. It has the following features:
EMUI 8.0 (compatible withAndroid 8.0)
HUAWEI Kirin 970, 4x Cortex-A73 2.4 GHz+4x Cortex-A53 1.8 GHz
5.824 inches, 1080RGBW x 2244, 16.7 M colors, 10-point touch
3400 mAh (typical) battery capacity
Rear camera: 12 MP+20 MP, AF, f/1.6+f/1.8 aperture, laser focusing, single-tone flash
Front camera: 24 MP, FF, f/2.0 aperture
1.2 Product Specifications
Operating system: Huawei EMUI 8.0 (compatible with Android 8.0)
UI: Huawei EMUI 8.0
CPU: Kirin 970
CPU core: octa-core
CPU dominant frequency: 4x CortexA73 2.36GHz+4x CortexA53 1.8GHz
GPU: Mali-G72 MP12
Dual card dual standby single active, either card slot can be set to accommodate the primary SIM card,
nano-SIM
Browser: Huawei EMUI 8.0 browser
Screen size: 5.824 inches
Screen color: 16.7 M colors; color saturation (NTSC): 96% (typical)
Screen: negative LCD TFT screen, contrast of 1500:1 (typical)
Resolution: 2244 x 1080 pixels
Touchscreen: multi-touch sensitive screen
Gravity sensor: supported
Light sensor: supported
Proximity sensor: supported
Fingerprint sensor: supported
Hall sensor: supported

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Barometer: supported
Gyroscope: supported
Compass: supported
Mode supported by NFC: card reader mode, point-to-point mode, card simulation mode (Wallet payment,
*SIM card payment, and HCE payment); *SIM cards for SIM card payment can only be in slot SIM1.
RAM: 4 GB/6 GB
ROM: 128 GB/64 GB
Audio effect: Huawei Histen
Rear camera: 20 MP (monochrome)+12 MP (RGB), f/1.6 aperture, Leica lens
Front camera: 24 MP, f/2.0 aperture, Leica lens
Sensor type: BSI CMOS
Flash: single-tone flash
Wi-Fi 802.11a/b/g/n/ac; with support for 2.4G and 5G and direct WI-FI connection
DLNA: not supported
Wi-Fi hotspot: supported
Bluetooth: Bluetooth 4.2, with support for BLE, with support for high-definition audio of aptX, aptX HD,
and LDAC
USB: USB 2.0, with support for USB network tethering, USB charging, OTG function, and DP function
Positioning: GPS/GLONASS/BeiDou
Battery: Li-Polymer battery
Battery capacity: 3400 mAh (typical)
Charging time: about 90 minutes
Data cable port: Type-C USB port
Headset jack: Type-C headset jack
SIM card type: nano-SIM card; both card slots support nano-SIM cards.
Phone size: 150.5 mm x 77.8 mm x 8.2 mm (L x W x D)
Weight: approximately 156 g (including the battery)

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2 Working Principles and Materials
2.1 Block Diagram
Figure 2-1 Phone system block diagram
Fingerprint
sensor
Gravity sensor, ambient
light sensor, compass, hall
sensor, and gyroscope
Front camera
Rear
camera+flash
4lane MIPI
SPI2
I2C
SPI3
CSI1
DDR
UFS
PCIE
UART4
I2S
Mic x 2
I2S
SIM1
SIM0
SIM SIMSSI CLK CLK
SSI
38.4 MHz
32 kHz
RGB LED
Bluetooth
/Wi-Fi
SSI
IQ
38.4 MHz
Type-C USB
USB 3.0
USB OTG VBUS
BQ25892
charger IC
(U1603)
U1201
Buckboost
(U1201)
HI6403
Codec
(U2201)
Smart PA
(U2501)
HI6421
PMU
(U1000)
HI6363
transceiver
X 2
(U3301&U4501)
RF: FEM
Wi-Fi
Bluetooth
HI3670 SOC
(U300)
For displaying
charging status
and notification
4Lane Dual
MIPI
CSI0&2
 TP/LCD
DSI0
38.4 MHz Vibrator
HI6422
PMU
(U1301)
38.4
MHz
DCDC
DCDC+LDO
LPDDR4X
U300_POP
DCDC BCM43596
(U5100)
Hi6423
U1101
UFS2.1
U1400
GPS
BCM477 4
U5603
GPS
UART3
Direct
charging
load switch
U1801
VBAT
SuperSwitch
USB 2.0
VBUS_CONUSB OTG
VBAT_SYS
The entire system is composed of the board, built-in battery, and mechanical parts. The board incorporates
the printed circuit board assembly (PCBA), side button FPC, main FPC, proximity sensor sub-board,
antenna sub-board, and other components such as the LCD module, camera module, motor, microphone,
speaker, and receiver. Mechanical parts include the middle cover, rear cover, main antenna,
GPS/Wi-Fi/Bluetooth antenna, and GSM antenna for the secondary SIM card.
2.2 Module Functions
Based on the logical functions, the board can be divided into four subsystems: baseband, RF, power supply,
and user ports. The following table describes the modules and units subordinated to each subsystem and
their functions.
Subsystem
Module
Unit
Function
Baseband
HI3670
Application unit
Octa-core processor, with support for function
modules, such as SD 3.0, UART, SPI, SDIO,
I2C, I2S, PCM, HSI, HSIC, MIPI, DVP, GPIO,
HDMI, USB, keypad, LPDDR4 controller,

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Subsystem
Module
Unit
Function
UFS, and PWM
User port processing
unit
Manages ports of the camera, PCM, I2S, RF,
LCD, USB, UART, MIPI, GPIO, JTAG, SPI,
and keypad
Multimedia and
game engine
Provides the MPEG/JPEG hardware engine,
game engine, JAVA accelerator, and
MP3/MMS/MIDI functions.
Modem unit
Supports HSPA+, LTE-FDD, LTE-TDD,
TDS-HSPA, and dual card dual standby dual
active.
HI6421
PMU
The chip supplies power to the Hi6421 and
multiple peripheral components, including 8
buck power supplies, 29 LDOs, 1 boost, 4
LVSs, 16 HKADCs, 2 AUXDACs, the reset
circuit, the motor drive, the LED drive, the
built-in flash drive, the class-D audio PA, and
the built-in Coulombmeter.
RF
Transmission
and reception
of WCDMA
and GSM
signals
Performs the RF function of WCDMA signal
reception and transmission. This module
includes the RF chip, PMU, and peripheral
circuits.
GPS
GPS reception
module
Receives and processes GPS signals, mainly
including the BCM4752 chip and peripheral
circuits.
Bluetooth port
Bluetooth module
Performs the Bluetooth baseband function, and
transmits and receives RF signals. This unit
includes the BCM4334 and peripheral circuits.
Wi-Fi port
Wi-Fi module
Performs the Wi-Fi baseband and RF
transmission and reception functions. This unit
includes the Wi-Fi part of the BCM4359 chip
and peripheral circuits.
Antenna
External antenna,
internal port
components, and
antenna protection
The phone uses built-in antennas for wireless
communication, supporting WCDMA high and
low frequency bands. The EDGE+ phone
antennas include the primary antenna,
Wi-Fi/Bluetooth/GPS antenna, and GSM
antenna for the secondary card.
User port
UART port
UART4 applies to the Bluetooth, Wi-Fi, and
FM chips, while UART3 applies to the GPS
chip.
USB port
Drive, protective
circuits, and output
port components
Refers to the USB port peripheral circuit,
protective circuit, and port connector in the
SOC and MHL subsystems. The USB port is a
main data service channel for an engineering

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Subsystem
Module
Unit
Function
prototype and is also used for device
commissioning and testing during the R&D
process.
SIM card ports
Power supply,
protective circuit,
and SIM card tray
Includes the SIM card tray and related
connection circuits.
Color LCD and
backlight
LCD drive,
connection method,
and backlight
control
Both the phone screen and the LCD backlight
brightness are controlled using the CABC and
LABC functions.
Speaker
Drive method,
connection method,
and speaker
components
The power of the speaker that plays polyphonic
ringtones for incoming calls can be 500 mW.
This unit features good frequency responses to
play 20 Hz to 20 kHz audio files and can also
be used as a mono speaker to play MP3 files.
Receiver
Drive method,
connection method,
and receiver-related
components
The power of the receiver for calls must be less
than 30 mW.
Microphone
Port circuit,
connection method,
and
microphone-related
components
The phone features dual built-in silicon
microphones with noise reduction.
Earphone
Headset, headset
jack circuit, and
microphone port
circuit
The phone provides a headset jack for call
output or MP3 output. The microphone is
located on the headset line to transmit the
sound to the phone.
Vibrator port
Drive method,
connection method,
and vibrator
This unit vibrates when a call is received.
Accelerometer
I2C port control
The accelerometer is an auxiliary module of the
game engine.
Gyroscope
I2C port control
3-axis angular rate sensor
Compass
I2C port control
Geomagnetic sensor
Fingerprint
sensor
SPI port control
Identifies fingerprints.
Proximity
sensor
I2C port control
Senses ambient light and proximity light.
Hall sensor
GPIO control
Senses protective cases.
Power
distribution
network and
Power distribution
network
This unit includes filtering networks and cables
for the power supply.
Backup battery
PMIC charges the capacitor for maintaining the

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Subsystem
Module
Unit
Function
power
management
function
management
RTC current.
Power management
of board circuits
(power-on and
power-off analysis)
Mainly refers to the LDO, which manages the
power supply flexibly. The board software
manages power supplies to circuits on the
board based on service status, protocols, or
power-saving analysis to reduce power
consumption. Three channels of 32 kHz clocks
are provided.
Charging IC
Supports dynamic path management, charges
the battery while providing power, and
prioritizes power supply.
RF PMIC
Provides the RF core voltage.
2.3 PCBA Components and BOM Information
The following is the PCBAcomponent document.
PC B A
C o m p o nents inEM L-L29V 100R 001A d vanced M aintenance M anual_V 2.0-20180227.xlsx

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2.4 Faulty Component Description
The following table describes component faults.
C o m p o nent
M aintenance G uid e inEM L-L29V 100R 001A d vanced M aintenance M anual_V 2.0-20180227-原稿.xlsx
No.
Designator
Description
Symptom
Remarks
1
U300
SOC
U300 is the system's main control chip.
If it fails, the symptoms may vary. For
example, the phone cannot be powered
on, the system freezes, the phone
restarts repeatedly, or the phone has
various malfunctions. Replace U300
only if you are sure SOC is faulty.
Replace SOC only
when other
methods do not
work.
2
U300_POP
DDR
Various stability faults may occur. For
example, the phone cannot be powered
on, restarts repeatedly, or freezes.
DDR and SOC are
bound together.
Only if you are
sure that DDR is
defective, replace
DDR.

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

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No.
Designator
Description
Symptom
Remarks
18
J2002
Front camera
connector
The front camera malfunctions.
19
U2101
Super switch
There are charging failures and power
leakage that lead to power-on failures.
There is no port, and the OTG and DP
headset cannot be detected.
Because there are
too many
integrated
functions, the
interface charging
failures are
coupled easily.
Check other
components
related to the
faulty function
first.
20
U2102
DP two-way
transfer switch
The DP cannot be detected, or only one
side can be detected. The analog
headset cannot be detected.
21
U2201
Audio Codec
chip
Various audio faults may occur.
22
U2301
Motor drive chip
There are failures. For example, the
motor does not vibrate or vibrates
continuously or abnormally.
23
MIC2301
Secondary
microphone
The microphone fails, especially in the
hands-free mode.
24
U2501
Speaker smart
PA
Faults, such as noise or no sound from
the speaker, occur.
25
U2505
BST5V power
supply chip
There is an NFC failure, or
SuperCharge cannot be detected.
26
U2601/U2604
Compass
The compass does not work properly.
27
U2602
Accelerometer
and gyroscope
sensor
Functions, such as step counting,
knuckle screenshot, and auto screen
rotating, are abnormal.
28
U2603
Laser
range-finding
sensor
The rear camera focuses slowly.
29
LED2601
Tricolor LED
The indicator does not work.
30
U2701
Infrared control
analog switch
The infrared function fails.
31
J2802
Dual SIM card
tray
SIM cards cannot be detected.
MicroSD cards are
not supported.
32
J2901
Main FPC
connector
The phone cannot be charged, the
speaker fails, the motor fails, the
microphone fails, smart cover mode,
Check the
connection of
fastened points or

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No.
Designator
Description
Symptom
Remarks
DP display, or port detection fails, or
other failures related to sub-board
functions occur.
adhered substance
first.
33
J2902
Proximity
sensor/Ambient
light sensor
The proximity sensor/ambient light
sensor malfunctions.
34
J2903
RGB tri-color
LED connector
The LED malfunctions.
35
J2904
Side button FPC
connector
The power button and volume buttons
do not work.
3 Software Maintenance Guide
3.1 Root Detection Instructions
3.1.1 Forcibly Entering Fastboot Mode
1. Connect the phone to a computer using a USB cable. Power on the phone, press and hold the power
and volume down buttons for 10s, and wait for the phone to power off.
Expected symptom: The black screen is displayed.
2. Keep pressing and holding the power and volume down buttons, and then release the buttons when the
phone enters the fastboot screen.
Expected symptom: The fastboot page is displayed. The fastboot port is displayed in the Device Manager
on the computer.
3.1.2 Entering Forcible Loading Mode (Forcible Update Mode)
1. When the phone is powered on, press and hold the power button for 10s until the phone is powered
off.
Expected symptom: The black screen is displayed.
2. Once the phone is powered off, press the power, volume up, and volume down buttons. Connect the
phone to a computer using a USB cable.
Expected symptom: The USB update screen is displayed. The ADB port and PCUI port are displayed in the
Device Manager on the computer.
3.1.3 Detection in Fastboot Mode
1. Follow the instructions in section 3.1.1 "Forcibly Entering Fastboot Mode" to enable the phone to
enter the fastboot mode. Then, connect the phone to a computer using a USB cable.
2. Run the NFF detection tool compartner.exe. The automatic detection starts. If the detection result is
locked, the phone has not been rooted. If the detection result is unlocked, the phone has been rooted.

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3.1.4 ADB Mode Detection (Only for Phones that Can Properly Start)
Connect the phone to the computer using the USB cable. Run the NFF detection tool compartner.exe. The
automatic detection starts. The phone carries out the MMI test (you can skip this test by
following the on-screen instructions) before the root test. The method for displaying test
results is the same as that for displaying test results in fastboot mode.

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3.2 Software Update Guide
3.2.1 Updating a Rooted Phone
After a phone is rooted, use the fastboot tool to erase all data. Then, update the board software again.
Step 1. Run the Fastboot Erase Tool. Click the button marked as 1 next to Configure file, and enter the
password huawei. Select the required .xml file from the MHA factory-level software package.

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Step 2. Check the interface switch configuration. Click ADB to Fastboot to switch to the fastboot
download mode. If the driver is installed properly, a message is displayed indicating the switch success, as
shown in the following figures. After the phone switches to the fastboot mode, the screen freezes at
HUAWEI ASCEND.
Step 3. Click Totally Erase to start erasing all data from the flash memory. After the total erase, the phone
IMEI and RFNV are lost, and the phone cannot be powered on or directly updated. The phone can be
powered on after you load the factory-level software using the IDT tool.
Step 4. After the flash memory is totally erased, the phone displays a black screen and cannot be powered
on. The port is displayed below. Download the USB driver for the production line, and select VCOM to
update the phone. After the driver is updated, the HUAWEI USB COM 1.0 port is displayed in
the Device Manager on the computer.

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----End
3.2.2 Updating an Unrooted Phone
Before the update, make sure that the phone has not been rooted.
1. Use the USB cable to update the phone when the phone can be properly powered on.
2. When the phone cannot be properly powered on, update it using either of the following methods:
(1) The phone can enter the forcible loading mode (For details, see section 3.1.2): Use the USB
cable to update the phone in forcible loading mode. The following table describes the
update procedure.
Update Using the USB Cable
1. Press and hold the power button for 10s until the phone is powered off.

EML-L29V100R001 Advanced Maintenance Manual V2.1
INTERNAL
2019-6-25
Huawei Confidential
Page 20 of 67
2. Press the power button and volume up and down buttons simultaneously. Connect the phone to the
computer using the USB cable. The phone then enters forcible loading mode. The PCUI port can be
identified.
3. Download the official UPDATE.APP file and USB update tool.
4. Use the NewMultiDownloadU_1.exe tool to update the UPDATE.APP file.
(2) The phone cannot enter forcible loading mode: Enable the phone to enter fastboot mode (For
details, see section 3.1.1). Update the phone in fastboot mode. (This method is usually used by
software developers to update versions.) Wait for the phone to properly start. Update the phone
using the USB cable. If the phone cannot be powered on, update it in fastboot mode, as shown in
the following table.
Update in Fastboot Mode
1. Press and hold the power button for 10s until the phone is powered off.
2. Press and hold the power and volume down buttons simultaneously. Connect the phone to the
computer using the USB cable to forcibly enable the phone to enter fastboot mode. The fastboot port is
displayed in the Device Manager on the computer.
3. Download the official .img file. Use the fastboot burn script to burn the .img file. The burn script
updateinadb-sec.bat is attached below.
This method is used to enable the system to temporarily start so that the phone can be updated using the
USB cable. In general, you only need to burn the partition files that affect system startup during fastboot
burning. In most cases, the phone can properly start once you burn the Sec_boot.img, system.img, and
userdata.img files. The burn script updateinadb-sec.bat is attached below.
3.3 Software Log Tool
3.3.1 Log Tool
NOTE
The log tool is used by software developers to capture logs, which help them locate phone hardware and software
problems.
3.3.2 Instructions for Using the Log Tool
1. On the dialer screen, enter *#*#2846579#*#* to enter the engineering mode. Choose Project Menu >
Background Settings > DumpLog. Enable the log switch by selecting the related option. Use the log
tool to capture logs and send them to software developers.