Huawei P20 - Table of Contents

EML-L29V100R001 Advanced Maintenance Manual V2.1
INTERNAL
2019-6-25
Huawei Confidential
Page 3 of 67
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