Huawei U8815 User manual

U8815

Maintenance Manual

Issue

1.0

Date

2012-02-13

HUAWEI TECHNOLOGIES CO., LTD.

Issue 1.0 (2012-02-13)

Huawei Proprietary and Confidential

No part of this document may be reproduced or transmitted in any form or by any means without prior

written consent of Huawei Technologies Co., Ltd.

Trademarks and Permissions

and other Huawei trademarks are trademarks of Huawei Technologies Co., Ltd.

All other trademarks and trade names mentioned in this document are the property of their respective

holders.

Notice

The purchased products, services and features are stipulated by the contract made between Huawei and

the customer. All or part of the products, services and features described in this document may not be

within the purchase scope or the usage scope. Unless otherwise specified in the contract, all statements,

information, and recommendations in this document are provided "AS IS" without warranties, guarantees or

representations of any kind, either express or implied.

The information in this document is subject to change without notice. Every effort has been made in the

preparation of this document to ensure accuracy of the contents, but all statements, information, and

recommendations in this document do not constitute a warranty of any kind, express or implied.

Huawei Technologies Co., Ltd.

Address:

Huawei Industrial Base

Bantian, Longgang

Shenzhen 518129

People's Republic of China

Website:

http://www.huawei.com

Email:

[email protected]

U8815

Maintenance Manual

About This Document

Issue 1.0 (2012-02-13)

Huawei Proprietary and Confidential

About This Document

Purpose

Prepared by

R&D personnel

Date

2012-02-20

Reviewed by

Maintenance support team

Date

2012-02-23

Approved by

Service representative

Date

2012-02-23

Change History

Date

Version

Change Reason

Section

Description

Author

2012-02-23

V1.0

Released the first draft.

R&D personnel

U8815

Maintenance Manual

Contents

Issue 1.0 (2012-02-13)

Huawei Proprietary and Confidential

iii

Contents

1 Product Introduction ....................................................................................................................1

1.1 Appearance.......................................................................................................................................................1

1.2 Features............................................................................................................................................................1

2 Maintenance Instructions............................................................................................................3

2.1 Applicable Scope..............................................................................................................................................3

2.2 Precautions.......................................................................................................................................................3

2.3 Obtaining Product and Maintenance Information ............................................................................................3

3 Exploded View...............................................................................................................................4

4 PCBA Components .......................................................................................................................6

5 Software Upgrade .........................................................................................................................9

5.1 Upgrade Preparation.........................................................................................................................................9

5.2 Upgrade Process...............................................................................................................................................9

6 Maintenance Tools......................................................................................................................11

7 Disassembly Procedure..............................................................................................................13

8 Assembly Procedure...................................................................................................................17

9 Principles and Failure Analysis ...............................................................................................20

9.1 Block Diagram and Handset Introduction......................................................................................................20

9.2 Baseband Unit................................................................................................................................................21

9.2.1 Power-on Management Circuits............................................................................................................21

9.2.2 Charging Management Circuits ............................................................................................................26

9.2.3 Clock Circuit.........................................................................................................................................30

9.2.4 Flash Memory Circuit...........................................................................................................................32

9.3 RF Unit...........................................................................................................................................................37

9.3.2 Power Amplifier....................................................................................................................................38

9.3.3 Troubleshooting ....................................................................................................................................40

9.4 Peripheral Circuits..........................................................................................................................................44

9.4.1 Display Screen ......................................................................................................................................44

9.4.2 Vibration ...............................................................................................................................................48

9.4.3 Call Reception.......................................................................................................................................49

9.4.4 Call Transmission..................................................................................................................................53

U8815

Maintenance Manual

Contents

Issue 1.0 (2012-02-13)

Huawei Proprietary and Confidential

9.4.5 Headset..................................................................................................................................................57

9.4.6 SIM Card...............................................................................................................................................59

9.4.7 I/O Connector........................................................................................................................................60

9.4.8 microSD Card Connector......................................................................................................................61

9.4.9 FM.........................................................................................................................................................63

10 Solder Points on the PCB and BGA Chip.............................................................................66

11 Performance Test.......................................................................................................................69

11.1 Keys..............................................................................................................................................................69

11.2 MMI Test......................................................................................................................................................70

11.3 Voice Call Test..............................................................................................................................................71