Huawei U8185 User manual

U8185
Maintenance Manual
Issue
1.0
Date
2012-03-23
HUAWEI TECHNOLOGIES CO., LTD.

Issue 1.0 (2012-03-23)
Huawei Proprietary and Confidential
Copyright © Huawei Technologies Co., Ltd.
i
Copyright ©Huawei TechnologiesCo., Ltd.2012. All rightsreserved.
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:
[e-mail]

U8185
Maintenance Manual
About This Document
Issue 1.0 (2012-03-23)
Huawei Proprietary and Confidential
Copyright © Huawei Technologies Co., Ltd.
ii
About This Document
Purpose
Prepared by
R&D
Date
2012-03-20
Reviewed by
Maintenance support team
Date
2012-03-23
Approved by
Service representative
Date
2012-03-23
Change History
Date
Version
Change Reason
Section
Description
Author
2012-03-20
V1.0
Released the
first issue.
R&D

U8185
Maintenance Manual
Contents
Issue 1.0 (2012-03-23)
Huawei Proprietary and Confidential
Copyright © Huawei Technologies Co., Ltd.
iii
Contents
About This Document.................................................................................................................... ii
1Product Introduction...................................................................................................................... 1
1.1Appearance..........................................................................................................................................................................1
1.2 Specifications .....................................................................................................................................................................1
2Applicable Scope and Precautions................................................................................................. 4
2.1Applicable Scope ...............................................................................................................................................................4
2.2 Precautions..........................................................................................................................................................................4
2.3 How to Obtain Product and Repair Information ..........................................................................................................4
3Exploded View................................................................................................................................. 5
4Components on the PCBA.............................................................................................................. 7
5Software Upgrade ......................................................................................................................... 10
5.1 Upgrade Preparation........................................................................................................................................................10
5.2 Upgrade Procedure ..........................................................................................................................................................10
5.3 Troubleshooting................................................................................................................................................................11
6Maintenance Tools ........................................................................................................................ 12
7Disassembly Procedure................................................................................................................. 14
8Assembly Procedure...................................................................................................................... 16
9Principles and Failure Analysis ................................................................................................... 18
9.1 Block Diagram.................................................................................................................................................................18
9.2 Baseband Unit ..................................................................................................................................................................19
9.2.1 Power-on Management Circuits..........................................................................................................................19
9.2.2 Charging Management Circuits ..........................................................................................................................24
9.2.3 Clock Circuit ..........................................................................................................................................................31
9.2.4 Memory Circuit......................................................................................................................................................32
9.3 RF Unit ..............................................................................................................................................................................34
9.3.1 GSM Quad Band Transception Circuit..............................................................................................................36
9.3.2 WCDMA2100/1900 Transception Circuit ........................................................................................................39
9.3.3 W900/850 Transception Circuit ..........................................................................................................................43
9.4 Peripheral Circuits ...........................................................................................................................................................48

U8185
Maintenance Manual
Contents
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9.4.1 Display ....................................................................................................................................................................48
9.4.2 Keypad.....................................................................................................................................................................50
9.4.3 Vibration..................................................................................................................................................................53
9.4.4 Voice Reception .....................................................................................................................................................54
9.4.5 Voice Transmission................................................................................................................................................58
9.4.6 Headset....................................................................................................................................................................60
9.4.7 SIM Card.................................................................................................................................................................63
9.4.8 I/O Connector.........................................................................................................................................................65
9.4.9 microSD Card Connector.....................................................................................................................................66
9.4.10 FM..........................................................................................................................................................................67
9.4.11 Bluetooth...............................................................................................................................................................70
9.4.12 Wi-Fi......................................................................................................................................................................73
10 Solder Points on the PCB and BGA Chip................................................................................. 75
11 Functional Tests........................................................................................................................... 81
11.1 Keys .................................................................................................................................................................................81
11.2 MMI Test.........................................................................................................................................................................82
11.3 Voice Call Test................................................................................................................................................................83

U8185
Maintenance Manual
1 Product Introduction
Issue 1.0 (2012-03-23)
Huawei Proprietary and Confidential
Copyright © Huawei Technologies Co., Ltd.
1
1 Product Introduction
1.1 Appearance
Figure 1-1 U8185
1.2 Specifications
Category
Description
Dimensions (H x W x D)
106.5 mm x 56 mm x 10.9 mm
Technical standard
WCDMA/GSM

U8185
Maintenance Manual
1 Product Introduction
Issue 1.0 (2012-03-23)
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2
Category
Description
Frequency bands
U8185-1:
WCDMA 900MHz: 880–915 MHz (UL), 925–960 MHz (DL)
WCDMA2100 MHz:1920–1980 MHz (UL), 2110–2170 MHz (DL)
GSM 850 MHz: 824–849 MHz (UL), 869–894 MHz (DL)
GSM 900 MHz: 880–915 MHz (UL), 925–960 MHz (DL)
GSM 1800 MHz: 1710–1785 MHz (UL), 1805–1880 MHz (DL)
GSM 1900 MHz: 1850–1910 MHz (UL), 1930–1990 MHz (DL)
U8185-5:
WCDMA 850MHz: 824–849 MHz (UL), 869–894 MHz (DL)
WCDMA 1900MHz: 1850–1910 MHz (UL), 1930–1990 MHz (DL)
GSM 850 MHz: 824–849 MHz (UL), 869–894 MHz (DL)
GSM 900 MHz: 880–915 MHz (UL), 925–960 MHz (DL)
GSM 1800 MHz: 1710–1785 MHz (UL), 1805–1880 MHz (DL)
GSM 1900 MHz: 1850–1910 MHz (UL), 1930–1990 MHz (DL)
U8185-7:
WCDMA 850MHz: 824–849 MHz (UL), 869–894 MHz (DL)
WCDMA2100 MHz:1920–1980 MHz (UL), 2110–2170 MHz (DL)
GSM 850 MHz: 824–849 MHz (UL), 869–894 MHz (DL)
GSM 900 MHz: 880–915 MHz (UL), 925–960 MHz (DL)
GSM 1800 MHz: 1710–1785 MHz (UL), 1805–1880 MHz (DL)
GSM 1900 MHz: 1850–1910 MHz (UL), 1930–1990 MHz (DL)
Weight
About 100 g with battery
Form factor
Bar
Antenna
Built-in
UIM
Support for the USIM card
Charger
5 V, 500 mA
5 V, 400 mA
Battery
1050 mAH
Li-ion
Talk time: up to 200 minutes
Standby time: up to 280 hours
Display
Resolution
240 RGB x 320 pixel
Type
TFT-LCD
Color
262 k
Size
2.83 inches
Connectors
Charging port
Micro USB connector
USB port
Micro USB connector

U8185
Maintenance Manual
1 Product Introduction
Issue 1.0 (2012-03-23)
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3
Category
Description
microSD card
slot
microSD card slot
Headset jack
3.5 mm headset jack
Maximum
transmit power
WCDMA: +24 dBm (Power Class 3)
GSM/GPRS 850/900 MHz: +33 dbm (Power Class 4)
GSM/GPRS 1800/1900 MHz: +30 dbm (Power Class 1)
Static sensitivity
WCDMA 850 MHz: better than –104.7 dBm/3.84 MHz
WCDMA 900 MHz: better than –103.7 dBm/3.84 MHz
WCDMA 1900 MHz: better than –104.7 dBm/3.84 MHz
WCDMA 2100 MHz: better than –106.7 dBm/3.84 MHz
GSM 850/900/1800/1900 MHz: better than –102 dBm/200 kHz
Temperature
Operating temperature: –10°C to +55°C
Storage temperature: –40°C to +70°C
Humidity
Operating humidity: 5% to 95% RH

U8185
Maintenance Manual
2Applicable Scope and Precautions
Issue 1.0 (2012-03-23)
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2 Applicable Scope and Precautions
2.1 Applicable Scope
This document provides repair instructions for technicians at service centers authorized by
Huawei. This maintenance manual is confidential and accessible to authorized service centers
(ASCs) and authorized service providers (ASPs) only. While every effort has been made to
ensure the accuracy of this document, errors may still exist. If you find any errors or have any
suggestions, please contact Huawei's customer service.
2.2 Precautions
Only qualified technicians are allowed to perform repair and calibration.
Perform all operations in electrostatic discharge (ESD) rooms and wear ESD wrist straps
throughout the operations.
Ensure that all the components, screws, and insulators are properly installed after repair
and calibration. Ensure that all cables and wires are installed and connected correctly.
Ensure that the soldering is lead-free and compliant with eco-friendly requirements.
2.3 How to Obtain Product and Repair Information
To obtain product and maintenance information, visit Huawei website at:
http://www.huaweidevice.com/cn/technicaIndex.do
ESD is the main cause of damage to electrostatic-sensitive components. Each
ASC must exercise caution to avoid ESD damage and comply with the ESD
protection requirements in this manual.

U8185
Maintenance Manual
3 Exploded View
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3 Exploded View
Note: The components listed in the following table are structural parts of the phone, and
cannot be used as reference when requesting spare parts.
Table 3-1 List of components in the exploded view drawing
No.
Description
Quantity
1
Touch panel (TP)
1
2
Front cover assembly
1
3
LCM
1
4
Printed circuit board assembly (PCBA)
1
5
Rear cover assembly
1