Huawei U8850 Schematics
U8850-91 L3-L4 Trouble shooting Guide
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L3-L4 Troubleshooting Guide
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U8850-91 L3-L4 Trouble shooting Guide
Date
Version
Comment
Owner
2011-07-21
0.1
First release
Paul Lin
Max Kao
Revision History
Version 0.1
Content
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U8850-91 L3-L4 Trouble shooting Guide
Version 0.1
1 BASEBAND TROUBLE SHOOTING GUIDE….……………..………..…...6
1.1 U8850-91 Baseband: General Description of U8850-91 BB Circuits…..6
1.1.1 U8850-91 system structure introduction…………….……………….….6
1.2 Base-band Test-points…………………….…………………………..….…8
1.3 Can not power on the Phone……………………………………………..10
1.3.1 Causes of “Cannot power on the phone ”……………………………..10
1.3.2 Flow chart for “Cannot power on Phone”……….……….......………..11
1.4 Download Failed….......……………………………………………………..12
1.4.1 Causes of “Download Failed”…………………………………………..12
1.5 SIM Card Detection Error…………………….…………………………….14
1.6 Audio……………………………………………………………………….…15
1.6.1 Headset fail…………….……………………………………….………...15
1.6.2 Speaker fail………………………………………………………………..17
1.6.3 Receiver fail………………………………..………………………..……18
1.6.4 Microphone fail……………….………………………………………….19
1.7 LCD Fault…………………………………………………………………..20
1.7.1 Backlight fail…………….……………………………….…………………20
1.7.2 LCM no display……………….……………………………………………21
1.8 Charger Fault…………………………………………………………………23
1.9 Micro SD Card fault ..……………………………………………………..…24
1.10 Bluetooth / WIFI fault……………………………………………………….25
1.11 Camera fault……………………………………………………………..….28
1.11.1 5M Camera fault…………………………………………………….……28
1.11.2 VGA Camera fault…………………….……………………………….…30
1.12 Vibrator fault…………………………………………………………...……32
2 RF TROUBLE SHOOTING GUIDE ………………………………………… 33
2.1 WCDMA Troubleshooting ……………………………………….………… 33
2.1.1 Operation Channel and Frequency Allocation …………………...…… 33
2.1.2 RF block diagram ……………………………………………………..… 34
2.1.3 WCDMA components/layout …………………………………………… 35
2.1.4 WCDMA test setup ………………………………………………….…… 37
2.1.5 How to set 8960 cable loss ………………………………...…………… 42
2.2 WCDMA Troubleshooting ………………………………………….……… 44
2.3 GSM Troubleshooting ……………………………………………...……… 46
2.3.1 GSM Block …………………………………………………………..…… 46
2.3.2 GSM component locations ……………………………………………… 47
2.3.3 Agilent 8960 setting ……………………………………………………… 49
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2.3.4 GSM Circuit Checking Steps …………………………………………… 60
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1 BASEBAND TROUBLE SHOOTING GUIDE
1.1 U8850-91 Baseband: General Description of U8850-91 BB Circuits
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1.1.1 U8850-91 system structure introduction
The Base-band circuits mainly consist of 3 chips: QUALCOMM
MSM8255-1, PM8058, QTR8601, SanDisk eMMC memory (SDIN5D2-2G-T)
and Samsung mobile DDR (K4X4G303PC-7GD8) .
QUALCOMM MSM8255-1 (U401) is a chip implementing the digital
Base-band processes of a GSM/GPRS/WCDMA mobile phone and basic
PDA function. Qualcomm MSM8255-1 Smartphone Chipsets family will offer
800MHz to 1GHz CPUs based on the ARM11 instruction set. The CPU used
will be the same Scorpion models found in current Snapdragon chipsets.
Scorpion is 800MHz, Modem ARM11 is 400MHz.
The PM8058 (PU101) integrates all wireless handset power
management, general housekeeping, and user interface support functions
into a single, mixed-signal IC. Its versatile design is suitable for CDMA,
UMTS, or GSM phones, and other wireless products, such as data cards and
PDAs.
The QTR8601 (WQU801) device is a highly integrated and versatile
transceiver IC that can be used in multimode, multiband applications – with
or without Rx diversity. The RF transceiver block integrates advanced
receive and transmit features to simplify handset design, minimize parts
count, and reduce DC power consumption.
QTR8601 features
New features integrated into the QTR8x0x IC, RF transceivers, RF
transmitters, RF receivers, RF transceiver support features, Bluetooth
features, FM radio features, Audio codec features, Touchscreen ADC,
Package features
A specific module is dedicated to support the 1.8V/3V SIM card interface.
The module includes the generation of the SIM card supply voltage as well
as level shifters to adapt the SIM card signal levels to the micro-controller I/O
signal levels.
The PM8058 also includes an on-chip voltage reference; under-voltage
detection and power-on reset circuits.
The SanDisk eMMC memory (SDIN5D2-2G-T) (U1001) is used to store code
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and personal data.
The Samsung mobile DDR (K4X4G303PC-7GD8) is used for temporary data
stack for code running.
Block diagram of U8850-91 system structure
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Power source Net Name
Test Point
Voltage
VREG_S0_V1P2
PC104
1.2V
VREG_S1_V1P2
PC106
1.2V
VREG_S2_V1P3
PC101
1.3V
VREG_S3_V1P8
PC113
1.8V
VREG_S4_V2P2
PC118
2.2V
VREG_L1_V1P2
PC129
1.2V
VREG_L5_V2P85
PC131
2.85V
VREG_L8_V1P8
PC132
1.8V
VREG_L9_V2P05
PC133
2.05V
VREG_L10_V2P2
PC134
2.2V
VREG_L13_V2P9
PC135
2.9V
VREG_L14_V2P85
PC136
2.85V
VREG_LCM_VDD_V2P8
PC137
2.8V
VREG_L16_V1P8
PC138
1.8V
VREG_L22_V1P2
PC139
1.2V
VREG_L0_V1P2
PC141
1.2V
VREG_L3_V1P8
PC142
1.8V
VREG_L11_V1P8
PC143
1.8V
VREG_L12_V3
PC144
3.0V
VREG_L17_V1P8
PC145
1.8V
VREG_L18_V2P2
PC146
2.2V
VREG_L19_V1P8
PC147
1.8V
VREG_L20_V2P85
PC148
2.85V
VREG_L21_V1P1
PC149
1.1V
VREG_L24_V1P2
PC150
1.2V
VREG_L25_V1P2
PC151
1.2V
VREG_L6_V3P3
PC153
3.3V
VREG_L7_V1P8
PC154
1.8V
VREG_NCP_V1P8
PC155
1.8V
1.2 Base-band Test-points
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Clock
Net Name
Test Point
Value
WWU1102_OUT.1
37.4MHz
WWR1103
37.4MHz
XTAL_19.2M_OUT
19.2MHz
WQC821
19.2MHz
LPA_XTAL_OUT
24.576MHz
C502
24.576MHz
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1.3 Cannot power on the Phone
1.3.1 Causes of “Cannot power on the phone ”
„Phone is dead‟ means that the phone cannot be powered on when
the power has been supplied to the system. Nominal supply voltage to
the phone is 3.6V. If the main supply voltage is lower than 3.2V, the
phone does not start the power-on sequence. The causes of “Phone is
Dead” could be one of the following reasons:
Defective Mechanical Component: Battery connector
Defective PM8058: PU101
Defective QUALCOMM MSM8255-1: U401
Defective 32.768KHz crystal : X1201
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1.3.2 Flow chart for “Cannot power on Phone”
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1.4 Download Failed
1.4.1 Causes of “Download Failed”
The causes of Download failed could be one of the following reasons:
Defective CPU, DDR: U401(Qualcomm MSM8255-1), U1401
(Samsung K4X4G303PC-7GD8)
Defective Flash Memory: U1001 (SanDisk eMMC
SDIN5D2-2G-T)
Defective USB connector: CN1201
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Flow chart for “USB Download Failed”
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1.5 SIM Card Detection Error
The SIM interface can be checked tested without a SIM Card. When the phone
is switched on, all interface lines (VDDSIM, SIMRST, SIMCLK, SIMIO) rises,
first to 1.8V then 3V. From checking those responses, it is possible to find errors
in the SIM interface without a SIM Card.
Version 0.1
Test Points of “SIM Detection Error”
Flow chart for “SIM detection Failed”
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U8850-91 L3-L4 Trouble shooting Guide
(All Close to AU201)
Headset
AC216 470nF
AC212
33pF
AC217 470nF
AC218
33pF
AC219
33pF
AL203
BLM15AG121SN1
21
ATP203
ATP202
HPO_L [13]
HPO_R [13]
VREG_L20_V2P85
HP_VDD
HPH_LP[16]
HPI_L
PA_HEADSET_EN[6]
HPH_RN[16]
HPI_R
AC213
33pF_NM
AU201
NCP2811BFCT1G
AGND
A1
SD
A2
INR
B2
VP
B1
INL
B3
CPP
C1
CPM
C3
PGND
C2
PVM
C4
SPVM
B4
OUTL
A4
OUTR
A3
AC214
2.2uF
AC220
1uF
AC215 1uF
AR207 10/+-5%
AR206 10/+-5%
AR205 100K/+-5%
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1.6 Audio
Audio function block diagram
1.6.1 Headset fail
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Flow chart of “Headset receiver fail”
Flow Chart of “Headset microphone fail”
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AL102 BLM15AG121SN1
2 1
SPKIN-
Close to NCP2823
LINE_N
LINE_P SPKIN+
AL103 BLM15AG121SN1
2 1
VO1_N
EAC101
PESD5V0S1BL
1
1
2
2
AC109
22uF_NM
Close to NCP2823
AC107
4.7uF
AC108
4.7uF
V_BAT
EAC102
PESD5V0S1BL
1
1
2
2
Close to Connector
35pF
35pF
VO1_P
ATP101
SPK_EN [6]
AC110 5.6nF
AC111 5.6nF
AR101 68K/+-1%
ATP103
VO1- [13]
VO1+ [13]
AR102 68K/+-1%
Close to NCP2823
AU101
NCP2823AFCT2G
INP
A1
AVDD
B1
INN
C1
AGND
A2
PVDD
B2
EN
C2
VOUTN
A3
PGND
B3
VOUTP
C3
AC113
33pF
AC112
33pF
AC114
33pF
AC115
33pF
LINE_OUT_LP[16]
LINE_OUT_RN[16]
1.6.2 Speaker fail
Flow chart of “Speaker fail”
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1.6.3 Receiver fail
AC119
33pF_NM
AC118
33pF_NM
ATP104
ATP105
EAROP [13,16]
EARON [13,16]
AC116
33pF
AC117
33pF
EAROP[13,16]
EARON[13,16]
U8850-91 L3-L4 Trouble shooting Guide
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Flow chart of “Receiver fail”
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AC123
33pF
AC120 0.1uF
PM8058_1.8V
AC121 0.1uF
AC124
10uF
ACN101
501591-1011
1 2
4
5 6
7
9
3
8
10
11 12
13 14
AC122
33pF
MIC1P+
MIC1N-
APAD101
HSED_BIAS0
MIC1N[16]
MIC1P[16]
1.6.4 Microphone fail
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Flow chart of “Microphone fail”
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