FLY IQ4501 Service Manual

Service Manual

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CONTENT

1 OUTLINE ................................................................................................................................................. 3

1.1 MOBILE PHONE INTRODUCTION..................................................................................................... 3

1.2 MOTHERBOARD COMPONENTS DISTRIBUTION ........................................................................................... 6

2 SIGNAL FLOW AND FAULT ANALYSIS ...................................................................................................... 7

2.1 RF PART ............................................................................................................................................ 7

2.1.1 Block Diagram of the RF Section ............................................................................................. 7

2.1.2 Signal Flow OF the RF Transmitting Part.................................................................................. 7

2.1.2.1 Receiving and Transmit Path ............................................................................................ 7

2.1.2.2 Maintenance Procedures of the Transmitting Part .......................................................... 9

2.1.3 Signal Flow of the Receiving Part .......................................................................................... 10

2.1.3.1 Receiving Part Components ........................................................................................... 10

2.1.3.2 Maintenance Procedures of the Receiving Part ........................................................ 10

2.2 BASEBAND PART ................................................................................................................................ 12

2.2.1 Block Diagram of the Baseband Part ..................................................................................... 12

2.2.2 Power Management Part ...................................................................................................... 13

2.2.2.1 The Whole Power Supply System ................................................................................... 14

2.2.3 Audio Part .............................................................................................................................. 15

2.2.3.1 Audio CODEC Circuit ...................................................................................................... 15

2.2.3.2 MIC, RECEIVER LOOP ...................................................................................................... 16

2.2.3.3 HEADSET LOOP ............................................................................................................... 17

2.2.4 BASEBAND FAUIT ISSUES ....................................................................................................... 18

2.2.4.1 Analysis of the Keyboard Fault ....................................................................................... 18

2.2.4.2 Analysis of the Display Module Circle ............................................................................ 19

2.2.4.3 FM Module ..................................................................................................................... 20

2.2.4.4 Camera Module.............................................................................................................. 21

2.2.4.5 IO Interface .................................................................................................................... 22

2.2.4.6 SIM Card Circuit ............................................................................................................. 22

2.2.4.7 T-FLASH Card Circuit ..................................................................................................... 23

2.2.4.8 BT Circuit ....................................................................................................................... 23

2.2.4.9 WIFI Circuit .................................................................................................................... 24

2.2.4.10 GPS Circuit ................................................................................................................... 25

2.2.4.11 M-sensor Circuit .......................................................................................................... 26

2.2.4.12 G-sensor Circuit ........................................................................................................... 26

2.2.4.13 IR-sensor Circuit .......................................................................................................... 27

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1 Outline

Product Hardware Introduction

Base Chip Set

BB

MT6582V/X

PMIC

MT6323GA

Transceiver

MT6166

Camera DSP/MMP

NA

RFPA

SKY77590-11

FM

MT6627

BT

MT6627

Audio CODEC&PA

-

Memory

Samsung

TP IC

GT915

Peripheral

Configuration

LCD

-

Backlight Driver

RT8514

CAMERA

OV8830

Memory Card

TF Card

Antenna

monopole

Basic

Performance

Indicators

Leakage current

≤ 150uA

Standby current

≤ 7mA

Call current as

maximum power

TBD

Board-level power

EGSM

32.5dBm

GSM850

32.5 dBm

DCS

29.5dbm

PCS

29.5dbm

Band1

23dbm

Band8

23dbm

Board-level

receiver sensitivity

EGSM

-108dbm

GSM850

-108 dbm

DCS

-108 dbm

PCS

-108 dbm

1.1 MOBILE PHONE INTRODUCTION

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Band 1

-109.5 dbm

Band 8

-109.5 dbm

TRP

EGSM

28.8dbm

GSM850

27.0 dbm

DCS

28.0dbm

PCS

28.0dbm

Band 1

20.0dbm

Band 8

20.0dbm

TIS

EGSM

-105dbm

GSM850

-105dbm

DCS

-106dbm

PCS

-106dbm

Band 1

-107dbm

Band 8

-107dbm

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CPU

MT6582V/X

PMIC

MT6323GA

BATTRY

CAMERA

FM、BT、

WiFi、GPS

LCD：854*480

KEYPAD

T-FLASH

MEMORY

MT6166

SKY77590

-11

SPK

HP

REC

DUAL SIM
CARD

MIC

CTP

System Block Diagram

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1.2 Motherboard Components Distribution

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2 Signal Flow And Fault Analysis

A
N
T

PA &
Ant Switch

SKY77590

-11

Transceiver

MT6166

CPU
MT6582V/
X

MT6582V/X

MT6166

2.1 RF Part

2.1.1 Block Diagram of the RF Section

RF Diagram

GSM RF and BB interface diagram

2.1.2 Signal Flow OF the RF Transmitting Part

2.1.2.1 Receiving and Transmit Path

Receiving

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2.1.2.2 Maintenance Procedures of the Transmitting Part

（NO launch） Connect the PC and the phone with maintenance line,
then making the phone into the RF state with META software

Check Transceiver to see
if IO signals exist.

Check the PA output to

see if there is RF signal in

Y

Check CPU

N

Check RF coaxial

switch or matching

network.

Y

Check the Transceiver
to see if there is RF
signal output.

N

CheckVBAT,PA_EN,B
ANDSW_DCS,VAPC

Replace PA

Y

Check CPU

Y

Check Transceiver if LE、

SCLK/SDAT、RFVCOEN、

VCXOEN have the

correct signal.

N N

N

Y

Replace Transceiver

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2.1.3 Signal Flow of the Receiving Part

2.1.3.1 Receiving Part Components

2.1.3.2 Maintenance Procedures of the Receiving Part

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No receiving

Start the META software to connect the PC and the phone，making the phone into the receiving state.

Signal generator is also adjusted to the correspond CH. And signal lines connected to the phone.

Transceiver has IQ?

Check CPU

Y

Transceiver has received signal?

？

N

Transceiver

CSO,SCLK,SDATA are correct ?

Check CPU

N

Whether the voltage of

the transceiver is
normal? Whether

26MHZ is normal?

Y

Check the

corresponding power

supply and 26MHZ

resulting circuit

N

Replace transceiver

Y

PA has received

signal?

N

Check to see if there has
signal in the matching circuit
between PA and ANT

N

Check to see if there has
signal in the matching
circuit between PA and
transceiver

Y

Y

2.2 Baseband Part

2.2.1 Block Diagram of the Baseband Part

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CPU

MT6582V/X

PMIC

MT6323GA

BATTRY

CAMERA

FM、BT、

WiFi、GPS

LCD：800*480

KEYPAD

T-FLASH

MEMORY

MT6166

SY77590-11

SPK

HP

REC

DUAL SIM
CARD

MIC

CTP

2.2.2 Power Management Part

The power management Part use the special PMU IC : MT6323. Support 5-ways of DC-DC

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and 21-ways of LDO output, with AB/D, 0.7W Audio amplifier, LCD backlight driving and

Lithium battery charging circuit Inside it. Which support 5 LEDs in parallel and 10 LEDs in
series.

2.2.2.1 The Whole Power Supply System

DC-DC:

LDO

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2.2.3 Audio Part

2.2.3.1 Audio CODEC Circuit

Use AW8145 for audio PA

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2.2.3.2 MIC, RECEIVER LOOP

MIC Audio channel is shown below: This product uses the dual（OPTION）analog MIC in order to
reduce noise when you use voice calling. The power supply voltage is 1.8V-3.3V. When MIC is in
good condition but loop MIC has no echo, then you need to check the basic bias voltage signal of
the VMC, the language signals of the RECEIVER and MIC also need to be checked.

Receiver：

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2.2.3.3 HEADSET LOOP

Headset loop includes two signals: Headset speaker and MIC, the jack is SMT in the main-board.
If the Headset speaker has no sound、the MIC is invalid. All this need to check the SMT of the
J402

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2.2.4 BASEBAND FAUIT ISSUES

Download Fail

Check to see if it is caused by other
factors such as: configuration,
download cable, power supply,

Exclude the reason of
download failure
caused by other

Yes

Check to see if the serial ports between
pc and cell phone is smooth

Check if the system
connector is poor
soldered or damaged.

NO

NO

Check the resistance,
capacitance and the
EDC devices between
the system connector
and the CPU.

NO

Connect the download cable then
observe the Ammeter to see if it
shows high current（The normal
current generally about 30mA）

Yes

Quickly disconnect the
connection, and gently
touch the chip to see if it is
hot. If not, then focus point
using the multi-meter to
measure the short circuit.

Yes

Check the power manager and open the
LDO to see if the voltage supply is
normal and whether there is power
supply circuit open.

Little or no current

Check VCORE、VDD、VADD、VTCXO、VRTC、
VMEM、Measure the clock signal of 26MHZ、
32KHZ.

Current normal but download fail

Check CPU and NAND FLASH、SDRAM to see
if they are OK and the LDO is normal.

Maintenance process of the download failure Issues:

2.2.4.1 Analysis of the Keyboard Fault

This board includes 3 side-buttons. All the keyboard circuits use the scanning method to detect
except the power button, volume up and down. The scanning signal will be triggered when a
button is pressed,, then the corresponding row and column will be detected, the function of the
key can be identified according to the software definition.

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a. The cell phone can power on ，but all the keys are invalid.

In general, this situation is caused by some key short-circuit, the equivalent of a long
pressing this button.
At this point ,you should analyze the following first：

⑴ Check peripheral TVS of the button to see if they are short-circuit.
⑵ Then ,check the connector to see whether it is short-circuit when it is welded.

b. Failure of a single button

This situation needs to check whether the beneath of the DOME key is dirty. If the
problem is still existed, you have to check whether the circuit is open.

c. Failure of a few buttons

This situation is usually caused by a short-circuit row or column. Checking the

interface circuit to see if it has open weld phenomena and detect the disconnected
phenomena of the resistance.

2.2.4.2 Analysis of the Display Module Circle

Display module use the 4.3" LCD, which including 2 pairs MIPI differential bus mode. All of
commend and data go through the MIPI differential bus mode except the reset signal.

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For the screen problem you should first use the alternative method to search out whether the
problem is in the motherboard or the LCD. Focus on examining the LCM connector and EMI filter
welding.. The backlight signal is completed by the LED driver chip AW9910STR. Generally,
measure the input voltage VBAT and the enable control signal.

2.2.4.3 FM Module

The WIFI Circle is based on chip MT6627, comes with FM module and transmitter function, also
with both analog and digital audio channels choose from. The RF part supply short antenna
design and long antenna design.

The FM interface Circle as shown below:

FM use the headphone ground as the antenna，therefore the headset ground and the
motherboard ground have1000@100M magnetic beads to isolate FM(80M~108M)signals.

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2.2.4.4 Camera Module

The module uses 5 million pixel AF camera as the main camera, 0.3 million pixel camera as the
sub camera. Through the connector and the baseband chip (the main camera series EMI devices)
directly connected.

The Camera Interface Circuit as show below:

The Camera Power Supply Circuit
The VCAM_IOPMU supply 1.8V to Camera IO interface voltage, VCAMA_PMU supply 2.8V analog

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voltage.

2.2.4.5 IO Interface

2.2.4.6 SIM Card Circuit

Switch of dual SIM cards is integrated into baseband, which supports dual SIM Card function,
SIM1 support GSM/WCDMA Card, SIM2 support only GSM Card.. As show below:

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2.2.4.7 T-FLASH Card Circuit

The T-FLASH Card Circle support data exchange between Phone and PC. The Circuit have four
serial data transmission lines （ MCODA0,MCODA1,MCODA2,MCODA3 ） and state
detection(MCOCMD),CLOCK(MCOCK),as the show below:

2.2.4.8 BT Circuit

The Bluetooth function is one part of the MT6627 .The BT Circuit include baseband, RF unit,
UART2 unit, PCM interface system configuration, and also.

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2.2.4.9 WIFI Circuit

The WIFI Circuit integrated in MTK6627, The WIFI Circuit includes baseband, RF unit, power,
SDIO interface system configuration. It supports 2.4G, following 802.11b/n/g agreement,
supports safety format is WFA, WPA/WPA2, WPS2.0, WAPI.
The WIFI’S RF interface is connected with external antenna. The ANT is transmitting or receiving
signals to communicate with WIFI equipment.

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2.2.4.10 GPS Circuit

The GPS Circuit integrated in MTK6627, It includes baseband, RF unit, power, UART interface
system configuration. Its sensitivity supports 165dBm, supports AGPS.

The GPS’S RF interface is connected with external antenna. The ANT is receiving GPS satellite

signal to achieve positioning. GPS and BT share the same ANT. We switch GPS signal by the
switch U904, then through a narrowband filter U903(OPTION) into GPS chip.

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2.2.4.11 M-sensor Circuit

M-SENSOR is a electronic compass, it supports X, Y, Z three-axis orientation sensor. M-SENSOR
uses I2C to connect CPU interface, in order to transmit directives and data.

2.2.4.12 G-sensor Circuit

G-SENSOR is a sensor of acceleration due to gravity. It supports X, Y, Z three-axis orientation
sensor. M-SENSOR uses I2C to connect CPU interface, in order to transmit directives and data.

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2.2.4.13 IR-sensor Circuit

IR-SENSOR is light &distance sensor. It induces current phone the environment in which of the

brightness and Perceived distance of the human face in the phone calling and the phone.

IR-SENSOR uses I2C to connect CPU interface, in order to transmit directives and data, also we

need an INT give CPU a trigger signal.

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3. Disassembly and assembly service Tools

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