FLY EZZY Service Manual

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FLY EZZY

SERVICE MANUAL

CONTEANT LIST
Chapter 1: Summary
Chapter 2: Exploding Diagram
Chapter 3: Explanation of Schematic
Chapter 4: Failure Analysis
Chapter 5: Manual of tool software

Chapter 6: Tools List

Chapter 1: Summary

This streamline and comfortable handset is a perfect combination of humanized design and
Excellent craft. Besides the basic call function, FLY EZZY provides you with a colle
Functions including sweet ring tone, cartoon incoming-call animation, File manager
(T-Flash card supp

ort). It also supports MMS and increment service which facilitate your work and

entertainment.
In order to support technicians to be familiar with FLY EZZY handset, please master the method of servicing.

In addition, we provide corresponding technical data, including CKT base band, RF and software. There are

ction of practical

also many base band and RF test reference points and
examples. Hope it could give you some help.

Main specification and technique standards of FLY EZZY are as below:

Standby time:

Talking time:

Style of network

description of circuit. You can refer to maintaining

160-240 hours-

160-200min

GSM900, DCS180

Chapter 2: Exploding Diagram

The main board PCB

The main board placement

Chapter 3: Explanation of Schematic

AD6548

MTK6223A

MTK6223A

Picture 3.1 MT6223A principle picture

3.1 Principle of RF circuit

3.1.1 Principle of receiver circuit

3.1.1.1Rx signal flow chart:

Picture 3.1.1 Receive signal flow frame

3.1.1.2 Main function of RF

RF part generally means the analog RF and IF process system ,including Antenna system、

TX path、RX path、Analog modem and Frequency Synthesizer .

RF Circuit deals with the RX and TX of wireless signal, with responsibility for the bidirectio

Transmission of speech and data between the MS and BS through the air interface. In detail RX part

nal

Accomplishes the AGC amplifying, mix and demodulation of RF weak signal received from BS, The
Final signal output from RX part is the analog baseband I/Q signal. The final RX I/Q will be sent to
Baseband Circuit for later disposal. On the other hand TX part deals with the signal modulation,
Up-conversion mix and power amplifying of analog I/Q signal received from baseband, generating
Burst which meets the GSM specification. And then the bursts are transmitted to Base station through
The antenna. The signal interface between RF Circuit and Baseband is analog baseband I/Q signal. T
Perfo ile phone!

rmance of RF Circuit can directly affects the signal transmission quality of the mob

The schematic of RF block for MTK GSM Dual-band RF solution is show below:

he

From the chart we can see that the RF part is mainly composed of a highly integrated CMOS

Transceiver chip (AD6548), some RX Saw filters, reference crystal oscillator, power a
Antenna switch module, antenna a

3.1.2 Direct Convers

ion Receiver

nd the matching components between each other...

–Differential LNA

–Programmable Gai

–Th receive path

e

RX Channel Select Filters–Integrated Active

n Baseband Amplifiers

mplifier,

3.1.3 Translation Loop Direct VCO Modulator
–Integrated TX VCO and tank

–External TX filters eliminated
–Integrated Loop filter components
–Transmit Path

AD6548 uses only a single VCO source to derive the local oscillator signal for both the Feedback Down­Converting Mixer and the Quadraturemodulator

TX PA: SKY77542

RX Saw filter Circuit

TX PATH:

3.14 26MHz Clock:
–The entire system including V

loop filters are fully integrated.

The only external component is the frequency reference.

–

CO, tank, fractional N dividers, sigma delta compensation, charge pump and

26MHz Clock Reference circui

3.1.5 High performance multi ban
–Fast Fractional-N Synthesizer

d PLL system

Integrated Local Oscillator VCO

–
–Fully Integrated Loop fil

ters

–Crystal Reference Oscillator & Tuning System

.1.6 Po

3 wer Management

Integrated LDOsallow direct battery supply connection

–

3.1.7 Frequency ranges

The frequency ranges of the synthesizer for RX mode:
RX mode

E-GSM 900 925.2MHz ~ 959.8MHz
DCS 1800 1805.2 MHz ~ 1879.8MHz

The frequency

ranges of the synthesizer for TX mode

TX mode

EGSM900 880.2MHz ~ 914.8MHz

DCS1800 1710.2 MHz ~ 1784.8MHz

3.1.3 AD6548 Function Block Diagram

3.2Principle of base band circuit

3.2.1 Whole introduction of base band circuit

3.2.2 Explanation of power circuit and in-and-out circuit

Power source is provided by MTK MT6223A and periphery components, main function as below:
A.
B.
C.

D.
E.

2.8V-5.5V Input Range
Charger input up to 8V
Seven LDOs optimized for specific GSM Sub-systems

One LDO for RF transceiver

High operation efficiency and Low stand-by current
F. Li-Ion battery charge function
G. SIM Card interface
H. Two open-drain output switches to control the LED and vibrator
I. Three NMOS switches to control RGB LEDs
J. Thermal Overload Protection
K. Under Voltage Lock-out Protection
I. Over Voltage Protection
M. Power-on Reset and Start-up Timer