FLY EZZY 3 User manual

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FLY EZZY 3
SERVICE MANUAL
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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
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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 3 provides you with a collection of practical
Functions including sweet ring tone, cartoon incoming-call animation, File manager
(T-Flash card support). It also supports MMS and increment service which facilitate your work and
entertainment.
In order to support technicians to be familiar with FLY EZZY 3 handset, please master the method of servicing.
In addition, we provide corresponding technical data, including CKT base band, RF and software. There are
also many base band and RF test reference points and description of circuit. You can refer to maintaining
examples. Hope it could give you some help.
Main specification and technique standards of FLY EZZY 3 are as below:
Standby time:
Talking time:
Style of network
160-240 hours-
160-200min
GSM900, DCS180
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The main board placement
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Chapter 3: Explanation of Schematic
MTK6253
MT6253
MTK6253
Picture 3.1 MT6253 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 .
SKY77542
CPU
MT6253
Transceiver
MT6253
bring
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RF Circuit deals with the RX and TX of wireless signal, with responsibility for the bidirectional
Transmission of speech and data between the MS and BS through the air interface. In detail RX part
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. The
Performance of RF Circuit can directly affects the signal transmission quality of the mobile phone!
The schematic of RF block for MTK GSM Dual-band RF solution is show below:
From the chart we can see that the RF part is mainly composed of a highly integrated CMOS
Transceiver chip (MT6253), some RX Saw filters, reference crystal oscillator, power amplifier,
Antenna switch module, antenna and the matching components between each other...
3.1.2 Direct Conversion Receiver
-Differential LNA
-Integrated Active RX Channel Select Filters
-Programmable Gain Baseband Amplifiers
-The receive path
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RX Saw filter Circuit
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 Down-
Converting Mixer and the Quadraturemodulator
TX PA: SKY77542
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TX PATH:
3.14 26MHz Clock:
-The entire system including VCO, tank, fractional N dividers, sigma delta compensation, charge pump and
loop filters are fully integrated.
-The only external component is the frequency reference.
26MHz Clock Reference circui
3.1.5 High performance multi band PLL system
-Fast Fractional-N Synthesizer
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-Integrated Local Oscillator VCO
-Fully Integrated Loop filters
-Crystal Reference Oscillator & Tuning System
3.1.6 Power 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
DCS 1800 925.2MHz ~ 959.8MHz 1805.2 MHz ~ 1879.8MHz
The frequency ranges of the synthesizer for TX mode
TX mode
EGSM900
DCS1800 880.2MHz ~ 914.8MHz 1710.2 MHz ~ 1784.8MHz
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3.1.3 MT6253 Function Block Diagram
MT6253
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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 MT6253 and periphery components, main function as below:
A.
B.
C.
D.
E.
F.
G.
H.
I.
J.
K.
I.
M.
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
Li-Ion battery charge function
SIM Card interface
Two open-drain output switches to control the LED and vibrator
Three NMOS switches to control RGB LEDs
Thermal Overload Protection
Under Voltage Lock-out Protection
Over Voltage Protection
Power-on Reset and Start-up Timer
MT6253
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1．7 channel power supply
MT6253 7 channel power supply:
LDO
VCORE
VDD
AVDD
VCTXO
VMEM
VSIM
VRF
Power
1.8V/1.5V
2.8V
2.8V
2.8V
1.8V/2.8V
1.8V/3.3V
2.8V
2、power on/off circuit
Function
Digital core voltage LDO output
Digital I/O voltage LDO output
Analog LDO output
Crystal or VCTCXO LDO output
External memory LDO output
LDO output to SIM card
LDO for RF transceiver
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After the handset power off, the pin PWRKEY is pulled high. The pull-up resistance is inside the
chip .When the power key is pressed, the pin PWRKEY is pull low, then the MT6253 turn on all the Power supply
function and the baseband chip enter working status. So the pin BBWAKEUP is pulled high. At that time, the power
key can be released; the CPU-baseband chip can control the MT6253.
Charge Circuit
MT6253 charge management function:
1、Charger detection
2、Battery voltage measurement
3、Charging current measurement
4、Over voltage Protection
5、Charge mode selection
MT6253 is available to control the pulsed charging current. The pin CHRIN is to detect the
Charger. The pins ISENCE/BATSENES can calculate the battery voltage by detect the voltage of R400, and calculate
the charge current by the voltage of the resistance R400. In different charge mode, Baseband chip sent the
different PWM pulse signal to MT6253, so the MT6233Acan control the process of charge.
The charge process include three states: pre-charging mode, constant current mode and constant voltage
Mode. If the battery voltage is bellow 3.2V, the handset enter pre-charging mode; If the battery voltage
is over 3.2V, it enter the constant current mode; If the battery voltage is higher than 4.2V, it enter the
constant voltage mode
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3.2.3 SIM interface
SIM interface circuit
The power management chip supply the interface between the SIM card and baseband chip, the
Key signal is: SIM_CLK (the clock signal), SIM_RST (the reset signal), SIM_I/O (I/O signal),
VSIM (SIM power supply).
3.2.4 Principle of audio frequency circuit
The Audio Frequency (AF) circuit includes three parts: RECEIVER and SPEAKERs, HANDSET
MIC, ERAPHONE and HANDFREE MIC.
There are 4 speakers; each speaker is drove by an AF amplifier. The baseband chip sends the AF
Signal to the AF amplifier though MP3_OUT port. After the AF signal is amplified, it goes to the
Speaker. The RECIEVER is drove by the baseband chip directly. As an electrets tone arm, the MIC
Needs power support when working. The MICBIASP/N port of the baseband chip supports bias
Voltage for Mic. The EARPHONE port of the FLY EZZY 3 is dual-used with the USB port. For more details
Please refer to "communication ports" in later part.
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1、Receiver
Figure 3.2.5 Circuit of receiver
2、Louder speaker
Figure 3.2.6 Circuit of louder speaker
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3、Handset microphone Earphone
Figure 3.2.7 Circuit of MIC bias voltage circuit of mobile phone
4、Hands-free microphone
Figure 3.2.8 Circuit of Hands-free microphone
3.2.5 LCD circuit
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Memory and all the periphery equipments used the same bus based on the 1 generation base band chip
That made the system very slow. Considering that, MTK have altered the hardware structure to separate
The periphery equipments (like LCD and NAND etc.) from memory bus and all of them use the 52M
System clock simultaneously
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Figure 3.2.9 LCD interface circuit
LCD use series type LCD and four control bus (LPCEOB_MAIN_LCM is chip select signal; LPA0 is select
bus for register and commend; LWRB is LCD writes strobe; LRDB is LCD read strobe, LRSTB is reset signal.
LCD is controlled by baseband IC.
Display data is transferred to video RAM in LCD driver by I/O port in DMA mode. So system
Can response quickly and multimedia runs fluently without mosaic or picture feeling. Three
Common-anode LEDs in charge of background light supplying. Three voltage sensitive resisters are
Needed to protect the LCD from electrostatic harm and extend the l
ife of LCD.
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3.2.8 T－Flash circuit
T-Flash card interface: VDD is supplied by MT6253
3.2.10 FM
U604 is the FM chip to supply the function of FM radio.
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3.2.11 key interface
When key is pressed down, the matrix KCOLX status is pulled down to low. Interrupt occurs,
Then Baseband can judge the key's location, so system implements corresponding function.
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