FLY E155 Service Manual

E155 Service Manual

Prepared by：Jianing Wen Approved by： Date：2010.7.2

1 Overview E155

cacy

1.1 About E155 Phone

1.2 Distribution of the mainboard components

2 RF

2.1 RF Overview

2.2 Transmit

2.3 Receive

2.4 Common RF Malfunction

3 Baseband

3.1 Baseband Overview

3.2 Logic

3.3 Power management

3.4 Baseband common malfunction

4 Reference for maintenance

4.1 No power on

4.2 Shut off automatically

4.3 Dead halt

4.4 No charge

4.5 Quantity of electricity faulty detection

4.6 No display

4.7 LED NG (on the LCD)

4.8 LED NG (on the key board)

4.9 Key NG

4.10 No ring

4.11 No receiving voice

4.12 No sending voice or the voice is small

4.13 No vibration

4.14 Card inefficacy

4.15 Camera inefficacy

4.16 Bluetooth circuit(MT6612)

4.17 TF card inefficacy

4.18 Earphone inefficacy

4.19 FM inefficacy

4.20 G-senser ineffi

1 Overview E155

1.1 About E155 Phone

E155 mainboard is based on the MTK platform designed to support 2-band

which supporting the FM and Bluetooth calls and transmission, and Wifi, the mainboard system consists of the base-band （CPU： MT6235+TY9A0A111179KC40） and the RF (MT6140+SKY77546).

1.2 Distribution of the mainboard components

TF Card

Audio PA

CPU

MT6235

Wifi

Battery CONN

S200

Adapter CONN

Blue toothes

Antenna connecter

MT6212

TY9A0A1111 79KC40

Flash

SIM1

Socket of SIM card

SIM2

Earphone CONN

MOT

Camera connecter

TP connect interface

K/B FPC

LCD

Transceiver

RF PA

MT6140

SKY77546

MIC

AR1010

Receiver

MMA7660FC

3D G-Sensor

2 RF

2.1 RF Overview RF part mainly consists of transceiver MT6140 (adopts program of near-zero IF

receiver, supporting the EGSM / DCS and 26M VCTCXO as the clock input, integrated clock buffer, LO VCO and TX VCO and regulator, only need for external connections of VBAT / AVDD), SKY77546 (it supports EGSM / DCS and integrated automatic power control and transceiver switch).

Transceiver (MT6140) with the RF modulation and demodulation functions

contains IF frequency synthesizer and VCO RF, which is part of the core component of the RF. PA has a major role in amplification of modulation signal, and it must be controllable and the speed should meet the GSM agreement.

2.2 Transmit TX is composed of the modulation loop, power amplifier and antenna

switch. PLL is mainly in the internal MT6140, I / Q signal first enters into the MT6140, after entering the PLL the signal is modulated to RF, and then it outputs from the chip to PA, converts into electromagnetic energy through antenna by the antenna

switch after enlarged. PA: This part adopts voltage control to achieve and its role is to amplify

the signal power in accordance with the requirements. It is divided

to two different power levels through VRAMP signal. The transmit

signal of GSM is 5 to 19, power is from 3.2MW to 2W while DCS is

0 ~ 15, power from 1MW ~ 1W. PA is time-sharing work controlled

by TX-EN chip, the output power of PA is controlled by VRAMP

(APC) through the voltage. PA is intermittent work, by the BS to

achieve the choice of frequency bands.

2.3 Receive Antenna RX - MT6140 (RX_VCO mixer) - band-pass - Amplification -

filter - Amplification - RX_VCO mixer - CPU

2.4 Common RF Malfunction Detection and Maintenance Flow Chart of MS Transmit malfunctio

3 Baseband

3.1 Baseband Overview

E155 Baseband consists of CPU MT6235 and Program Memory. UMT6235 baseband, the core device of the mainboard, is responsible for the normal work among various parts of mainboard, such as voice processing, image processing, power management as well as MS communications.

UMT6235 digital baseband contains 32-bit ARM7E core and 284Kbyte SRAM. MT6235 which is an enhanced GSM Processor integrated Channel Codec subsystems interiorly including Channel Codec, Intertlace / Deinterleave, Encryption / Decryption and Control Processor subsystems including ARM7EJS and its peripheral circuits. There are 26 address lines,16 data lines, 8 chip select lines, provided 6 external interrupt Interface, 26M/52M operation clock.

Analog baseband contains UMT6235 analog baseband chip, audio, baseband codec and power management. Four major functional blocks integrated internal: Audio codec including Voice input / Output channel, Buzzer output; Baseband codec including Differential I, Q input / output, GMSK modulation and A / D, D / A; Auxiliary parts including AFC DAC, RAMP DAC, AGC DAC and a seven-channel A / D. And WATCHDOG interface is set internal to enhance the stability of the system.

3.2 Logic

Logic part is composed of MTK base-band management chip UMT6235, power management chip MT6235 and Nand Flash.

 UMT6235：CPU  Nand Flash：TY9A0A111179KC40  MT6235：PMU

3.3 Power management

Power management consists of the charging circuit integrated in MT6235 and the external charging circuit. It provides 11 road LDO voltage. Besides, it completes the logic level conversion of SIM card. The chip also outputs the system reset signal.

Boot process: The normal boot is to press boot key which is that the PWRKEY is being dragged down. Once the boot key is pressed, all LDO are open except VSIM. After VCORE opening RESET timer and timer out, RESET is being pitched up to start the digital baseband chip, that is, UMT6235 starts to run and roll polling its ROWX pin, pitch up its PWRONIN pin, then you can release the boot key. This is the initial boot process.

3.4 Baseband common malfunction

3.4.1 Nand Flash programming does not download

Data lines used for downloading software: VBAT, TX, RX, GND, CHARGE. It is mostly due to the false solder and wire bonding. First check whether the serial port of PC and cell phone is unrestricted, if not, it is caused by being lack of devices or empty solder of power manager, USB-con and peripheral resistance. Measure the TX, RX signals by using AC-coupled oscilloscope to track the signal flow, if a certain period circuit of no signal it may be AC short circuit to ground, or is caused by a short circuit and open circuit. On checking the malfunctions, first should carefully observed the welding of these devices with a magnifying glass, then plug in the download line to observe whether the current is normal, there is short-circuit to ground of VCHG or VBAT if the current is large, at this time cut off power supply as soon as possible, and then find the short-circuit point. It may be the abnormal output power supply of a certain circuit that the current is larger than normal (about 30 mA) but not particularly large, at this time should check whethe the valgate of VCORE (1.8V), VDD (2.8V), VADD (2.8 V), VTCXO (2.8V), VRTC (1.5V), VMEM (2.8V) is noamal, if not, bad welding can be detected. Focus on checking the welding of PMU and USB-CON if there is a little or no current. Unplug and re-plug the download line to see if it is caused by poor contact; It can test that whether the output of 26MHz clock signal to the CPU is normal by using oscilloscope.

3.4.2 Detection and Maintenance Flow Chart of No download malfunction

4 Reference for maintenance

4.1 No power on

No power on

Check whether the

battery voltage is

higher than 3.4V

Check whether the battery and the key pad of J404 is

oxidized or there is

anything else on it

Charge the battery

Wipe off the thing

or clean the key pad

Check whether the

connection of K/B &

M/B is OK

Take out the LCD and

SPK, Check whether it is

powered on

reweld the K/B

Cross-testing the

LCD&SPK,

Change the defective

C1128:1.8V,

C1139:1.25V,

C1131:2.8V, C1132:2.8V, C1133:2.8V,

Check whether

R1114,D4413,D4432 is

broken

Connect with the battery,

press “NO” key, check

whether the output voltage

of U1100 is normal

Check whether the

output frequency of

X1100 is 32.768K

Change the

FLASH(U1302) of the

main module, check

whether it is OK

capacitor corresponding to

Change R1114,D4413,D4432

Replace a earthed

the defective pin, Check

whether it is OK

Change X1100，

Change U1100

C1105，C1106

Change U1302

4.2 Shut off automatically

Shut off

automatically

D/L the latest edition,

Check whether it is OK

Replace with a

good battery, Check

whether the

primary cell is broken.

Check whether the

rubber, used to fix the

battery, is lost or at the

other location

Check whether the battery

and the key pad of J9435 is

oxidized or there is

anything else on them

Change the battery

Reassemble the

rubber

Wipe off the thing

or clean the key pad

Check whether the

battery connector ‘J9412 is

void-welded or broken

Check whether the

connection of J9410,J9402,J9403

&K/B FPC is OK,FPC is

void-welded

Re-weld or

change J9412

Reassemble the K/B

Or change the FPC

Check whether X1100

output frequency is

32.768K exactly

Refer to the maintenance

method of ‘No power on’

Change X1100，

C1105，C1106

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