mobile servicing

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SYLLABUS:

COMMUNICATION SYSTEMS

SIMPLEX

HALFDUPLEX

FULLDUPLEX

MOBILE PHONE HISTORY

MOBILE GENERATIONS

1G

2G

3G

4G

BASICS OF ELECTRONICS

RESISTOR

CAPACITOR

INDUCTOR

DIODE

TRANSISTOR

IC

LED

LCD

OSCILLATOR

POWER SUPPLY UNIT

VOLTAGE

CURRENT

POWER

E.M.F

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POWER SUPPLY CIRCUIT

TRANSFORMER

RECTIFIER

FILTER

REGULATOR

CELLULAR COMMUNICATION

MOBILE COMMUNICATION

WIRELESS COMMUNICATION

INFRARED

BLUETOOTH

VIRUS

MOBILE LOCKS

PCB DIAGRAM

TROUBLE SHOOTING

MOBILE PARTS

GLOSSARY OF TERMS

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COMMUNICATION SYSTEMS:

Simplex:

Simplex communication refers to communication that occurs in one direction

only.

Examples:

Commercial radio broadcast (not walkie-talkies, etc.)

Television broadcast,

Internet multicast.

Half-duplex:

A half-duplex system provides for communication in both directions, but only one

direction at a time (not simultaneously). Typically, once a party begins receiving a signal,

it must wait for the transmitter to stop transmitting, before replying.

Examples:

walkie-talkie (since, it is two-way radio, wherein one must use "Over" or

another previously-designated command to indicate the end of transmission, and ensure

that only one party transmits at a time, because both parties transmit on the same

frequency.)

Full-duplex :

A full-duplex, or sometimesdouble-duplex system, allows

communication in both directions, and,

unlike half-duplex, allows this to happen

simultaneously. Land-line telephone networks are full-duplex, since they allow both

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callers to speak and be heard at the same time. A good analogy for a full-duplex system

would be a two-lane road with one lane for each direction.

Examples:

Telephone,

Mobile Phone, etc.,

MOBILE PHONE HISTORY:

In the year of 1973, a former general manager from the systems division of

Motorola, Dr. Martin Cooper, became who is thought to be the inventor of the first

portable handset. Dr. Cooper was also the first person to make a call using a portable cell

phone.

In New York, he set up a base station with the first

working prototype of a cell phone, the Motorola Dyna-Tac.

He and Motorola took this technology to New York to show

the public.

Later on, in 1977, the cell phone went public and public

testing began. Chicago was the home for the first trials with

2,000 people. After Chicago, there were later trials in

Washington, D.C. and Baltimore, and then it spread to Japan in 1979. Usual technologies

changed in 1988 when the CTIA - Cellular Technology Industry Association - was

formed to lay out realistic goals for cell phone providers. Research for new applications

of development was included.In 1991 the Telecommunications Industry Association set a new standard with the

creation of the TDMA Interim Standard 54.

Cell phones have had quite a long journey. Although there was a great demand for

cell phones, it took 37 years for them to become commercially available in the United

States.

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Wireless service was actually invented almost 50 years ago, so it's hard to believe

that cell phones have only become popular over the past couple of decades. Currently,

there are more than 60 million people who own cell phones.

In the communications world, the Motorola brand brings to mind innovation.

Years of experience engineering portable two-way radio systems led to Motorola's vision

of personal, portable communications. The result was the world's first commercial

portable cellular phone in 1983. Motorola's DynaTAC 8000X phone and the cellular

system behind it changed how the world communicates.

MOBILE GENERATIONS:

0G:

0G refers to pre-cell phone mobile telephony

technology, such as radio telephones that some had in

cars before the advent of cell phones.

One such technology is the Autoradiopuhelin (ARP)

launched in 1971 in Finland as the country's firstpublic commercial mobile phone network.

1G:

1G (or 1-G) is short for first-generation wireless telephone technology, cell

phones. These are the analog cell phone standards that were introduced in the 80's and

continued until being replaced by 2G digital cell phones.

One such standard is NMT (Nordic Mobile Telephone), used in Nordic countries,

Eastern Europe and Russia. Another is AMPS (Advanced Mobile Phone System) used in

the United States.

Antecedent to 1G technology is the mobile radio telephone, or 0G.

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2G:

2G (or 2-G) is short for second-generation wireless telephone technology. It

cannot normally transfer data, such as email or software, other than the digital voice call

itself, and other basic ancillary data such as time and date. Nevertheless, SMS messaging

is also available as a form of data transmission for some standards.

2G is the current generation of full digital mobile phone systems. It transmits

primarily voice but is used for circuit-switched data service and SMS as well. 2G services

are frequently referred as Personal Communications Service or PCS in the US.

2G technologies can be divided into TDMA-based and CDMA-based standards

depending on the type of multiplexing used.

The main 2G standards are:

GSM (TDMA-based), originally from Europe but used worldwide

IS-95 aka cdmaOne, (CDMA-based, commonly referred as simply CDMA

in the US), used in the Americas and parts of Asia

2.5G :

2.5G is a stepping stone between 2G and 3G cellular wireless

technologies. The term "second and a half generation" is used to describe

2G-systems that have implemented a packet switched domain in addition

to the circuit switched domain. It does not necessarily provide faster

services because bundling of timeslots is used for circuit switched data

services (HSCSD) as well.

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While the terms "2G" and "3G" are officially defined, "2.5G" is not. It was invented for

marketing purposes only.

3G:

3G (or 3-G) is short for third-generation mobile telephone technology. The

services associated with 3G provide the ability to transfer both voice data (a telephone

call) and non-voice data (such as downloading information, exchanging email, and

instant messaging).

3G Standards:

3G technologies are an answer to the International Telecommunications Union's

IMT-2000 specification. Originally, 3G was supposed to be a single, unified, worldwide

standard, but in practice, the 3G world has been split into three camps.

UMTS (W-CDMA)

UMTS (Universal Mobile Telephone System), based on W-CDMA technology, is

the solution generally preferred by countries that used GSM, centered in Europe. UMTS

is managed by the 3GPP organization also responsible for GSM, GPRS and EDGE.

FOMA, launched by Japan's NTT DoCoMo in 2001, is generally regarded as the world's

first commercial 3G service. However, while based on W-CDMA, it is not generally

compatible with UMTS (although there are steps currently under way to remedy the

situation).

CDMA2000

The other significant 3G standard is CDMA2000, which is an outgrowth of the earlier 2G

CDMA standard IS-95. CDMA2000's primary proponents are outside the GSM zone in

the Americas, Japan and Korea. CDMA2000 is managed by 3GPP2, which is separate

and independent from UMTS's 3GPP.

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TD-SCDMA

A less well known standard is TD-SCDMA which is being developed in the People's

Republic of China by the companies Datang and Siemens. They are predicting an

operational system for 2005.

List of countries that have deployed 3G:

Australia (W-CDMA) (CDMA2000 1x)

China (CDMA2000 1x)

Germany (W-CDMA)

India (CDMA2000 1x)

Indonesia (CDMA2000 1x)

Japan (W-CDMA, CDMA2000 1x)

Russia (CDMA2000 1x)

Singapore (W-CDMA)

South Africa (W-CDMA in testing)

United Kingdom (W-CDMA)

United States (CDMA2000 1x) (W-CDMA in testing)

BASICS OF ELECTRONICS:

Resistor:

Denoted by R,

Symbol:

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Unit: ohm ()

Function:

It is used to oppose the flow of current or drop the voltage.

Ohm's law

The behavior of an ideal resistor is dictated by the relationship specified inOhm's law:

V= IR

Ohm's law states that the voltage (V) across a resistor is proportional to the current (I)

through it where the constant of proportionality is the resistance (R).

Series and parallel resistors

Parallel resistors:

Resistors in aparallelconfiguration each have the same potential difference (voltage). To

find their total equivalent resistance (Req):

The parallel property can be represented in equations by two vertical lines "||" (as in

geometry) to simplify equations. For two resistors,

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Series resistors:

The current through resistors in series

stays the same, but the voltage across

each resistor can be different. The sum

of the potential differences (voltage) is equal to the total voltage. To find their total

resistance:

Capacitor:

Denoted by C,

Symbol:

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Unit: farad (f)

When an insulator is placed between two conducting parallel plates, then it acts as

a capacitor.

Function:

It acts as a storage device,

It acts as a filter.

Inductor:

Denoted by L,

Symbol:

Unit: Henry.

Function:

It is used to receive the signal and

oppose the change of direction of flow of

current.

Diode:

Denoted by D,

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Symbol:

Function:

Diode acts as a rectifier, that it converts A.C into D.C.

Bridge rectifier is used in the charger circuit for rectification purpose.

It works only on the forward bias, it will not work on the reverse bias. It has a PN

junction layer.

Transistor:

Types of Transistors, NPN, PNP.

Symbol:

NPN : PNP :

It has three terminals, that is Collector, Base, Emitter.It has two PN junction layer.

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EMITTER

It is a region which supplies charge carriers to the other two region hence it is a

heavilyDoped region.

BASE

The base of the transistor is thin and it is lightly doped region.

COLLECTORThe collector of the transistor is always larger than the emitter and base of the

transistorHence the Doping level in intermediate between the heavy doping of emitter and the light

doping of base.Function :

It acts as a switch.

IC :

Integrated Circuit, has many advantages some of them are as follows,

Advantages :

Less in size, Requires low

operating voltage, Low cost.

Dis-advantage :

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W e cant Troubleshoot the problem occurred in the IC.

In case of any damage the whole IC should be replaced.

LED :

Light Eitting Diode.

Symbol:

The operating voltage range for an LED is (1.3-3 Volts).

It gtlows only on the forward bias, it will not work on the reverse bias

It is used in the key pad as a light.

LCD :

Liquid Crystal Display.

It is used in the mobile as a Display.

Oscillator :

It is an electronic device used to produce a repetitive electronic signal. that is,

frequency/pulse.

POWER SUPPLY UNIT:

Voltage:

Difference between two potential point is called as voltage. Its unit is volts(V).

VOLTAGE CONNECTION IN SERIESVoltage is sum of voltage and the current in constant.

Volt = 2V+2 V = 4V

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VOLTAGE CONNECTION IN PARALLELIn this parallel connection voltage remains constant but the current is this

summation of current.

Current:

Flow of electrons in a conducting material in one direction is called as current.

Its unit is Amphere(I).

Power:

Product of voltage and current is called as Power. Its unit is watts.

Power = V*I..

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E.M.F:

Electro Motive Force is the force required to move the electron in a conducting

material

POWER SUPPLY CIRCUIT:

Power supply circuit is also known as Charger circuit.

It requires the following things,

TRANSFORMER

RECTIFIER

FILTER

REGULATOR

TRANSFORMERThe function of transformer is, it will transforms the AC voltage from the primary

coil to the secondary coil without change in the frequency.

There are two type of transformer, they are

Step down transformer

Step up transformer

IN THE STEP DOWN TRANSFORMER

The primary coil winding is greater than the secondary coil.The voltage in the primary will step down to the secondary.

Ex: In a 230V to 20V AC transformer.If 230 V AC is given to the primary of the step down transformer the output from

the secondary will be 20 V AC. But the frequency remains 50Hz.

IN THE STEP UP TRANSFORMERThe primary coil winding is lesser than the secondary coil winding.

The voltage in the primary will step up to the secondary.Ex: If 180 V AC is given to the primary of the transformer than the output voltage

in the secondary will be more than that. But the frequency remains constant.

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RECTIFIERRectifier is used to convert the AC (Alternating Current) to the DC (Direct

Current). Diode acts as a rectifier, here in this power supply circuit, Four diodes D1, D2,D3, D4 are used as a Bridge Rectifier.

The output from the secondary of the transformer is given as the input for the

bridge rectifier.which converts the AC to DC then the output obtained from the BridgeRectifier is a DC Voltage.

FILTER:Filter is used to filter the AC component present in the DC and the output from

the filter circuit is a pure form of DC voltage.

Here Capacitor acts as a filter.

REGULATOR:Regulator an IC which is used to maintain a constant voltage at the output

TYPES OF REGULATOR: Positive Series Regulator

Negative Series Regulator

POSITIVE SERIES:

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7805, 7806, 7809, 7812

Here, the first two number in the IC ,i.e 78 Refers the positive series.

And the Next two Number i.e., 05,06,09,12 refers the voltage level.

NEGATIVE SERIES:

7905,7906,7909,7912.

Here, the first two number in the IC i.e,79 refers the negative series.And the next two number i.e,05,06,09,12 refers the voltage level.

Now we are using only the positive series i.e,7806 voltage regulator

IC for our power supply /charger circuit .So the input voltage is given to the first pin, the second pin is grounded

And the output is taken from the third pin.

POWER SUPPLY CIRCUIT/ CHARGER CIRCUIT :

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CELLULAR COMMUNICATION:

The cellular communication is divided into two sections. They are,

1) Transmission section

2) Receiving section

Transmission section:

Communication from mobile to tower.

During a call the voice signal is received by the MIC. The received analog

signal is converted to electrical signal by MIC. The analog signal cannot be transmitted

and so it is converted to digital signal using ADC converter. The converted digital signal

cannot be transmitted because the transmission range for digital signal is very low. In

order for transmitting the signal, a carrier signal is added with the original signal. This

process is said to be MODULATION. The modulation process is done by RF or Network

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ADC

ADC

MICV

ADC

RF

ADC

TxFilter

ADCAmplifier

PFOADC

AntennaSwitch

Antenna

ADC

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IC. The noise signal mixed with the modulated signal is filtered using transmitter filter

(Tx) and then it is amplified. The PFO (Power Filter Oscillator) selects the tower. The AS

(Antenna Switch) selects the user network and transmits the signal to antenna. The

antenna transmits the signal to the tower.

Receiving section:

Communication from tower to mobile.

The receiving section is the reverse process of transmitting section. Here,

the signal from tower is received by mobile antenna. The AS (Antenna Switch) sets the

frequency for the incoming call. The noise in the received signal is filtered by the

receiver filter (Rx Filter) and then it is amplified. The amplified signal is given to the RF/

NW IC for DE-MODULATION i.e., the carrier signal is suppressed and only the original

signal is present at the output of the RF IC. Since it is a digital signal which cannot be

heard by a person, so it is converted to an analog signal by a DAC (Digital to Analog

Converter). Then the analog signal which is in the form of electrical signal is given to the

speaker, it converts the electrical signal to the voice signal.

MOBILE COMMUNICATION

The Switching System

The Switching system is very operative system in which many crucial operations are

conducted, SS systems holds five databases with in it which performs different functions.

If we talk about major tasks of SS system it performs call processing and subscriber

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AntennaSwitch

Antenna

ADC

TOWER

DACSPKR RF IC Amplifier

Rx FilterADC


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related functions. These five databases from SS systems are HLR, MSC, VLR, AUC and

EIR. Lets study each database in detail and learn what functions this little systems

performs.

HLR-HomeLocationRegister:

HLR is database, which holds very important information of subscribers. It is mostly

known for storing and managing information of subscribers. It contains subscriber service

profile, status of activities, information about locations and permanent data of all sorts.

When new connections are purchased, these subscribers are registered in HLR of mobile

phone companies.

MSC- Mobile Services Switching Center:

MSC is also important part of SS, it handles technical end of telephony.It is build to

perform switching functionality of the entire system. Its most important task is to control

the calls to and from other telephones, which means it controls calls from same networks

and calls from other networks. Toll ticketing, common channel signaling, network

interfacing etc are other tasks which MSC is responsible for.

VLR- Visitor Location Register:

VLR performs very dynamic tasks; it is database which stores temporary data regarding

subscribers which is needed by Mobile Services Switching Center-MSC VLR is directly

connected to MSC, when subscribe moves to different MSC location, Visitor location

register VLR integrates to MSC of current location and requests the data about

subscriber or Mobile station ( MS ) from the Home Location Register HLR. When

subscriber makes a call the Visitor location register-VLR will have required information

for making call already and it will not required to connect to Home Register Location -

HRL again.

AUC- Authentication Center:

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AUC is small unit which handles the security end of the system. Its major task is to

authenticate and encrypt those parameters which verify users identification and hence

enables the confidentiality of each call made by subscriber. Authentication center AUC

makes sure mobile operators are safe from different frauds most likely to happen when

hackers are looking for even smallest loop wholes in systems.

EIR Equipment Identity Register:

EIR is another important database which holds crucial information regarding mobile

equipments. EIR helps in restricting for calls been stolen, mal functioning of any MS, or

unauthorized access. AUC Authentication center and EIR- Equipment Identity registers

are either Stand-alone nodes or some times work together as combined AUC/EIR nodes

for optimum performance.

The Base Station System (BSS)

The base station system have very important role in mobile communication. BSS are

basically out door units which consist of iron rods and are usually of high length. BSS are

responsible for connecting subscribers (MS) to mobile networks.All the communication

is made in Radio transmission.The Base station System is further divided in two systems.

These two systems, they are BSC, and BTS. Lets study these two systems in detail.

BTS The Base Transceiver Station:

Subscriber, MS (Mobile Station) or mobile phone connects to mobile network through

BTS; it handles communication using radio transmission with mobile station. As name

suggests, Base transceiver Station is the radio equipment which receive and transmit

voice data at the same time. BSC control group of BTSs.

BSC The Base Station Controller:

The Base Station normally controls many cells, it registers subscribers, responsible for

MS handovers etc. It creates physical link between subscriber (MS) and BTS , then

manage and controls functions of it. It performs the function of high quality switch by

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handover over the MS to next BSC when MS goes out of the current range of BTS, it

helps in connecting to next in range BTS to keep the connection alive within the network.

It also performs functions like cell configuration data, control radio frequency in BTS.

Data moves to MSC-Mobile switching center after BSC done processing it. MSC is

switching center which acts as bridge between different mobile networks.

WIRELESS COMMUNICATION

Wireless communication is used for data transformation with out any wire.

Infra Red

It is a wireless communication for data transfer from mobile to

mobile, which uses IR LED for transmitting and Photo diode for

receiving.

Advantage:

It is a wireless communication process.

Disadvantage:

It uses ray for data transfer, so some of the electronic components may be damaged, since

that ray is harmful for the components.Only can use for short range.

Virus may affect easily.

Infrared light lies between the visible and microwave portions of the electromagnetic

spectrum. Infrared light has a range of wavelengths, just

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like visible light has wavelengths that range from red light to violet. "Near infrared" light

is closest in wavelength to visible light and "far infrared" is closer to the microwave

region of the electromagnetic spectrum. The longer, far infrared wavelengths are about

the size of a pin head and the shorter, near infrared ones are the size of cells, or are

microscopic.

Bluetooth

The system is named after a Danish king Harald Blatand ( Harold

Bluetooth in English), King of Denmark and Norway from 935 and 936 respectively, to

940 known for his unification of previously warring tribes from Denmark, Norway and

Sweden . Bluetooth likewise was intended to unify different technologies like computers

and mobile phones. The Bluetooth logo merges the Nordic runes for H and B.

General information

A typical Bluetooth mobile phone headset

The latest version currently available to consumers is 2.0, but

few manufacturers have started shipping any products yet. AppleComputer, Inc. offered the first products supporting version 2.0

to end customers in January 2005. The core chips have been available to OEMs (from

November 2004 ), so there will be an influx of 2.0 devices in mid-2005. The previous

version, on which all earlier commercial devices are based, is called 1.2.

Bluetooth is a wireless radio standard primarily designed for low power consumption,

with a short range (up to 10 meters) and with a low-cost transceiver microchip in each

device.

It can be used to wirelessly connect peripherals

like printers or keyboards to computers

Versions:

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Bluetooth 1.1

In version 1.1 many errata found in the 1.0B specifications were fixed. There was added

support for non-encrypted channels.

Bluetooth 1.2

This version is backwards compatible with 1.1 and the major enhancements include

Adaptive Frequency Hopping (AFH) , which improves resistance to radio

interference by avoiding using crowded frequencies in the hopping sequence

Higher transmission speeds in practice

extended Synchronous Connections (eSCO) , which improves voice quality ofaudio links by allowing retransmissions of corrupted packets.

Received Signal Strength Indicator (RSSI)

Host Controller Interface (HCI) support for 3-wire UART

HCI access to timing informationfor Bluetooth applications.

Bluetooth 2.0

This version is backwards compatible with 1.x and the major enhancements include

Non-hopping narrowband channel(s) introduced. These are faster but have been

criticised as defeating a built-in security mechanism of earlier versions; however

frequency hopping is hardly a reliable security mechanism by today's standards.

Rather, Bluetooth security is based mostly on cryptography.

Broadcast/ multicast support . Non-hopping channels are used for advertising

Bluetooth service profiles offered by various devices to high volumes of

Bluetooth devices simultaneously, since there is no need to perform handshaking

with every device. (In previous versions the handshaking process takes a bit over

one second.)

Enhanced Data Rate (EDR) of 2.1 Mbit /s.

Built-in quality of service .

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Distributed media-access control protocols .

Faster response times .

Halved power consumption due to shorter duty cycles.

Advantages:

It can be used for long distance.

Data transfer rate is very faster.

Virus :

The codes which cant be read by the mobile phone is called virus.

A mobile phone virus is a computer virus specifically adapted for the cellular

environment and designed to spread from one vulnerable phone to another. Although

mobile phonevirus hoaxes have been around for years, the so-called

Cabir virus is the first verified example. The virus was created by a

group from the Czech Republic and Slovakia called 29a, who sent it

to a number of security software companies, including Symantec in

the United States and Kapersky Lab in Russia. Cabir is considered a "proof of concept"

virus, because it proves that a virus can be written for mobile phones, something that was

once doubted.

SYMPTOMS OF VIRUS INFECTION

Your phone may go into re-starting frequently.

Your phone may operate slower than usual.

Your phone may stop obeying commands or locks up

often.

You may not be able to access some applications in your

phone.

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Some applications on your phone may refuse to work properly.

Unusual error messages may occur often and menus may appear unclear.

Icons which you did not put may crop up and recently opened attachments may

have dual extensions.

Installed antivirus is likely to be disabled or the program may

not start.

New antivirus cannot be installed and even if it is installed, it

will refuse to work until the phone is debugged.

Battery depletion rate is likely to increase because the virus through its malicious

operations will over labor the battery.

These are some common signs of assault by a virus although soft or hardware problemsmay present some of these symptoms.

Mobile Locks

There are two types of locks. They are,

User Lock,

SP Lock.

User Lock is divided into two types they are Keypad lock and Phone lock.

SP lock is the service provider lock it is divided into two types they are PIN and PUK

PIN

Personal identification Number. In the context of wireless devices, the PIN is a code used

in conjunction with a SIM card to complete a call or data transmission. Used for SIM

security. Supplied by the service provider.

PUK

PIN/PIN2 Unblocking Key. Used to unblock the PIN/PIN2. Supplied by the service

provider.

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PCB DIAGRAM

Printed circuit board is the abbreviation for the PCB. There are four layer in the

PCB as shown below,

Layer 1 Antonna Switch

Layer 2

VCO Receiver

Voltage Transmitter

Contro

oscillator FLAH ICS

Layer 3

Layer 4

TROUBLE SHOOTING

Cell phone troubleshooting helps you fix your phone, and it also allows you to figure out

if you have a larger issue with your carrier. Common problems can often be fixed

yourself, or at least it will identify if a repair or replacement might be required. Read on

if you're experiencing issues with your cell phone such as your battery losing power or

the phone ceasing to work after impacting a hard surface.

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PFO IC AS

RX

PX

RFIC

POWER ICCPU

Flash IC

CHARGE

ICSIM IC

FM IC

BLUETOOTH

ICCAMERA


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Dropped Calls

1. If you are having a problem with dropped calls, see if it happens in a particular

geographic location. If so, alert your carrier so that it can begin the process of

providing better coverage in that spot. If calls are being dropped at random, it

could be because of bad weather orbuildings that are blocking your signal. If

neither of these things appears to be the issue and your phone is relatively new,

your SIM card may be malfunctioning. Take your phone to a local dealer to swap

your card.

Water Damage

2. If you've dropped your phone in water, remove the battery and leave the phone in

a cool, dry location with the battery out and the casing left open. Dab a cotton

swab into the phone to remove any excess water and leave the phone to dry. You

can also place the phone in a container of dry rice, which will absorb excess

moisture. After a day, reseat the battery and turn the phone on to see if it works

properly.

Battery Issues

3. Batteries often don't last as long as your phone. If the battery won't hold a charge

for more than an hour or two, then the cheapest fix is to buy a new battery. It's far

less expensive than buying a new phone.

Dropped Phone

4. If you've just watched your phone fly out of your hand onto the sidewalk, knowthat it's not necessarily irretrievably damaged. Simply reseating the battery and

SIM card will often have your phone working like new, minus a few dents and

nicks. If the LCD display is damaged, however, it's often cheaper to buy a new

phone than attempt to have it repaired.

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Can't Receive Calls

5. If your phone won't receive calls, check two things. First, check to see if you can

make outgoing calls. If you can, then verify whether you have a "do not disturb"

option on your phone. You can find this information in the manual that came with

the phone or online (see Resources below). If you can't make outgoing calls, then

contact your service provider. The company may have inadvertently turned your

service off. If you're behind on your payments, the carrier may have suspended

your service.

Samsung Mobile Phone Troubleshooting

Touch Screen or Main Screen Locks

1. A very common problem for many phones is when the Samsung freezes or locks

up while you are using it. There's a very simple formula that will resolve this and

helpyoutroubleshootthisproblemeverytime.

While you have the phone turned on, pull the battery out of the Samsung. Now,

wait for at least 30 seconds to allow the phone to shut down completely (it is like

a mini-computer). After 30 seconds, put the battery back into the phone and put

the battery cover on. Now, hit the power button (or the red end call key) to turn

the phone back on. Your phone should now function normally and the problem

should be resolved.

Insert SIM Card Error

2. The insert SIM card error message can appear on your phone for a number of

reasons. This can even occur on a Samsung if you have the SIM inserted in the

phone. While it can be frustrating, there are some quick fixes to this solutions.

SIM cards rely on "contacts" (metal contacts that establish a connection between

the card and the phone) to function properly. If this connection breaks or is not

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stable, it will cause an Insert SIM error. What you need to do is get to the SIM

card on your phone. This is typically underneath the battery on the device. Once

you get to the SIM card, remove it and re-insert it back into the device, making

sure it firmly locks in place. If you need specific help with this, check out your

user guide or visit Samsung support for assistance.

After you insert it properly, turn on the phone and it should be working now with

full network access.

Cannot Make or Receive Calls

3. Call functionality can experience issues for a variety of reasons, many of which

you can resolve on your own. If you cannot place a call or receive a call on your

Samsung, make sure that you have an active signal on the phone. You will also

want to avoid electrical or radio interference or obstructions, such as bridges,

parking garages or even tall buildings. Again, you will need a solid SIM card

connection and also make sure that your battery is fully charged.

Cannot Hear Callers

4. If you are getting calls on your phone and you cannot hear anyone once you

connected, first try to adjust the volume on the phone. If that does not work, make

sure that you have an active signal on the phone with good coverage. Sometimes,

a headset could cause the problem. If you use one, make sure that it is connected

properly or that you have not hit the mute button on the headset.

No Power

5. If you keep on pressing that power key on your phone but cannot get your phone

on, make sure that you have charged your battery for at least two hours. Some

Samsung phones do not turn on if their battery level is under 25 percent. While

this may be enough juice to run the phone, it cannot power it one. Another check

would be to verify that the battery is in the device securely. Make sure it has

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clicked into place and that the metal contacts on each end are not obstructed in

any way.

Basic Mobile Phone Fault Correction Procedure :

Network Problem

Antenna, Antenna Switch, PFO (RF Power Amplifier), FDK (1st OSC VCO), 13 MHz.

No Network Found

FDK, 13MHz, PFO, CPU.

No Access

Antenna, Antenna Switch, PFO

Set Dead

Battery, Voltage at the Battery

Connector should be more than the Battery ?Voltage, if no then check Power IC, CPU,

Connector.

No Display

Display Connector, Check its track for open, check display.

Gets OFF

(When the phone is switched on, it immediately switches OFF) Battery Loose, Battery

Faulty,

Check Battery Connector, Some humidity(water etc.) may have gone in the set.

Charging Problem

Check the battery voltage written on them. During charging battery contact pins should

contain more voltage then the battery voltage. If These pins contain less voltage then the

power section is faulty. Check the charger, check charger socket, PFO, Power IC, CPU

and the capacitors connected to the Flash.

Dialing problem

Check keypad and its Tracks, Dialer IC, CPU and its Tracks

Ringer Problem

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Check Ringer/Buzzer, Ringer IC (in some models Ringer IC consists of light section

also)

SIM Card Problem

Check SIM Card, SIM Card Socket, ITs Contacts, Track,

EEPROM, Flash Program. In Many handsets fault gets rectified when hot air is given to

the ICs.

Key

If no number is getting dialed then clean the keypad connector, check keypad, tracks.

LED

Check LEDs. These LEDs can be checked like other common LEDs, LED glows when

forward reading is pbtained. Replace the faulty LED. These LEDs are costly their cost

depends on their color. One LED costs around2-35 rupees.

MOBILE PARTS

Mobile parts are divided into four categories. They are as follows,

External parts,

Internal parts,

Fixed components,

Application ICs.

External parts:

The parts which can be remove by hand/soldering is called as external

parts.

Example: Panel, Display, etc,

Internal parts:

The parts which can be removed by blower is called as internal parts.

Example: RF IC,PFO IC, etc,

Fixed components:

The parts which cant be remove in the PCB is called as Fixed

components.

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Example: CPU IC, Flash IC.

Application ICs:

The ICs which are used for entertainment are called Application ICs.

Example: FM IC,B/T IC, etc,

Glossary of Terms :

Batteries

Different types of Batteries

Mobile phones currently employs three battery technologies : Nickel-Cadmium (NiCd) ,

Nickel-Metal Hydride (NiMH) and Lithium-Ion (Li-Ion). While NiCd has been the

standard rechargeable battery used in the wireless industry for years, NiMH and Li-Ion

batteries have gained popularity by improving upon some of the shortcomings of the

NiCd technology.

Nickel-Cadmium (NiCd)

High number of charge/discharge cycles.

Performs well at low temperatures.

Performs best if fully discharged periodically.

Nickel-Metal Hydride (NiMH)

30 percent more capacity over a standardNiCd.

Less prone to memory effect that occurs inNiCd.

Environmentally friendly due to fewer toxic materials used in its manufacturing.

Lithium-Ion (Li-Ion)

Lighter in weight,

Low self-discharge rates, Relatively long cycle life.

Blue Tooth

Blue Tooth is an exciting new technology that allows devices such as mobile phones, LapTop computers, digital cameras and other portable devices to communicate with each

other without using cables to connect them. Blue Tooth is a technology that allows these

devices to communicate with each other using short-range radio waves.

CDMA

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Code Division Multiple Access (CDMA) is one of several digital wireless transmission

methods in which signals are encoded using a pseudo-random sequence which

corresponds to a different communication channel that the receiver also knows and can

use to decode the received signal. CDMA is one of several spread spectrum techniques.

CDMA offers improvements over analog transmission in the areas of reduced call

dropping, battery power conservation, more secure transmission and increased service

options.

Cell

The geographic area encompassing the signal range from one base station (a site

containing a radio transmitter/receiver and network communication equipment). Wireless

transmission networks are comprised of many hexagonal, overlapping cell sites to

efficiently use radio spectrum for wireless transmissions. Also, the basis for the term

cellular phone .

Cellular

In wireless communications,cellular refers most basically to the structure of the wireless

transmission networks which are comprised of cells or transmission sites. Cellular is also

the name of the wireless telephone system originally developed by Bell Laboratories that

used low-powered analog radio equipment to transmit within Cells. The terms Cellular

is also used to refer to non-PCS products and services.

GSM

Global System for Mobile Communications or GSM is the digital transmission technique

widely adopted in Europe and supported in North America for telephone uses. GSM uses

the 1900MHz. GSM uses 900 MHz and 1800MHz in Europe.

MIN

The Mobile Identification Number (MIN) is a unique 24-bit number assigned by the

wireless service provider to each phone it sells or includes in service plans. Unlike an

Electronic Serial Number (ESN), a MIN is changeable because wireless phones may

change hands or phone owners may move to another coverage region,requiring a

different service plan.

MMM

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Mobile Media Mode (MMM) products have the ability to provide information services

such as stock quotes, flight information and reservations, news, sports, weather updates,

and even access to e-mail wirelessly. Check with your local cellular service provider to

find out when services will be available in your area.

PIN

Personal identification Number. In the context of wireless devices, the PIN is a code used

in conjunction with a SIM card to complete a call or data transmission. Used for SIM

security. Supplied by the service provider.

PIN2

Personal identification Number used for the control of Fixed Dial Memory and call

charge metering. Supplied by the service provider.

PUK/PUK2

PIN/PIN2 Unblocking Key. Used to unblock the PIN/PIN2. Supplied by the service

provider.

Roaming

Usinng a wireless phone outside of your service providers local coverage area or home

calling area is reffered to as roaming. Roaming arrangements between service providers

expand the potential area for phone use. Service providers typically charge a higher per-

minute fee for calls placed outside their home calling or coverage areas.

SIM

A Subscriber Identification Module is a Card commonly used in a GSM phone. The card

holds a microchip that stores information and encrypts voice and data transmissions,

making it close to impossible to listen in on calls. The SIM card also stores data that

identifies the caller to the network service provider.

It also stores unique subscriber and user-entered information such as Phone Book, Fixed

Dial Memory and short messages. Supplied by the service provider.

TDMA

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Time Division Multiple Access is one of several technologies used in digital wireless

transmissions that increase the efficiency of the network by allowing a greater number of

simultaneous transmissions. Networks using TDMA assign 6 timeslots for each

frequency channel. Devices using the wireless network send bursts of information that

are reassembled at the receiving end.

Third Generation

The Third Generation (3G) mobile devices and services will transform wireless

communications into on-line, real-time transfer of information, regardless of time and

place. You will be able to send electronic postcards with images, and you can even have a

live video conference using your 3G mobile communication device.

WAP

Wireless Application Protocol is a protocol developed to allow intelligent transmission of

optimized Internet content to wireless phones.

WLL (Wireless Local Loop)

Wireless service system that complete with or substitute for local wireline phone service.

TRACKING

Creating a new way in a circuit is called tracking

If we dint get continuity properly we use tracing

RESISTER TRAKING

Tracking is possible in Resistor

In a service if a single resister fault we use can track

CAPASISTER TRACKING

Tracking is possible in Capasitor when it is connected in series

DIODE

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Tracking is not possible in Diode

INDUCTOR

In Inductor tracking is most impossible

We cannot make tracking for single inductor For Additional Inductor Tracking is possible

Tracking is possible for inductor near transistor

mobile servicing

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