Handset repair Engneer

TELECOM INDUSTRY- INTRODUCTION
Telecom services have been acknowledged globally as an
essential tool for the socio-economic development of a nation.
India is currently the world’s second-largest telecommunica -
tions market and has registered exceptional growth in the past
few years.
The Indian mobile economy is growing
rapidly and will contribute
approximately US$ 400 billion to India’s
gross domestic product (GDP),
according to report prepared by GSMA
in collaboration with BCG.

MARKET SIZE
Telecommunications is one of the prime support services
needed for rapid growth and modernisation of various sectors
of the economy. The total mobile services market revenue in
India will reach US$ 29.8 billion in 2014 and is expected to touch
US$ 37 billion in 2017, registering a compound annual growth
rate (CAGR) of 5.2 per cent, according to research firm IDC.
India is projected to have 213 million mobile internet users by
June 2015, a 23 per cent rise over a six month period,
according to Mobile Internet in India 2014 report. The
broadband services user-base in India is expected to grow to
250 million connections by 2017, according to the UK-based
GSM Association (GSMA).

INVESTMENT
With daily increasing subscriber base, there have been a lot
of investments and developments in the sector.
The industry has attracted FDI worth US$ 16,994.68 million
during the period April 2000 to January 2015, according to the
data released by Department of Industrial Policy and
Promotion (DIPP).

GOVERNMENT INITIATIVES
The government has fast-tracked reforms in the telecom sector
and plans to clear the proposal allowing spectrum trading and
sharing ahead of the year-end deadline as it wants to lift the
business sentiment for the forthcoming airwave auction. Some
of the other major initiatives taken by the government are as
follows:
The Government of Uttar Pradesh (UP) has secured investment
deals valued at Rs 5,000 crore (US$ 804.64 million) for setting
up mobile manufacturing units in the state.
Citizens of India are expected to get a minimum of 2 megabits
per second (MBPS) Wi-Fi speed at every government owned
service point.

REGULATORY FRAMEWORK
The Department of Telecommunications (DoT), reporting to the
Ministry of Communications (MoC) is the key body for policy
issues and regulation, apart from being a basic service provider
to rest of country. By an act of Parliament, the Telecom
Regulatory Authority of India (TRAI) was formed to be the
regulatory agency.
Ministry of Communication:
All the operations of this sector come under the control of
MoC. It is responsible for all major policy changes, planning,
supervision, spectrum control, etc.
Department of Telecommunications:

REGULATORY FRAMEWORK
Telecom Regulatory Authority of India:
TRAI was founded to act as an independent regulatory body
supervising telecom development in India. The operations of
this sector are determined as under the Indian Telegraph Act
of 1885 – A document buried in the sands of time.
The Telecom Commission:
The Telecom Commission was set up by the government of
India vide Notification dated April 11, 1989 with
administrative and financial powers of the government of
India to deal with various aspects of Telecommunications.

TELECOMMUNICATION SERVICES
Today tariff for telecommunication services in India is one of
the lowest in the world. The Indian consumer has immensely
benefited from such lower tariffs which has also been a major
factor for explosive growth in the sector. Following is the list of
services offered by both GSM and CDMA operators:
Telephone services:
NSD/ISD services, Computerized trunk services, Pay phones,
National & international leased lines circuits, Telex, Telegraph
services (manual & automatic), X-25 based Packer Switched
Data Network (NET), Gateway Packet Switched Data Services
(GPSS), Gateway Electronic Data Interchange Service (GEDIS).

ROAD AHEAD
India will emerge as a leading player in the virtual world by
having 700 million internet users of the 4.7 billion global users
by 2025, as per a Microsoft report. With the government’s
favourable regulation policies and 4G services hitting the
market, rapid growth is expected in the Indian telecommunic-
ation sector in the next few years.
Also, with developments in this sector, services such as
security and surveillance, remote monitoring of ATM
machines, home automation, traffic management, retail,
logistics and grid energy could eventually facilitate
optimisation of resources.

ACTIVITY
Trainer will divide the class into 2-3 groups and ask the
participants to prepare presentation on TELECOM INDUSTRY,
ITS GROWTH AND CURRENT STATUS IN INDIA. Post
completion of the presentation, trainer will ask the
participants to present the work in groups in the classroom.
You are a Mobile hardware repair technician and you need
to understand the handset repair including hardware and
software components and testing the handset for adequacy
post repair.. Prepare a survey form with key questions and
collect the feedback from at least 10 customers. They may
be from your own training center or the peer.

SAFETY PRECAUTIONS - PPP
Wear a Ground Strap
Anti static wrist strap is used to avoid risk of electrostatic
discharge from a human body to an electronic
component circuit.
Hand Gloves:
It also protect the cell phones
from scratches and possible
electrostatic discharge. A cotton
cloth made glove is essential to
use.

SAFETY HANDLING WITH REWORK AND
SOLDERING STATIONS
Rework and soldering Station is a hot surface device and can
cause fire instantly and extreme burns on skin when
improperly handled.
Always observe and Set it in proper heat and air flow amounts.
Secure a safe place on your
table where the rework
station is located. Avoid in
placing it that people may
pass or standing by especially
kids.

SAFETY HANDLING OF A MULTITESTER
A multi tester may damaged easily when improperly handled.
Always check ranges when checking voltages and currents. The
deplection yoke of the analog meter may be bust out when
overdrive by a current to it.

MEASURING RESISTANCE
Careful inspection of the dial should reveal the OHM scale. It is
usually the top-most scale and has values that are highest on
the left of the dial (a sideways "8" for infinity) and gradually
reduce to 0 on the right. This is opposite of the other scales;
they have the lowest values on the left and increase going
right.
Set the multimeter to Ohms or Resistance (turn meter on if it
has a separate power switch). Understand that resistance and
continuity are opposites. The multimeter measures resistance
in ohms, it cannot measure continuity. When there is little
resistance there is a great deal of continuity.

MESURING VOLTAGE AC-DC
Set the meter for the highest range provided for AC or DC
Volts. Many times, the voltage to be measured has a value
that is unknown.
For this reason, the highest range possible is selected so that
the meter circuitry and movement will not be damaged by
voltage greater than expected.

Set the meter to the highest AC or DC Amp range supported. If
the circuit to be tested is AC but the meter will only measure
DC amps (or vice-versa), stop. The meter must be able to
measure the same mode (AC or DC) Amps as the voltage in the
circuit, otherwise it will indicate 0.
MEASURING CURRENT BY AMPERE

SAFETY HANDLING OF A POWER
SUPPLY
Power supply may also damage and cause damaged to a
component.
Always set it and determine the correct amount of
Voltage range to avoid risk of blowing out any electronic
parts.
Do not short the two alligator
clips because the power supply
will heat up and may busted
out the protection fuse.

FIRST AID TREATMENT OF
ELECTROCUTED PERSON
Electric shock accidents are caused by an electric current
from a electrical source passing through the body. The effects
from a shock can be anything from a tingling to instant death.
Do not endanger yourself
If the victim is still in contact with the electrical current, you
must be careful to avoid being shocked yourself.
Break the current.
Shut off the current at the power box. If no shut off is
immediately available, use a non-conducting item to move the
victim, such as a wooden broomstick, blanket, or rope.
Call for emergency assistance:
Make certain to state that the victim is suffering from shock.

FIRST AID TREATMENT OF
ELECTROCUTED PERSON
If the victim is unconscious:
check to see if they are breathing and have a pulse. Electric
shocks may knock the person unconscious, halt their
breathing, and stop the heart.
If the victim is not breathing, begin rescue breathing. If it is
needed, begin CPR.
Do not attempt to move the victim
Cover the victim in a blanket and stay
with them until help arrives.
Give CPR if you know the process until
help arrives.

USE OF FIRE EXTINGUISHERS
Portable Fire Extinguishers can save lives and property by
putting out or containing fires within the capability of the
extinguisher. However, they must be of the correct type for
the particular fire, and they must be used correctly.

HOW TO USE ELECTRICAL FIRE
EXTINGUISHERS?
The classes of fire
Class A - Ordinary Combustibles , Class B - Flammable and
combustible liquids , Class C - Flammable gases, Class D -
Combustible metals, Class E - Electrically energised
equipment, Class F - Cooking oils and fats.

HOW TO USE ELECTRICAL FIRE
EXTINGUISHERS?
Electrical fires must be expelled using nothing more than
electrical fire extinguishers. Clean and non conductive
agents like carbon dioxide, baking soda, dry chemical
powder, and Purple-K powder (PKP) are contained in these
expellants.

GROUP ACTIVITY
GROUP ACTIVITY – 01: PRESENTATION
CREATE A GROUP PREPARE A PRESENTATION ON SAFETY PRECAUTIONS
USES OF SAFETY TOOLS.
GROUP ACTIVITY – 02: SURVEY
YOU ARE A MOBILE HANDSET REPARE TECHNICIAN AND YOU NEED TO
UNDERSTAND THE SAFETY RULES FOR REPARING OF MOBILE HANDSET.
PREPARE WITH KEY QUESTIONS AND COLLECT THE FEEDBACK FROM AT
LEAST 10 CUSTOMERS ABOUT THE SAFETY PRECUATIONS. THEY MAY BE
FROM YOUR OWN TRAINING CENTER OR THE PEER.

BASIC ELECTRONICS- DEFINITION OF
ELECTRONICS
Electronics is the branch of science that deals with the study
of flow and control of electrons (electricity) and the study of
their behaviour and effects in vacuums, gases, and
semiconductors, and with devices using such electrons.
This control of electrons is
accomplished by devices that resist,
carry, select, steer, switch, store,
manipulate, and exploit the electron.

OHM'S LAW
What is Ohm's Law?
Ohm's Law is made from 3 mathematical equations that
shows the relationship between electric voltage, current
and resistance.
What is voltage? An analogy . The difference between
the pressure of water in the tank and the water that
comes out of a pipe connected at the bottom leading
to a faucet is determined by the size of the pipe and
the size of the outlet of the faucet. This difference of
pressure between the two can be thought of as
potential Voltage.

OHM'S LAW
What is current?
The term current refers to the quantity, volume or
intensity of electrical flow, as opposed to voltage, which
refers to the force or "pressure" causing the current flow.
What is resistance? An analogy would be the size of the
water pipes and the size of the faucet.
Ohm's Law was named after Bavarian mathematician
and physicist Georg Ohm.
Ohm's Law can be stated as mathematical equations,
all derived from the same principle.
V = I x R (Voltage = Current multiplied by Resistance)

SERIES CIRCUIT
A circuit composed solely of components connected in series is
known as a series circuit. A Simple Series Circuit: Let's start
with a series circuit consisting of three resistors and a single
battery:

PARALLEL CIRCUIT
One connected completely in parallel is known as a parallel
circuit.
Simple Parallel Circuit
The first principle to understand about
parallel circuits is that the voltage is
equal across all components in the
circuit. This is because there are only
two sets of electrically common points
in a parallel circuit, and voltage
measured between sets of common
points must always be the same at any
given time.

IDENTIFYING ELECTRONICS
COMPONENT'S CIRCUIT SYMBOLS AND
FUNCTIONS
Identifying Electronic Component and Symbol is very
important rule when fixing mobile phones problems.
Circuit Symbols
Circuit symbols are used in circuit diagrams which show
how a circuit is connected together. The actual layout of
the components is usually quite different from the circuit
diagram. To build a circuit you need a different diagram
showing the layout of the parts on strip board or printed
circuit board. Circuit symbols are used in circuit diagrams,
which show how a circuit is connected together.

CIRCUIT SYMBOLS AND FUNCTIONS
SMT Resistor
In Mobile Phones Surface Mount Moulded (SMD)
Resistor where not printed with numerical value and it is left
blank, the problem is that it is too tiny or small to print at.
In Schematic Diagram Its Original value where indicated:
For Example:
Resistances less than 1000 ohms or 1K with ''R'' indicated in
the middle indicates a decimal point like:
4R7 = 4.7Ω , 2R2 = 2.2Ω
and the rest just like how it does indicated like:
100Ω = 100 ohms, 220Ω = 200 ohms and up 4.7K = 4.7 kilo
ohms

The Printed SMD Resistor
Zero ohm resistors Surface mounted resistors are printed
with numerical values in a code related to that used on axial
resistors.
Standard-tolerance Surface
Mount Technology (SMT) resistors are
marked with a three-digit code, in
which the first two digits are the first
two significant digits of the value and
the third digit is the power of ten (the
number of zeroes).

SMT TRANSISTOR
A transistor is a semiconductor device used to amplify and
switch electronic signals. It is made of a solid piece of
semiconductor material, with at least three terminals for
connection to an external circuit.
The transistor is the
fundamental building block of
modern electronic devices, and
its presence is ubiquitous in
modern electronic systems.

DIODES - SURFACE MOUNTED
In electronics, a diode is a two-terminal electronic
component that conducts electric current in only one
direction. The term usually refers to a semiconductor diode.
The most common function of a diode is
to allow an electric current in one
direction (called the diode's forward
direction) while blocking current in the
opposite direction (the reverse
direction).
Diodes were the first semiconductor
electronic devices.

Zener diodes : Diodes that can be made to conduct
backwards. This effect, called Zener breakdown, occurs at a
precisely defined voltage, allowing the diode to be used as a
precision voltage reference..
Photodiodes : Photodiodes are
intended to sense light
(photodetector), so they are
packaged in materials that allow light
to pass, and are usually PIN (the kind
of diode most sensitive to light). A
photodiode can be used in solar
cells, in photometry, or in optical.

FUSE - SURFACE MOUNTED: In electronics and electrical
engineering a fuse (from the Latin "fusus" meaning to melt) is a
type of sacrificial overcurrent protection device. Its essential
component is a metal wire or strip that melts when too much
current flows, which interrupts the circuit in which it is
connected.
SMT INDUCTORS : An inductor or a reactor is a
passive electrical component that can store energy in a
magnetic field created by the electric current passing through
it Typically an inductor is a conducting wire shaped as a coil,
the loops helping to create a strong magnetic field inside the
coil due to Faraday's Law of Induction.

OSCILLATORS : An electronic oscillator is an electronic
circuit that produces a repetitive electronic signal, often a sine
wave or a square wave.
A low-frequency oscillator (LFO) is an electronic oscillator that
generates an AC waveform at a frequency below ≈20 Hz.
Crystal oscillator : A crystal oscillator
is an electronic circuit that uses the
mechanical resonance of a vibrating
crystal of piezoelectric material to
create an electrical signal with a very
precise frequency.

Voltage-controlled oscillator
A voltage-controlled oscillator or VCO is an electronic oscillator
designed to be controlled in oscillation frequency by a voltage
input.
The frequency of oscillation is varied by
the applied DC voltage, while modulating
signals may also be fed into the VCO to
cause frequency modulation (FM) or
phase modulation (PM); a VCO with
digital pulse output may similarly have its
repetition rate (FSK, PSK) or pulse width
modulated (PWM).

RF AND IF AMPLIFIERS AND FILTERS:
Electronic filters are electronic circuits which perform signal
processing functions, specifically to remove unwanted
frequency components from the signal, to enhance wanted
ones, or both. Electronic filters can be:
Radio frequency (RF) and
microwave filters represent a
class of electronic filter, designed
to operate on signals in the
megahertz to gigahertz
frequency ranges (medium
frequency to extremely high
frequency).

GROUP ATIVITY
QUESTIONS ONLY
Duration: 10-15 minutes
What You’ll Need: A timer
LEARNING OUTCOME: QUESTIONING
Explain Ohms Law?
Define what do you understand about Electronics?
What is Series Circuit?
Expalin with the help of digram aboy Parallel Circuit?
What are the functios of SMT resistor?
What is the function of SMT transistor?
What is an oscillator? How does it works?

HANDSET TECHNOLOGY- INTRODUCTION
Wireless phones which receive their signals from towers. A cell
is typically the area (several miles) around a tower in which a
signal can be received. Cell phones provide an incredible array
of functions.
All cell phones have special codes associated with them. The
various Cell Phone Codes used are as follows:
Electronic Serial Number (ESN)
Mobile Identification Number (MIN)
System Identification Code (SID)

HANDSET TECHNOLOGY- INTRODUCTION
Some of the necessary terminologies for cell-phone
connection are described:
Mobile Telephone Switching Office (MTSO) : The switching
office that all base station cell sites connect to.
Public Switched Telephone Network (PSTN) : It is the network
of the world's public circuit-switched telephone networks.

ANALOG CELL-PHONES (FIRST
GENERATION)
In 1983, the analog cell-phone standard called AMPS (Advanced
Mobile Phone System) was approved by the FCC and first used
in Chicago. AMPS uses a range of frequencies between 824
megahertz (MHz) and 894 MHz for analog cell phones.
A version of AMPS known as Narrowband Advanced Mobile
Phone Service (NAMPS) incorporates some digital technology to
allow the system to carry about three times as many calls as the
original version.

DIGITAL CELL-PHONES (SECOND
GENERATION)
They use the same radio technology as analog phones, but they
use it in a different way. Analog systems do not fully utilize the
signal between the phone and the cellular network -- analog
signals cannot be compressed and manipulated as easily as a
true digital signal.
Many digital cellular systems rely on frequency-shift keying
(FSK) to send data back and forth over AMPS. FSK uses two
frequencies, one for 1s and the other for 0s, alternating
rapidly between the two to send digital information between
the cell tower and the phone.

INSIDE A CELL-PHONE
A basic digital cell phone contains just a few individual parts:
A circuit board containing the brains of the phone.
An antenna, An Liquid Crystal Display (LCD) screen, A keyboard,
A microphone, A speaker, A battery.
The circuit board is the heart of the system and contains several
chips. The analog-to-digital and digital-to-analog conversion
chips translate the outgoing audio signal from analog to digital
and the incoming signal from digital back to analog. The digital
signal processor (DSP) is a highly customized processor
designed to perform signal-manipulation calculations at high
speed.

CELL-PHONE TOWER
A cell-phone tower is typically a steel pole or lattice structure
that rises hundreds of feet into the air. The box houses the
radio transmitters and receivers that let the tower
communicate with the phones.
The radios transmitters and receivers connect with the
antennae on the tower through a set of thick cables. The tower
and all of the cables and equipment at the base of the tower
are heavily grounded.

HOW VIBRATOR WORKS IN CELLPHONE
If you have a cell phone or a pager, then you know that having
it ring in the middle of a movie or performance is enough to get
you killed in some cities.
Vibrating devices that quietly
replace the ringer are therefore life-
saving devices that are an important
part of urban survival!
Figure below shows the inside of a
small toy which vibrates heavily
similar to a cell phone device.

COMMUNICATION TECHNOLOGIES IN
SECOND GENERATION CELL-PHONES
There are four common technologies used by 2G cell-phone
networks for transmitting information:
1. Frequency Division Multiple Access (FDMA) : FDMA
separates the spectrum into distinct voice channels by splitting
it into uniform chunks of bandwidth.
2. Time Division Multiple Access
(TDMA) : TDMA is the access method
used by the Electronics Industry
Alliance and the Telecommunications
Industry Association for Interim
Standard 54 (IS-54) and Interim
Standard 136 (IS-136).

SECOND GENERATION CELL-PHONES
3. Code Division Multiple Access (CDMA) : CDMA takes an
entirely different approach from TDMA. CDMA, after digitizing
data, spreads it out over the entire available bandwidth.
4. Global System for Mobile Communication (GSM) : GSM
implements TDMA in a somewhat different and incompatible
way from IS-136. GSM systems use encryption to make phone
calls more secure.

MULTI-BAND VS. MULTI-MODE CELL-
PHONES
Multiple band - A phone that has multiple-band capability can
switch frequencies. For example, a dual-band TDMA phone
could use TDMA services in either an 800-MHz or a 1900-MHz
system. A quad-band GSM phone could use GSM service in the
850-MHz, 900-MHz, 1800-MHz or 1900-MHz band.
Multiple mode - In cell phones, "mode" refers to the type of
transmission technology used. So, a phone that supported
AMPS and TDMA could switch back and forth as needed.
Multiple band/Multiple mode - It allows you to switch
between frequency bands and transmission modes as needed.

THIRD GENERATION CELL-PHONES
G technology is intended for the true multimedia cell phone --
typically called smartphones. 3G comprises several cellular
access technologies as follows:
CDMA2000 : based on 2-G Code Division Multiple Access.
Wideband Code Division Multiple Access-UMTS (WCDMA-
UMTS).
Time Division Synchronous Code Division Multiple Access
(TD-SCDMA):TD-SCDMA uses the Time Division Duplex (TDD)
mode, which transmits uplink traffic (traffic from the mobile
terminal to the base station) and downlink traffic (traffic from
the base station to the terminal) in the same frame in different
time slots.

PROBLEMS WITH CELL-PHONES
Generally, non-repairable internal corrosion of parts results if
you get the phone wet or use wet hands to push the buttons.
Extreme heat in a car can damage the battery or the cell-
phone electronics. Extreme cold may cause a momentary loss
of the screen display.
Analog cell phones suffer from a problem known as "cloning."
A phone is "cloned" when someone steals its ID numbers and
is able to make fraudulent calls on the owner's account.

PROBLEMS WITH CELL-PHONES
ELECTROMAGNETIC INTERFERENCE : Most of us experience
electromagnetic interference on a fairly regular basis.
CELL PHONE JAMMERS; A jamming device transmits on the
same radio frequencies as the cell phone, disrupting the
communication between the phone and the cell-phone base
station in the tower. It's a called a denial-of-service attack.

CELL-PHONE RADIATIONS
When talking on a cell phone, a transmitter takes the
sound of your voice and encodes it onto a continuous sine
wave. A sine wave is just a type of continuously varying
wave that radiates out from the antenna and fluctuates
evenly through space.
There are two types of electromagnetic radiation:
Ionizing radiation - This type of radiation contains enough
electromagnetic energy to strip atoms and molecules from
the tissue and alter chemical reactions in the body.
Non-ionizing radiation - Non-ionizing radiation is typically
safe.

CELL-PHONE VIRUSES
A cell-phone virus is basically the same thing as a
computer virus -- an unwanted executable file that
"infects" a device and then copies itself to other devices.
These viruses spread primarily in three ways:
Internet downloads - The virus spreads the same way a
traditional computer virus does.
Bluetooth wireless connection - The virus spreads
between phones by way of their Bluetooth connection.
Multimedia Messaging Service - The virus is an
attachment to an MMS text message.

ACTIVITY
VISIT NEARBY MOBILE REPAIRING CENTER AND COLLECT
IMAGES OF VARIOUS REPAIRING TOOLS. PREPARE A
COLLAGE AND ALSO EXPLAIN THE BENEFITS AND USES OF
EACH TOOL IN DISPLAY METHODS.
PREPARE A SAMPLE TOOL KIT.

HANDSET COMPONENTS & REPAIRING
TOOLS- CARD LEVEL PARTS
Handset components
Working with various handset repairing tools

HANDSET COMPONENTS & REPAIRING
TOOLS- CARD LEVEL PARTS

TEST EQUIPMENT
Electronic test equipment is specialized equipment which is
used in the testing of electronics. It can be utilized in the
construction of prototypes and new products, and in
maintenance and troubleshooting.
All of the devices in the family of electronic test equipment
are capable of providing some sort of information about an
electronic device or circuit.
Electricians, phone repair men, and cable installers typically
carry test gear for use in their work, and electronic test
equipment is also used by engineers, physicists, and
numerous other researchers and inventors.

SOLDERING AND DESOLDERING TOOLS
Soldering Iron
A soldering iron is a tool normally used for applying heat to two
or more adjoining metal parts such that solder may melt and
flow between those parts, binding them securely, conductively
and hermetically.

Soldering LEAD: Soldering lead is used to bond or connect
electronic components.
Soldering Paste: Solder paste (or solder cream) is used for
connecting the terminations of integrated chip packages with
land patterns on the printed circuit board.

Soldering Wick
A solder wick (also desoldering wick
or desoldering braid) is a tool for
removing solder from any solder joint.
Close up to a piece of solder wick
To remove solder with it, one presses
the wick onto the solder joint to be
removed and then heats the wick
portion that is on the connection with
the tip of a soldering iron.

MUITIMETER TESTER
What is a multimeter tester?
A multitester or multimeter is a device which can be used to
gather data about electronics circuits. A basic multitester can
measure resistance, voltage,current and continuity, while more
advanced versions may be able to provide additional data.
Analog Multitester: Basic
Multitester has features like as
follows: Resistance Set Value: x1,
x10, = multiply by 10. x1K= it
means multiply it by 1000
x10K = it means multiply it by
10,000.

MUITIMETER TESTER
Digital Multitester
A digital multimeter is a tool that
can measure amps, volts, and
ohms. It is different from an
analog meter, which has a
needle and a gauge, in that it
has a digital light-emitting diode
(LED) display. Digital multimeters
are typically more accurate than
their old analog counterparts.

SMD REWORK STATIONS
SMD (Surface Mounted) Rework station is used to remove,
replace, do re-balling BGA (Ball Grid Alley) chips and SMD
components. It is made of high quality heating material. De
soldering and soldering of BGA's are precisely controlled.

SMD REWORK STATIONS
Infrared or IR SMD Rework Station
The small amount of Infrared light is amplified to produce a
very high temperature Lazer Beam. It is digitally designed
and can be set automatically.
A set example of an IR SMD rework Station. Note: the
Author is not endorsing any product.

ADJUSTABLE DC POWER SUPPLY
Adjustable DC Powers Supply
The Dc power Supply can be used to substitute for the Battery
Voltage when do live voltage checking on the PCB circuits...
This is being used to trace the power supply line in electronic
circuit. Here's a sample of substituting DC voltage in working
cell phone repair tracing B+ line.

CLEANING TOOLS
Cleaning kits and tools is also
necessary when repairing specially
when working wet units, corroded
or rusted PCP boards. Some
cleaning tools may found at
household or home products and
not so hard to find and prepare it.

CLEANING TOOLS
A cotton cloth or sponge and
cotton buds which help to wipe
extra solvents, dust,rust and dirt.
Anti Static Spray or liquids used to
eliminate water residues and
corrosive element in PCB
component.

CLEANING TOOLS
A lacquer thinner is a substitute to
anti static cleaner and commonly
and widely used by many
technician's.
An Ultrasonic Cleaner- A machine
that cleans by using a fluid that is
vibrated at 20,000 cycles per
second.

REBALLING KITS
Re-balling kits are used to repair
broken or weak soldered BGA
(Ball Grid Array) Chips. This is
very important tools when it
comes to hardware problem
troubleshooting in various
mobile phones.
These are the kits you must
prepare to be able to proceed in
reballing BGA chips.

REBALLING KITS
A Solder Balls : Solder balls have
different sizes and measured by
diameter, that match on every chips
bumps sizes also. These are the
common Soldering Ball diameter
ranges for mobile phones chips.
This is being used to properly align
the solder ball on every bumps of
the chips.
Spatula : This is used to gathered
the solder ball on each holes of the
Stencil plates.

REBALLING KITS
A liquid Flux
A PCB Board Holder : A PCB holder
is being used to maintain the
accuracy while working soldering
and to avoid gripping and
misalignment of solder balls.
A Cleaning liquid : Too many
cleaning product offered today that
is non flammable. A lacquer thinner
will work, and still widely used for
many mobile phone technicians.

WORKING TABLE EQUIPMENTS
Additional working table equipment such PC or laptop, table
lamp or a magnifying lamp, are very useful and important for
cell phone repair...
A table lamp is also require on a
working table, it adds visibility
when fixing things on a table like
cell phone .
A magnifying lamp is much better
for repairing tiny parts on a cell
phone specially when it comes
working on soldering a
component.

WORKING TABLE EQUIPMENTS
A microscope is used by many experts in finding problems such
as cracks, breakage and damaged PCB's (printed circuit board)
which is invisible to human eyesight.
You can still do repair such as, LCD
replacements and other problems
that this devices is not necessarily
to apply.

HOW TO USE AND READ A MULTIMETER
PARTS OF A MULTIMETER
Every multimeter have its own user manual. Multimeter is is
used to measure voltages AC or DC, currents and resistance,
continuity and electronics components.
1.) Indicator Zero Connector
2.) Indicator Pointer
3.) Indicator Scale
4.) Continuity Indicating LED (
CONTINUITY )
5.) Range Selector Switch knob
6.) 0-ohms adjusting knob/0- centering
meter (NULL meter) adjusting knob
7.) Measuring Terminal +
8.) Measuring Terminal - COM
9.) Series Terminal Capacitor OUTPUT
10.) Panel
11.) Rear Case

HOW TO USE AND READ A MULTIMETER
EXPLANATION ABOUT THE SCALE
1.) Resistance (OHMS) scale
2.) DCV, A scale and ACV scale (10V or
more)
3.) 0-centerig (NULL) +/- DCV scale
4.) ACV 2.5 (AC 2.5V) exclusive scale
5.) Transistor DC amplification factor
(hFE) scale
6.) 1.5 battery test (BATT 1.5V)
7.) OHMS range terminal to terminal
current (Li) scale)
8.) OHMS range terminal to terminal
voltage (LV) scale
9.) Decibel (dB) scale
10.) Continuity Indicating LED
11.0 Mirror: To obtain most accurate
readings, the mirror is devised to
make operator eyes, the indicator
pointer, and the indicator pointer
reflexed to the mirror put together in
line.

ACTIVITY
• Prepare a chart of various types of repairing tool kit and working
table equipment.
• make a chart of CARD LEVEL Parts.
• Make a chart of parts of a multimeter and
Explain each part.

Fixing hardware problems is not been easy and takes a lot of
time to consume rather than software problems, it is because
when it comes to software handling you don't really need to
open or dismantle a mobile phone handset, because only few
of them really need to.
First step in handling troubleshooting procedure:
Visualization Checkup
Know the Phones Status
Do Software Check up
Analyze The Circuit
HANDSET TROUBLESHOOTING- THE
FIRST STEP

Do the basic procedures
mentioned above, assuming that
you are familiar with the
Mouthpiece or microphone circuit,
and already know how to check a
microphone or mouthpiece
component.
you can now do this step below;
Find any available schematic
diagram and locate the
microphone circuit layout on it.
THE FIRST STEP

Use a multi-tester and check the
pads for a short circuit
Trace the line paths between the
first or the closest component
connected to each terminal pads.
Trace the line paths between the
first or the closest component
connected to each terminal pads.
THE FIRST STEP

Now the next step is to leave
behind the line paths between the
coil to the EMI-Filter for it is
uncheckable beyond that paths for
the EMI- filter is an IC.
Now check the remaining open
path which is the Resistor, you
can't check the line paths on those
area for it ends up connected to
Retu IC.
THE FIRST STEP

If all those mentioned lines above
is all in good condition you may
now proceed to suspect the EMI-
Fiter is having a problem or faulty.
You may now can check the IC
itself by analyzing the internal
circuitry inside it.
this step is most complicated job
to do with, especially for
beginners. This is one of advance
trouble shooters skills
THE FIRST STEP

Basic electronic components such
as resistors, capacitors, diodes and
transistors are widely used in any
electronic devices and gadgets.
Below are some basic D.I.Y.
regarding proper testing of this
components using a multi meter.
How to Check Resistors?
A resistor is good if its resistance is
close to the indicated value.
Tolerance should be considered
with the ohmmeter reading.
HOW TO CHECK BASIC ELECTRONIC
COMPONENTS

How to Check Capacitors?
A capacitor fails due to the
deterioration of the dielectric
material between its plate.
To test a capacitor, set the multi
meter to Rx10 or Rx1K scale.
Connect the tester negative probe
to the capacitor positive terminal
and the positive probe to the
negative terminal.
COMPONENTS

How to Check Diodes?
Connect the positive probe to the
anode and the negative probe to
the cathode. Then connect the
positive probe to the cathode and
the negative probe to the anode of
the diode. A good indication in the
first procedure will show the meter
deflected very little or may not
deflect at all.
COMPONENTS

How to determine if it is NPN or PNP transistor?
To determine the correct terminal of the transistors, set the
range selector to x 1 or 10 ohm. Connect the positive probe to
the emitter and the negative probe to the base of the
transistor.
COMPONENTS
How to Check Transistors:
Bipolar transistors are usually checked out of a circuit by means
of an ohmmeter. When it is desired to check for the resistance
across the transistor emitter and collector, NPN or PNP,
ohmmeter probes may be connected either way. A good
transistor will show above a reading above 1000 ohm.

COMPONENTS
Base your conclusion on the table:
POSITIVE PROBE TO: -----NEGATIVE PROBE TO: -----RESISTANCE
READING-- CONCLUSION:
Emitter------- -- Base---------- Less than 150 ohm ------
Transistor is NPN
Base --------------Emitter --------Infinity ----------------Transistor is
NPN

COMPONENTS
How to Check an LED
(Light Emitting Diode)
Set the Muti-meter to x1
connect the positive probe
to cathode and the
negative probe to anode.
The good and working LED
will then light up or glow, a
busted LED will not.
How to Check a Coil?
Set the multimeter to X1 a
good and working coil have a
reading approximately point to
zero ohms, without any reading
means the coil is open or
busted.

COMPONENTS
How to Check a Fuse?
A blown SMD Fuse is not visible to our naked
eye, just set the multi-meter to x1 and put
both test probe to both end side of the fuse. A
full reading here to zero or continuity check is
full. without any reading means the fuse is
already busted.
How to Check IC chips (Integrated Circuits)?
IC Chips is hard to determine faulty by using
only a multi-meter, some advance equipment
like the one that the manufacturer used during
their productions.

HOW TO TEST OR CHECK LCD OF A
CELL PHONE
It is not difficult to check LCD (Display) of a cell phone or a
tablet. LCDs being delicate tend to crack, leave blots or simply
sop working.
You can check LCD of a cell phone by any of the below methods
LCD Testers: There are testing machines available in the market
for checking of LCDs.
Check it in same model cell phone.
Check with a new LCD: Replace your LCD with a new one. If
graphics appear on the LCD, that will mean your old LCD is faulty.

HOW TO CHECK BATTERY OF A CELL
PHONE WITH MULTIMETER
Its easy to test or check the battery with the help of the
multimeter. It’s the voltage of the battery that is checked to
know how much charged it is. The unit of voltage is Volts and its
symbol is V.
Steps to check the battery with the multimeter
Switch off your cell phone and carefully remove the battery.
Now search on the label of the battery for its given voltage.
Most batteries of cell phones, digital cameras and tablets are
of either 3.7V or 3.8V

HOW TO CHECK A RINGER (LOUD
SPEAKER) IN CELL PHONES
A ringer, also called a loud speaker is a speaker through which
you hear ringtone and music. During a call, when you activate
the loud speaker, the louder voice which you start hearing also
comes from the ringer.
If the ringer becomes faulty, you
will not be able to below 3
sounds:
Ringtone
Music
Loud speaker’s voice during a
call

HOW TO CHECK A MIC IN CELL PHONES
A mic converts voice into electrical signal. It is also called
microphone and mouthpiece.
You can check it with either a digital or an analog multimeter,
but most technicians today prefer digital multi meters as analog
ones are outdated.

The speaker converts electrical
signal into voice. It is also called an
earpiece. It will always be on the
top, inside a cell phone. If it
becomes faulty, you will not be able
to hear the voice of the calling
person during a call.
You can check it with either a digital
or an analog multimeter, but most
technicians today use digital multi
meters as analog ones are outdated.
HOW TO CHECK A SPEAKER IN CELL
PHONES

Circuit-tracing’ or ‘Line-checking’ is a term used by mobile
phone repair technicians to check broken tracks on the green
coloured PCB (Printed Circuit Board). Most of these
motherboards have 7-10 layers which have tracks/lines going
from one end to another for supply of voltage and signals.
HOW TO CHECK TRACKS ON A PCB FOR
MOBILE PHONE REPAIRS
What problem comes when tracks are broken?
They are made to supply voltage to various electronic
components like mic, speaker, ringer, vibrator, LCD, etc. So if the
line for supply to a particular part is broken, the corresponding
part will fail to work.

HOW TO MAKE JUMPERS IN MOBILE
PHONES REPAIRS
Soldering a jumper wire becomes necessary for repairing any
problem in mobile phone while repairing it when a track is
broken.
How To Check Whether The Track Is Broken And We Need To
Make Jumper: In old models of cell phones, the tracks were
visible on the PCB and hence you could easily check them
through continuity with a multimeter. But now as the tracks are
marked so as to not increase the size of the PCB, we will have to
search the tracks through either jumper diagrams.

DIFFERENCE BETWEEN SOFT RESET
AND HARD RESET IN CELL PHONES
The most common software
problems are as follows:
• Freezing or becoming
unresponsive
• Getting stuck on logo while
booting
• Slow processing
• Blank screen without
booting
• Switching off automatically
• Improper functioning of
apps
Soft-Reset:
Rebooting or restarting your
cell phone is called soft-reset.
Hard-Reset:
Hard-rest (also known as
factory-reset) means deleting
all the user data in your
handset.

WHAT ARE THE DIFFERENT TYPES OF
LOCKS IN MOBILE PHONES
Normally there are two types of locks which we have detailed to
you as below: 1. Security Lock: Though this type of lock is already
present in your phone, it has to be activated if you wish to keep
your phone as well as the information and data secured.
2. SIM Lock:
This lock is also called as ‘service
provider lock’ and ‘network lock’.
Activation of the SIM lock ensures
that the phone accepts only one
SIM card. No other SIM is
accepted by the handset.

HOW TO BACKUP AND RESTORE AN
ANDROID PHONE
The importance of backing up data of your android smartphone will
be realized only when you lose your data or the phone itself.
The data most crucial for taking a backup is
Contacts, Messages, Pictures, Videos
Apps data and much more!
Backup And Restore Methods For Android
Phones
Google Sync: This is one of the best methods for
backing up data on your Android.
Backup & Reset Option: Alternatively you can
go to the backup and reset option in the
settings menu.

WHAT IS THE DEFAULT SECURITY CODE
OF ALL MOBILE PHONES
A security code is provided by the handset manufacturer for
the security of your mobile phone. The security code will
always remain the default until you change or edit it.
Below Is the list of default security
codes of major brands of cell phones:
Samsung: 0000 (4 times zero) / 00 00 00
(6 times zero) / 00 00 00 00 (8 times zero)
Nokia: 12345, All other brands of cell
phones ( Sony, Motorola, LG, Panasonic,
etc): 0000 / 1234 / 9999, Chinese
brands: 1122 / 0000 / 1234, Lava: 4321

HOW TO MAKE YOUR SMARTPHONE
BATTERY CHARGE LAST LONGER
The most common things
that drain your battery fast
are:
• Use of online apps
• Weak network signals
especially while roaming
around countryside.
• Display brightness
• Wi-fi when not used or
needed
• Background apps which are
not needed.
• Internet surfing.
• Its is necessary to understand
the above reasons and
minimize the wastage of
charge unnecessarily.

HOW TO MAKE YOUR SMARTPHONE
BATTERY CHARGE LAST LONGER
Tips to save battery charge and make it last longer:
Reduce display brightness: Turning down the brightness is up till
now the most effective way to save your battery life.
Turn off auto sync: Auto sync is the essential feature of modern
smart phones, and it drains your battery quickly too.
Turn of unnecessary features: Turn off Bluetooth, WiFi and GPS
until you need to use them.
Turn off your cell phone when not needed: It will reserve some
battery power for you, but if you have emergency calls to attend,
this might not be applicable.
Remove or uninstall apps that are not needed: This is especially
important in case of apps which always run in the background.

HOW TO INCREASE THE LIFE OF YOUR
CELL PHONE BATTERY
As we all know that a battery is the heart of an electronic gadget.
Mentioned below are some Do’s and Don’ts for prolonging the
life of your mobile phone battery.
Do not charge your battery often
Charge it before it gets drained completely
Do not directly plug in your handset into a car charger
Close unwanted services
Do turn off your handset when not in use
Note: Other than all the tips mentioned above, all those apps and
services, specially the online ones consume power, so it is
recommended to close them when not needed.

HOW TO FORMAT A CELL PHONE TO
REMOVE VIRUS
The method to format a cell phone is given below:
Open the menu and select settings. You will find an option for
reset settings in this menu. Select this. In this you will get
multiple options viz. 1. reset settings only and 2. Reset all /
master reset / erase all data. Select the second one. You will be
asked for the security code, If you have changed the default
code then type the changed code if not then enter the default
security code . If you do not know the default code then click
on default security codes for all phones and get the code for
your brand of mobile from there and type in. Your phone will be
formatted.

HOW TO FIND YOUR LOST CELL PHONE
Our cell phone today is one of our favorite, most important and
inseparable companion. It is very hard to think or be without it.
Just follow the below steps to recover your lost cell phone:
Calling on your phone: This is the easiest way to find your
handset. Call on your misplaced mobile phone and if it is ringing
then try to find it
If you have any tracker any GPS related app installed in your
smartphone, you can track its location and know its
whereabouts. In android based handsets, you can use an app
called Plan B.

IMPORTANT ETIQUETTES OF USING
CELL PHONES
With increasing number of people, i.e almost all using mobile
phones today, it is also necessary to follow all the etiquettes
of using it, be it in a secluded place, an office or street.
The 6 Etiquettes Of Using Cell Phones Are:
1. When in doubt, always go out of the room / hall
2. If you can’t turn it off, keep it on silent mode
3. When required turn your phone off and also check if it’s
off.
4. Keep your conversations private
5. Speak softly 6. While sitting in a group

GROUP ACTIVITIES
Make a chart and explain with the help of a diagram for Check Basic
Electronic Components Using a Multi-Meter.
Write and show on a chart that how to Check LCD of Cell phone.
Make a chart of parts of a multimeter and
explain each part.
Show the process of different types of
troubleshooting on a chart paper.

SOFT SKILLS -TEAM WORK
Working on teams can be rewarding, but at times it can be difficult
and downright frustrating. If there are poor communicators on your
team, you may often feel left in the dark, confused or misunderstood.
To create a successful team, effective communication methods are
necessary for both team members and leaders.
• Communicate, Communicate!
• Don't Blame Others
• Support Group Member's ideas
• No Bragging
• Listen Actively
• Get Involved

COMMUNICATION SKILLS
Communication is a process, which involves sharing of information
between people through a continuous activity of speaking
listening, and understanding.
Importance of communication:
• Leads to personal effectiveness.
• Helps to network with people.
• Influences motivation for enhanced performance.
• Builds better understanding between boss and subordinates.
• Creates better interpersonal relations.
• Increases listening ability.

COMMUNICATION SKILLS
What is involved in the communication process?
The steps involved in this process are:
• Idea
• Encoding:
• The Channel
• Decoding
• Feedback
• Evaluation
• Understanding
Tips on face-to-face
communication :
• Mannerism
• Thinking
• Courtesy
• . Timing
• Listening
• Structuring
• Styling

NON VERBAL SKILLS AT WORKPLACE
It is the process of communication through sending and
receiving wordless messages.
Non-verbal communication describes all intentional and
unintentional messages that are not written or spoken.
The popular aphorism “Actions speak louder than words”
holds a great deal of meaning when it comes to
understanding the essence of non-verbal communication.

NON VERBAL SKILLS AT WORKPLACE
Characteristics of non-verbal communication:
Convey feeling: up to 93% of emotional meaning is
communicated non-verbally
Form relationships: Establish the nature of relationship
Express truth: nonverbal cues may leak
feelings.
Contextual: Conveys relational
information
Culture Bound:
Gender bound.

IMPROVING LISTENING SKILLS AT
WORKPLACE
One of the most powerful tools for effective, two-way
communication is active listening. We spend more time
listening than we spend at any other method of
communicating.
Active listening is a skill you learn by practice. It takes more
effort than plain „hearing‟ but the benefits make it well
worthwhile. Listening goes beyond hearing. Hearing is a
physiological activity that occurs when sound waves hit our
eardrums.

ORGANIZATIONAL SKILLS
Organizational skills in the workplace can include general
organizing, planning, time management, scheduling,
coordinating resources and meeting deadlines.
An organizational skill is one of the most important
transferable job skills a worker can possess. Companies need
workers who can stay organized and focus on the projects at
hand.

ANALYTICAL THINKING
Analytical thinking skills are methods we can use to analyze,
tackle, and sort new information, ideas, problems, and
solutions.
Some of the most common
analytical skills are:
Organization, Troubleshooting
Communication, Budgeting
Reporting, Research
Data analysis, Diagnostics
Creativity, Metrics,
Analyzing.

Critical thinking is the intellectually disciplined process of
actively and skill fully conceptualizing, applying, analyzing,
synthesizing, and/or evaluating information gathered from, or
generated by, observation, experience, reflection, reasoning,
or communication, as a guide to belief and action.”
Ways to critically think about
information include:
• Conceptualizing
• Analyzing
• Synthesizing
• Evaluating
CRITICAL THINKING

PROBLEM SOLVING & DECISION
MAKING
Definition of a Problem: A problem exists when there is a gap
between what you expect to happen and what actually
happens.
Definition of Decision Making: Decision making is selecting a
course of action from among available alternatives.
Defining the problem: Diagnose a situation so that the focus
is on the real problem, not just on its symptoms. Symptoms
become evident before the problem does.

PLAN AND ORGANISE
Planning is helpful in to figure out which tasks are the most
important and which tasks can wait. Knowing about plan and
organise, you’ll be able to break up your work into smaller pieces
and focus on each task, one at a time, starting with the most
important.
Rules for Planning and Organizing:
Rule # 1 Prioritizing
Rule # 2 Time Management
Rule # 3 Coordinating Resources
Rule # 4 Delegating
Rule # 5 Creating Systems
Rule #6 Planning Ahead

EFFECTIVE WRITTEN COMMUNICATION
In today’s world of rapid-fast communication via texts and emails,
most of us would rather shoot off a written message than make a
phone call. it provides a nice document trail for our work records.
very few people know when writing is the right or wrong.

READING SKILLS
Many people have trouble with reading. Reading well takes
practice!
• Make sure you understand the type of text you have.
• Decide on the purpose of your reading.
• Scan your reading before you begin..
• Read intensively if you want to practice the fundamentals
and learn vocabulary.

GROUP ACTIVITIES
WRITE CUSTOMER LETTERS
Duration: 10 minutes
What You’ll Need: Pen and paper
TELEPHONE
What You’ll Need: Smiling participants
SAY MY NAME
What You’ll Need: Worksheets and a timer

Handset repair Engneer

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