Essay. Explain the following.

1. Quality
______________________________________________________________________
______________________________________________________________________
______________________________________________________________________
2. Flow Chart
______________________________________________________________________
______________________________________________________________________
______________________________________________________________________
3. Check Sheet
______________________________________________________________________
______________________________________________________________________
______________________________________________________________________
4. Pareto Diagram
______________________________________________________________________
______________________________________________________________________
______________________________________________________________________

Computer Systems Servicing NC II | 41

Module 3: Performing Computer
Operation (PCO)

Computer Systems Servicing NC II | 42

Learning Competencies:
1. Plan and prepare for task to be undertaken
2. Input data into computer
3. Access information using computer
4. Produce output/ data using computer system
5. Use basic functions of a www- browser to locate information
6. Maintain computer equipment and systems

Preliminary Activity

Decode Me! Computer are found in many places. Find out what these places are by
decoding the words below. Do this by writing the letter of the alphabet that comes after
each given letter. Use A as the letter after Z.

1. KHAQZQX _____________
2. RGNO _____________
3. NEEHBD _____________
4. RSNQD _____________
5. EZBSNQX _____________
6. GNLD _____________
7. AZMJ _____________
8. KZANQZSNQX _____________
9. RBGNNK _____________
10. NTSDQ ROZBD _____________

Computer and Its Types

A computer is an electronic machine that processes and stores information. It takes raw
information using input devices, stores in the memory until it is ready to be processed in
processing unit and sends out result using output devices.

Computers are classified into four (4) different types based on its processing power and
size:
Supercomputer

Minicomputer Classification of Computer Mainframe Computer

Microcomputer
Computer Systems Servicing NC II | 43
Types of Computer

1. Supercomputer is the fastest and most powerful computer in terms of performance

and data processing. It uses power to run one program at a time.
Use in:
a. Research and exploration
b. Weather forecasting
c. Nuclear weapon testing
2. Mainframe computer is not as powerful as the supercomputer. It is designed to run
multiple programs concurrently.
Used in:
a. Banks
b. Educational institution
c. Insurance companies
3. Minicomputer also known as “midrange” computer fill the spaces between the
mainframe and microcomputer. It is smaller than the supercomputer or mainframe
computer but bigger and more powerful than the microcomputer. They are
generally used as mid-range servers.
Used in:
a. Data management device
b. Communication portal
c. Process control
4. Microcomputer is the most widely used computer – desktops, laptops, tablets, and
smartphones. It is the cheapest among the different classes of computers. The
computer is design for general usage such as entertainment, education and work
purposes.

The Elements of Computer System

A computer system is a collection of entities that are designed to receive, process,

manage, and present information in a meaningful format.
Elements of Computer System

Hardware Software Peopleware

1. Hardware refers to the physical, tangible computer equipment and devices which
provides support for major function such as input, output, process and storage.
Components of Computer Hardware

Input Output
Device Device

Process Storage
Device Device

Computer Systems Servicing NC II | 44

 A. Input Devices are composed of device that accepts data and instructions
from the user or from another computer system.
Example:
1. Keyboard
2. Mouse
3. Scanner
4. Microphone

B. Output Device is any piece of computer hardware that display the results
after the computer has processed the input data that has been entered.
Example:
1. Monitor
2. Printer
3. Speaker
4. Projector

C. Process Device is the computer’s circuitry in system unit. It plays an

important role in processing operations. It is used to process data, using
instructions from the program.

Motherboard / Mainboard / System Board is the main circuit board of a

computer. It contains all the circuits and components that run the
computer.

CPU (Central Processing Unit) is the brain or heart of a computer

system. It performs all of the instructions and calculations that are
needed and manages the flow of information through a computer

RAM (Random Access Memory) holds data only when the power is on.

Video Card / Graphics Processing Unit (GPU) also called as display

card, is an expansion card which generates a feed of output images to
a display device.

System Unit also known as a tower or chassis is the main part of a desktop
computer. It encloses motherboard, CPU, RAM, video card and other internal
components.

Other Internal Components of the System Unit

1. Power Supply Unit (PSU)

2. Heat sink
3. Optical Drive

D. Storage Device stores data and programs. These hold data, information,
and programs permanently.

Computer Systems Servicing NC II | 45

 Magnetic Storage Optical Storage Flash Memory
E.
Blu-ray Solid State Drive
Hard Disk Drive

CD Memory Card

Floppy Disk DVD USB Flash Drive

1. Hard Disk Drive is a magnetic storage device that is installed inside the
computer. The HDD is used as permanent storage for data.

2. Floppy Disk is a removable data storage magnetic medium that housed in a

rigid plastic cartridge measuring 3.5 inches square and about 2 millimeters
thick.

3. Blu-ray was designed to supersede DVD format, and is capable of storing

several hours of video in high definition.

4. CD (Compact Disc) is a nonmagnetic, polished metal disc used to store digital

information.

5. DVD (Digital Versatile Disc) single-sided, one-layered disc, which is enough for
a 133-minute movie.

6. Solid State Drive is a storage medium that uses non-volatile memory.

7. Memory Card is a flash memory data storage used with digital camera,
handheld, tablet/mobile.

8. USB Flash Drive is a plug-and-play portable storage device that uses flash
memory and is lightweight enough to attach to a key chain.

2. Software this term refers to the collection of electronic instructions that tells the
computer what to do. It is a computer program that is installed in your computer.

a. System Software coordinates the activities and functions of hardware and

software. It controls the operations of computer hardware and provides an
environment or platform for all of the other types of software to work in. It is the
most basic type of software.

Computer Systems Servicing NC II | 46

 1. Operating System is the program that, after being initially loaded
into computer by a boot program, manages all the other programs
in a computer. Example: Microsoft Windows, MacOS, Linux.

2. Utility Programs are small, powerful programs with a limited

capability, they are usually operated by the user to maintain a
smooth running of the computer system.

b. Application Software is a computer program that performs a specific task.

3. Peopleware the most important element of a computer system is its users.

1. System Analysts are people who design the operation and

processing of the system.
2. System Programmers are people who write codes and
programs to implement the working of the system.
3. System Operators are people who operate the system and use
it for different purposes.

Common Computer Applications Used in Performing Computer Related Duties

1. Microsoft Office Application is a package application developed by Microsoft and

is intended to be used in offices and schools.
a. MS Word is a word processing application used for creating documents
such as letters, brochures, etc.
b. MS Excel is a spreadsheet program ideal for entering, calculating, and
analyzing numeric data such as sales, students’ grades, etc.
c. MS PowerPoint is a presentation tool that uses graphical approach to
presentation form of slides.

2. Photo Editing Software is commonly used in editing and enhancing photos that
would give you an excellent output.

3. Video Editing Software is used to edit movies or movie clips.

4. Web Browsers is an application used to access information on the World Wide

Web.

Assessment

Classify the following devices. Write ID for Input Device, PD for Process Device, OD for
Output Device and SD for Storage Device.

__________ 1. Mouse
__________ 2. Printer
__________ 3. Monitor

Computer Systems Servicing NC II | 47

 __________ 4. USB Flash Drive
__________ 5. Speaker
__________ 6. Hard Disk Drive
__________ 7. Keyboard
__________ 8. SSD
__________ 9. Scanner
__________ 10. GPU

Fill in the missing word/s to complete the sentence.

1. A _____________ is an electronic machine that processes and stores information.

It takes raw information using _____________ devices, stores in the memory until
it is ready to be processed in processing unit and sends out result using
_____________ devices.
2. A __________________________ is a collection of entities that are designed to
receive, process, manage, and present information in a meaningful format. It has
three elements: _____________, _____________ and _____________.
3. _____________ refers to the physical, tangible computer equipment and devices
which provides support for major function such as input, _____________, process
and _____________.
4. __________________________ are composed of device that accepts data and
instructions from the user or from another computer system.
5. __________________________ is any piece of computer hardware that display
the results after the computer has processed the input data that has been entered.
6. __________________________ is the computer’s circuitry in system unit. It plays
an important role in processing operations.
7. __________________________ stores data and programs. These hold data,
information, and programs permanently.
8. _____________ this term refers to the collection of electronic instructions that tells
the computer what to do. It is a computer program that is installed in your computer.
9. __________________________ is an application used to access information on
the World Wide Web.
10. __________________________ is a package application developed by Microsoft
and is intended to be used in offices and schools.
11. _____________ Software is used to edit movies or movie clips.
12. _____________ Software is commonly used in editing and enhancing photos that
would give you an excellent output.
13. _____________ the most important element of a computer system is its users.
14. __________________________ is a storage medium that uses non-volatile
memory.
15. __________________________ is the program that, after being initially loaded
into computer by a boot program, manages all the other programs in a computer.

Computer Systems Servicing NC II | 48

Activity. Finger Keyboarding. Draw a diagram of proper hand position using keyboard and
label each finger with the keys assigned. Draw inside the box below.

Computer Systems Servicing NC II | 49

OHS Policies and Procedures

OHS or Occupational Health and Safety refer to the legislation, policies,

procedures and activities that aim to protect the health, safety and welfare of all people
at the workplace.

1. Do not work alone so that someone can take care of you in case of emergency.
2. Always power off the computer and unplug the computer before working on it.
3. Take away any liquid near your working area to avoid getting electrocuted or
accidentally damaging computer parts.
4. Be careful with tools that may cause short circuit.
5. Always ground or discharge yourself before touching any parts of the computer.
6. Do not use excessive force if things don’t quite slip into place.
7. Clean the area before and after using it to maintain sanitation and prevent
accidents.
8. Hold the components on the edges and do not touch the Integrated Circuit parts.
9. Always wear personal protective equipment (PPE) in accordance with the
organization’s OHS procedures and practices.
10. Make sure that the pins are properly aligned when connecting a cable connector.
11. Emergency measures during workplace accidents, fire, and other emergencies are
recognized.
12. Use brush, compressed air or blower in cleaning the computer system.

5S for the Personal Computer

WHEN IN A PLACE CLEAN AND MAKE UP PART OF

SET IN ORDER

SUSTAIN
SORT

SHINE

STANDARDIZE

DOUBT, FOR INSPECT OR THE RULES, DAILY WORK

MOVE IT EVERYTHING INSPECT FOLLOW AND IT
OUT - RED AND THROUGH AND BECOMES A
TAG EVERYTHING CLEANING ENFORCE HABIT
TECHNIQUE IN ITS PLACE THEM

Step 1: SORT (SEIRI)

Too many unused files and folders slow you and your computer down. Remove or
discard what is not needed so that there are fewer hazards and less clutter to interfere
with work. Only keep what is needed.

Step 2: SET IN ORDER (SEITON)

There must be place for everything. Organize your files and folders to reduce
clutter and allow for instant access:
1. Establish a naming convention for files. This will make files easier to
locate.
2. Create a folder system for organizing your work.

Computer Systems Servicing NC II | 50

Step 3: SHINE (SEISO)
1. Cleaning your computer and check your computer for problems:
a. Clean your computer screen
b. Clean your keyboard
c. Clean all cables and ensure free from dust
d. Clean computer main box
e. Run system diagnostic/maintenance utilities
i. Anti-virus
ii. Disk Defragmentation
iii. Anti-spyware
f. Clean the start menu

Step 4: STANDARDIZE (SEIKETSU)

Develop consistency in practices over time.

Step 5: SUSTAIN (SHITSUKE)

Allocate 5 minutes a week to run through organization of your PC. Remember, 5
minutes can save the effort you spend to search through unnecessary clutter.

Posture Perfect

Ergonomics is the science of designing equipment for safe and comfortable

working environment.

1. Sit up straight
2. Place your feet flat on the floor
3. Your elbows should be bent at a right angle at your side
4. Make sure your monitor is right in front of you
5. Look away from the computer every few minutes to rest your eyes
6. When working on the computer for a long time, take frequent short breaks
7. Do not squeeze the mouse
8. Use an optical glass antiglare filter when needed

Basic Computer System Maintenance

Computer Maintenance is the practice of keeping computers in a good state of

repair.

1. Folders – are used to organize and categorize files in your computer storage.
2. Antivirus – use to check your computer, flash drive and other storage devices for
any files infected with viruses and malware.
3. Backup
4. System Update

Computer Systems Servicing NC II | 51

Activity
Organize your desktop. Listed below are the files you need to sort. There are 4 folders.
Sort the given files accordingly based on the folder.

FILES FOLDER NAME

1. Long Live by Taylor Swift.mp3
2. Edward Graduation Picture.jpg
3. CSS Part 1 Report.pptx
4. Letter of Intent to Teach.docx
5. Kundiman by Silent Sanctuary.mp3
6. Graduation AVP.mp4
7. Inside Out 2.mp4
8. CGC Logo.png
9. CGC Hymn with Lyrics.mp4
10. Sports Fest 2024 Opening.mp3

True or False. Write T if the statement is true, otherwise put F if the statement is false.

_______ 1. Work alone so that someone can take care of you in case of emergency.
_______ 2. Always power on the computer and plug the computer before working on it.
_______ 3. Take away any liquid near your working area to avoid getting electrocuted or
accidentally damaging computer parts.
_______ 4. Be careful with tools that may cause short circuit.
_______ 5. Always ground or discharge yourself before touching any parts of the
computer.
_______ 6. Use excessive force if things don’t quite slip into place.
_______ 7. Clean the area before and after using it to maintain sanitation and prevent
accidents.
_______ 8. Do not hold the components on the edges and touch the Integrated Circuit
parts.
_______ 9. Always wear personal protective equipment (PPE) in accordance with the
organization’s OHS procedures and practices.
_______ 10. Make sure that the pins are properly aligned when connecting a cable
connector.

Computer Systems Servicing NC II | 52

Module 4: Performing Mensuration and
Calculation (PMC)

Computer Systems Servicing NC II | 53

Learning Competencies:
1. Select measuring instruments
2. Carry out measurements and calculation
3. Maintain measuring instruments

COMMONLY USED MEASURING TOOLS AND INSTRUMENTS

Component Function of Component

A steel rule – an instrument used in geometry,

technical drawing and engineering/building to
measure distances and/or to rule straight lines.

Push-Pull Rule – a step of steel marked off in

inches or Centimeters used in measuring

A protractor – a circular or semicircular tool for

measuring an angle or a circle. The units of
measurement utilized are usually degrees.

A sliding bevel – a simple hand tool made up of a

stainless steel blade, a plastic or wooden handle
and a locking mechanism. The blade can be
adjusted to any acute or obtuse angle and locked
in place, so that the angle can be repeatedly
marked on other pieces of stock.

Combination square - is a tool used for multiple

purposes in woodworking and metalworking. The
Square refers to the primary use of the tool:
measuring the accuracy of a right angle (90°).
At its minimum, the tool is composed of primarily
two parts: a rule and a head.

Computer Systems Servicing NC II | 54

Try square is a woodworking or a metal working
tool used for marking and measuring a piece of
wood. The square refers to the tool's primary use of
measuring the accuracy of a right angle (90
degrees); to try a surface is to check its
straightness or correspondence to an adjoining
surface. A piece of wood that is rectangular, flat,
and has all edges (faces, sides, and ends) 90
degrees is called four square. A board is often
milled four square in preparation for using it in
building furniture

Analog multimeters are sometimes referred to as

"volt-ohm-meters", abbreviated VOM is an
electronic measuring instrument that combines
several functions in one unit. They are
traditionally harder to use because you must
select the type and range of voltage you are testing,
find proper scale on the meter face, and the
estimate the voltage as the needle swings into
action.

Digital multimeters are usually referred to as

"digital-multi-meters", abbreviated DMM. Displays
the voltage in clear numerals and with a greater
precision than most analog meters.

Computer Systems Servicing NC II | 55

COMMON MATHEMATICAL PREFIXES

PREFIX SYMBOL MATHEMATICAL EQUIVALENT

Exa E 1018 or (1 000 000 000 000 000 000)
Peta P 1015 or (1 000 000 000 000 000)
Tera T 1012 or (1 000 000 000 000)
Giga G 109 or (1 000 000 000)
Mega M 106 or (1 000 000)
Kilo K 103 or (1 000)
Hecto H 102 or (100)
Deka Da 101 or (10)
Deci d 10-1 or (0.1)
Centi c 10-2 or (0.01)
Milli m 10-3 or (0.001)
Micro u 10-6 or (0. 000 001)
Nano n 10-9 or (0. 000 000 001)
Pico P 1012 or (0. 000 000 000 001)
Femto F 1015 or (0. 000 000 000 000 001)
Atto A 1018 or (0. 000 000 000 000 000 001)

A. CONVERSION OF UNITS (ENGLISH TO METRIC AND VISE-VERSA)

Length 1 meter = 3.28 feet 1 liter = 1.06 quarts

1 mile = 1.61 kilometers 1 centimeter = 0.394 in
1 yard = 0.914 meter Weight
1 foot = 0.305 meter Volume 1 pound= 0.454 kilogram
1 inch = 2.54 centimeters 1 gallon = 3.79 liters 1 ounce = 28.35 grams
1 kilometer = 0.62 mile 1 quart = 0.946 liter 1 kilogram = 2.2 pounds
1 meter = 1.09 yard 1 liter = 0.264 gallon 1 gram = 0.0353 ounce

B. OHM’S LAW

Ohm’s law, description

of the relationship
between current,
voltage, and resistance.
The amount of steady
current through a large
number of materials is
directly proportional to
the potential difference,
or voltage, across the
materials. Thus, if the
voltage V (in units of
volts) between two ends
of a wire made from one

Computer Systems Servicing NC II | 56

of these materials is tripled, the current I (amperes) also triples; and the quotient V/I
remains constant. The quotient V/I for a given piece of material is called its resistance, R,
measured in units named ohms. The resistance of materials for which Ohm’s law is valid
does not change over enormous ranges of voltage and current. Ohm’s law may be
expressed mathematically as V/I = R. That the resistance, or the ratio of voltage to
current, for all or part of an electric circuit at a fixed temperature is generally constant had
been established by 1827 as a result of the investigations of the German physicist Georg
Simon Ohm.

Assessment

I. Convert the following using unit of measurement. You can use scratch paper
for your computation. Just write in the space your final answer.
A. Length
1. 25 miles = ___________ kilometers
2. 2.5 yards = ___________ meters
3. 4 foot = ___________ meters
4. 12 inches = ___________ centimeters
5. 200 kilometers = ___________ miles
6. 15 meters = ___________ yards
7. 8 meters = ___________ foot
8. 10 centimeters = ___________ inches
9. 12 inches = ___________ foot
10. 10 yards = ___________ meters

B. Volume
1. 100 gallon = ___________ liters
2. 15 quart = ___________ liters
3. 1.5 liters = ___________ gallons
4. 25 liters = ___________ quarts
5. 25 quart = ___________ liters

C. Weight
1. 110 pounds = ___________ kilograms
2. 12 ounces = ___________ grams
3. 53 kilograms = ___________ pounds
4. 1500 grams = ___________ ounces
5. 10 kilograms = ___________ pounds

Computer Systems Servicing NC II | 57

II. Solve the following using the Ohm’s Law.

1. What is the voltage if a resistance of 25 Ω produces a current of 250 amperes?

Given:

Unknown:

Formula:

Substitution/Solution:

Final Answer:

2. What is the current produced by a voltage of 240 V through a resistance of 0.2 Ω?

Given:

Unknown:

Formula:

Substitution/Solution:

Final Answer:

3. What voltage is necessary to produce a current of 200 amperes through a

resistance of 100 Ω?

Given:

Unknown:

Formula:

Computer Systems Servicing NC II | 58

 Substitution/Solution:
Final Answer:

4. What resistance would produce a current of 120 amps from a 6-V battery?

Given:

Unknown:

Formula:

Substitution/Solution:

Final Answer:

5. What is the voltage if a resistance of 35 Ω produces a current of 500 amperes?

Given:

Unknown:

Formula:

Substitution/Solution:

Final Answer:

Computer Systems Servicing NC II | 59

NUMBER SYSTEM

Number System

Binary Number Octal Number Decimal Number Hexadecimal

System System System Number System

Based 16
Represented by Represented by Represented by Represented by
(example:
"0" and "1" "0-7" "0-9" "0-9" and "A-F"
12AB16)

Base 10 A=10; B=11;

Base 2 (example: Base 8 (example:
(example: C=12; D=13;
10102) 12345678)
12345678910) E=14; F=15

Golden Rule:
- Any number raised to zero is always equal to 1, example: 20=1
- Any number you multiply to zero is always equal to 0, example: 2x0=0
- Any power given, meaning you multiply it to itself, example: 24= 2x2x2x2=16

Conversion of Number System

1. Binary Number System to Decimal Number System

Example:
a. 1102=____________10
= (1x22) + (1x21) + (0x20)
=4+2+0
=6

b. 101102=____________10
= (1x24) + (0x23) + (1x22) + (1x21) + (0x20)
= 16 + 0 + 4 + 2 + 0
= 22

2. Decimal Number System to Binary Number System

Example:
a. 2410=____________2

Computer Systems Servicing NC II | 60