WAEC/NECO Preparatory Classes – SS3 Computer Hardware & GSM Repair Lesson Note (Third Term)

WAEC and NECO revision for Computer Hardware and GSM Repair focuses on four areas: data processing and software, networking and the internet, GSM maintenance and hardware, and safety and ethics. Students should know the definitions, the step-by-step procedures and the labelled diagrams that earn full marks.

Behavioural objectives

By the end of the lesson, students should be able to:

• write and explain basic Excel formulas and identify a cell reference;
• explain a primary key and state the uses of a table, a form and a report in MS Access;
• define a computer virus, state how it spreads and how to prevent it;
• draw and label star, bus and ring topologies and state the work of a modem, a router and a switch;
• identify common GSM repair tools and tell a software fault from a hardware fault;
• state workplace safety rules and computer ethics.

How should you prepare for WAEC and NECO?

You have spent three years learning about computers, phones and data. Now focus on the “Hot Zones”, the topics that WAEC and NECO examiners ask about every year.

Preparing for these exams does not mean reading the whole textbook again. Plan your revision around the definitions, the “How-To” steps and the diagrams that earn full marks. The four areas below cover the main topics.

Area one: data processing and software

Examiners want to know if you can use a computer for work, not just for games.

Spreadsheets (MS Excel)

You will almost always see a question about formulas.

• The rule: Every formula must start with an equal sign (=).
• Common formulas: =SUM(), =AVERAGE(), =MAX(), =MIN().
• Cell referencing: Know how to identify a cell (for example, Column B, Row 4 is B4).

Database management (MS Access)

• Primary key: This is a “golden” topic. It is a unique field that identifies a record (like your admission number or a serial number).
• Tables, forms and reports: A table stores data, a form is for entering data, and a report is for printing results.

Computer viruses

• Definition: A hidden program that “infects” and disrupts the computer.
• Spread: Through flash drives, email attachments and unsafe downloads.
• Prevention: Use updated antivirus software and avoid “pirated” (stolen) software.

Area two: networking and the internet

Examiners want to see if you understand the “cables and signals”.

Network topologies

You must be able to draw these.

1. Star: All computers connect to a central hub or switch.
2. Bus: All computers connect to a single long cable.
3. Ring: Computers connect in a circle.

Networking hardware

1. Modem: Converts signals (digital to analogue and analogue to digital).
2. Router: Directs “traffic” between different networks.
3. Switch: Connects devices within the same office or room.

Internet terms

1. HTTP: The protocol for the Web.
2. WWW: World Wide Web.
3. ISP: Internet Service Provider (for example, MTN, Glo, Airtel).

Area three: GSM maintenance and hardware

If you are taking the Technical/Vocational paper, focus on the “workshop” logic.

Identification of tools

1. Soldering iron: For melting solder to join components.
2. Multimeter: For measuring voltage, current and resistance.
3. DC power supply: For powering a phone without its battery.

Fault finding (troubleshooting)

1. Software fault: The phone hangs at the logo or apps keep crashing. Solution: flashing or hard reset.
2. Hardware fault: A broken screen, a charging port not working, or a “short” on the motherboard.

Area four: safety and ethics

These are easy marks if you remember the “common sense” of the lab.

Workplace safety

• Always wear a lab coat.
• Never eat or drink near a motherboard or a computer.
• Ensure your room is well ventilated to avoid breathing solder fumes.

Computer ethics

• Copyright: Do not steal people’s software or movies.
• Privacy: Do not go through a customer’s private photos during a repair.
• Hacking: Using your skills to break into systems is a crime.

What exam tips should you remember?

• The “Describe” rule: If a question says “Describe”, give more than one sentence. Explain it as if you are teaching a junior student.
• Draw neatly: Use a pencil for diagrams and label them clearly. A labelled diagram is often worth 5 marks on its own.
• Read the instructions: Check whether the paper says “Answer 4 questions” or “Answer all”. Do not waste time answering extra questions.
• Keywords: Use terms like encryption, motherboard, semiconductor and bandwidth. These are the words the markers look for.
• Explain why: If you can explain why a computer behaves a certain way, you are halfway to an A. Also focus on your diagrams, your Excel formulas and your safety rules.

Evaluation

1. The drawing challenge: Without looking at a book, draw a star topology and label the hub.
2. The formula quiz: Write the formula to find the average of the numbers in cells C1, C2, C3 and C4.
3. The tool test: If a phone has a short circuit, which tool from your toolbox will you use to find it?

Assignment

The ethics question: Why is it wrong to install a “cracked” version of Windows for a customer?