Procedures for Repairing Faulty Keypads, Speakers and Screens for SS 1

Class: SS 1
Term: Third Term
Week: 2
Age: 15 years
Duration: 60 minutes
Subject: Computer Hardware and GSM Repairs
Curriculum Theme: Hardware Assembly, Maintenance,
Focal competence: Replacement of faulty components of computer and mobile phones
Key competencies/values: Creativity and Innovation; Collaboration; Resilience; Innovation
Skills:

• Fixing faulty keypads, speaker, screen damaged, faulty keypad

Previous Lesson:
Topic: Simple Repairs: Procedures For Fixing Faulty Keypads, Speaker, Screen Damaged, Faulty Keypad
Subject Matter: Procedures for fixing faulty keypads, speaker, screen damaged, faulty keypad

Specific Objectives

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

Cognitive Domain

• State the procedures for fixing faulty keypads.
• Identify faulty components in mobile phones and computers.
• Relate physical components to their basic functions.

Affective Domain

• Appreciate the importance of careful handling and organisation during repairs.
• Demonstrate patience and attention to detail when performing repairs.

Psychomotor Domain

• Demonstrate the safe use of screwdrivers and pliers for disassembling and assembling devices.
• Perform basic steps in fixing faulty keypads, speakers, and screens.

Social Domain

• Collaborate effectively in groups to brainstorm and perform repair procedures.
• Communicate findings and repair steps clearly with peers.

Reference Materials

The following resources were used in planning this lesson:

• 2025 New Revised Senior Secondary Education Curriculum (SSEC)
• Relevant State Unified Scheme of Work
• Computer Hardware and GSM Repairs for Senior Secondary Schools, Book 1
• The HeadTeacher Scheme of work For The New Revised Senior Secondary Education Curriculum (SSEC)

Instructional Materials

The teacher will teach this lesson with the aid of:

• Faulty mobile phones
• Faulty computers (laptops or desktops)
• Workstation with adequate lighting
• Screwdriver sets (precision and standard)
• Pliers (needle-nose, flat-nose)
• Multimeter/testers
• Cleaning solution and lint-free cloths
• Replacement keypads, speakers, and screens (if available for demonstration)

Rationale for the Lesson

This lesson is important as it equips students with practical skills in identifying and performing basic repairs on common computer and mobile phone components. Understanding these procedures fosters problem-solving abilities and promotes a foundational understanding of hardware maintenance. It also introduces students to safe handling practices essential for any technical repair work.

Prerequisite/Previous Knowledge

Students should have basic knowledge of computer and mobile phone components and their general functions. They should also be familiar with the names of common hand tools.

Lesson Content/Board Summary

Simple Repairs: Procedures For Fixing Faulty Keypads, Speaker, Screen Damaged, Faulty Keypad

Identification of Faulty Components

Identifying a faulty component is the first step in any repair process. This involves observing symptoms and sometimes using diagnostic tools.

1. Faulty Keypad: Symptoms include unresponsive keys, sticky keys, keys typing incorrect characters, or no input registered at all.
2. Faulty Speaker: Symptoms include no sound, distorted sound, low volume even at maximum settings, or crackling noises.
3. Damaged Screen: Symptoms include cracks, lines, dead pixels, flickering display, discolouration, or a completely blank screen.

Basic Functions of Key Components

Understanding the basic function of each component helps in diagnosing and repairing faults.

1. Keypad: Allows users to input data (text, numbers, commands) into the device by converting key presses into electrical signals.
2. Speaker: Converts electrical audio signals into sound waves, enabling the device to produce audible output like music, calls, and system alerts.
3. Screen (Display): Presents visual information to the user, converting electrical signals into images and text.

Safe Handling and Organisation Practices

Proper safety and organisation are crucial for successful and safe hardware repairs.

1. Power Off: Always ensure the device is completely powered off and disconnected from any power source before starting repairs. Remove the battery if possible.
2. Anti-Static Precautions: Use an anti-static wrist strap or mat to prevent electrostatic discharge (ESD), which can damage sensitive electronic components.
3. Organise Components: Keep screws and small parts organised (e.g., in a compartmentalised tray or labelled containers) to ensure they are reassembled correctly. Note the location of each screw.
4. Use Correct Tools: Use the appropriate tools for each task (e.g., precision screwdrivers for small screws) to avoid stripping screws or damaging components.
5. Gentle Handling: Handle components, especially delicate ones like screens and flex cables, with extreme care to prevent further damage.
6. Cleanliness: Work in a clean, well-lit environment to prevent dust or debris from entering the device.

Procedures for Fixing Faulty Keypads

The procedure for fixing a faulty keypad depends on the nature of the fault.

1. Disassembly: Carefully open the device (mobile phone or laptop) using appropriate screwdrivers and prying tools.
2. Locate Keypad: Identify the keypad assembly and its connection (usually a flex cable).
3. Cleaning (for sticky/unresponsive keys):
   1. Disconnect the keypad flex cable.
   2. Gently remove the keypad membrane or individual keys if possible.
   3. Clean the contact points on the keypad and the circuit board with isopropyl alcohol and a lint-free cloth or cotton swab.
   4. Allow to dry completely.
4. Replacement (for severely damaged or non-functional keypads):
   1. Disconnect the old keypad flex cable.
   2. Carefully remove the faulty keypad assembly.
   3. Install the new keypad, ensuring proper alignment.
   4. Reconnect the flex cable securely.
5. Reassembly: Carefully reassemble the device, ensuring all screws and components are in their correct positions.
6. Testing: Power on the device and test all keys to confirm functionality.

Procedures for Fixing Faulty Speakers

Repairing a faulty speaker often involves cleaning or replacement.

1. Disassembly: Open the device carefully to access the speaker component.
2. Locate Speaker: Identify the speaker module, which is usually connected by wires or contact pads.
3. Check for Obstructions: Inspect the speaker grille for dust, debris, or foreign objects blocking the sound. Clean with a soft brush or compressed air.
4. Check Connections: Ensure the speaker’s wires or contact pads are securely connected to the main circuit board. Re-solder loose connections if necessary (advanced).
5. Replacement (for damaged or non-functional speakers):
   1. Disconnect the faulty speaker.
   2. Carefully remove the old speaker module.
   3. Install the new speaker, ensuring correct orientation and secure connections.
6. Reassembly: Put the device back together, ensuring all components are properly seated.
7. Testing: Test the speaker functionality by playing audio at various volumes.

Procedures for Fixing Damaged Screens

Fixing a damaged screen almost always requires replacement.

1. Disassembly: Carefully open the device, often requiring heating the screen edges to loosen adhesive (especially for mobile phones).
2. Disconnect Battery: Always disconnect the battery first to prevent short circuits.
3. Disconnect Flex Cables: Locate and carefully disconnect the screen’s display and digitiser (touch) flex cables from the main board.
4. Remove Damaged Screen: Gently pry off the damaged screen from the device frame. Be cautious of broken glass.
5. Clean Frame: Clean any residual adhesive or glass fragments from the device frame.
6. Install New Screen:
   1. Connect the new screen’s flex cables to the main board.
   2. Test the new screen functionality (display and touch) before fully adhering it.
   3. Apply new adhesive to the device frame.
   4. Carefully seat the new screen into the frame, ensuring proper alignment.
7. Reassembly: Reconnect the battery and reassemble the device.
8. Final Test: Power on and thoroughly test the new screen’s display, touch response, and overall functionality.

Teaching Methods/Instructional Techniques

Discussion, Demonstration, Guided Practice, Question and Answer, Explanation, Observation, Group Work, Practical Activity.

Instructional Procedures

Step 1: Introduction

Time: 5 minutes

Teaching Skill: Questioning/Engagement

Teacher’s Activity: The teacher greets the students and asks them about common problems they or their family members have experienced with mobile phone keypads, speakers, or screens. The teacher then introduces the topic: “Simple Repairs: Procedures For Fixing Faulty Keypads, Speaker, Screen Damaged, Faulty Keypad.”

Pupils’ Activity: Pupils respond to the questions and listen attentively to the topic introduction.

Learning Point: Common hardware faults

Step 2: Identifying Faulty Components and Functions

Time: 10 minutes

Teaching Skill: Explanation/Demonstration

Teacher’s Activity: The teacher displays faulty mobile phones and computers. The teacher guides students to identify the faulty components (keypad, speaker, screen) and explains the basic function of each component. The teacher also highlights the symptoms of each fault.

Pupils’ Activity: Pupils observe the faulty devices, identify the components, and listen to the explanations of their functions and fault symptoms.

Learning Point: Component identification and function

Step 3: Discussing Safe Handling Practices

Time: 10 minutes

Teaching Skill: Discussion/Explanation

Teacher’s Activity: The teacher leads a discussion on the importance of safe handling, organisation, and fault-awareness practices during hardware repairs. The teacher explains key safety precautions like powering off, anti-static measures, and proper tool use.

Pupils’ Activity: Pupils participate in the discussion, ask questions, and note down important safety practices.

Learning Point: Safe repair practices

Step 4: Brainstorming Repair Procedures (Group Activity)

Time: 10 minutes

Teaching Skill: Group Facilitation/Brainstorming

Teacher’s Activity: The teacher divides students into groups and guides them to brainstorm the general procedures for fixing faulty components based on their understanding and the previous discussions. Each group is encouraged to think about the steps involved in opening, identifying, fixing, and reassembling.

Pupils’ Activity: Students work in groups, discussing and brainstorming repair procedures for different components.

Learning Point: General repair steps

Step 5: Demonstrating Keypad Repair Procedures

Time: 5 minutes

Teaching Skill: Demonstration/Explanation

Teacher’s Activity: The teacher demonstrates the step-by-step procedures for fixing a faulty keypad using a faulty mobile phone or computer. The teacher emphasises careful disassembly, cleaning, and reassembly.

Pupils’ Activity: Pupils observe the teacher’s demonstration carefully, paying attention to the tools used and the sequence of steps.

Learning Point: Keypad repair steps

Step 6: Demonstrating Speaker and Screen Repair Procedures

Time: 5 minutes

Teaching Skill: Demonstration/Explanation

Teacher’s Activity: The teacher continues the demonstration, showing the basic procedures for fixing a faulty speaker and a damaged screen, highlighting the differences in approach for each component, especially the need for replacement for screens.

Pupils’ Activity: Pupils continue to observe and ask questions about the speaker and screen repair demonstrations.

Learning Point: Speaker, screen repair

Step 7: Evaluation/Review

Time: 5 minutes

Teaching Skill: Questioning/Assessment

Teacher’s Activity: The teacher evaluates the learning by asking the following questions:

1. State three procedures for fixing a faulty keypad.
2. How would you identify a faulty speaker?
3. Mention two safety precautions to observe when repairing a mobile phone.
4. Why is it important to organise small parts during repair?

Pupils’ Activity: Pupils answer orally and in writing.

Learning Point: Understanding repair procedures

Step 8: Note-Taking

Time: 10 minutes

Teaching Skill: Guided Writing

Teacher’s Activity: The teacher guides pupils/students to copy the essential Board Summary notes on identifying faults, safe handling, and repair procedures for keypads, speakers, and screens into their notebooks.

Pupils’ Activity: Pupils/students copy the notes carefully into their notebooks.

Learning Point: Recording lesson content

Step 9: Conclusion

Time: 5 minutes

Teaching Skill: Consolidation

Teacher’s Activity: The teacher summarises the key takeaways of the lesson, reiterating the importance of careful observation, proper tools, and systematic procedures in hardware repair. The teacher encourages students to practice these skills responsibly.

Pupils’ Activity: Pupils listen to the summary and ask any final clarifying questions.

Learning Point: Lesson summary and application

Continuous Assessment/Further Study

Type: Homework/Practical Exercise

Instruction: Answer the following questions and, if possible, observe a professional repairing a mobile phone or computer to identify the steps they follow.

1. Describe the symptoms of a damaged screen and what typically needs to be done to fix it.
2. List the tools you would need to open a mobile phone for repair.
3. Explain why disconnecting the battery is a crucial first step when repairing electronic devices.
4. Research and write down two additional safety precautions for handling electronic components.

Lesson Keywords

• Keypad – An input device consisting of an array of buttons, typically for entering numbers or text.
• Speaker – An output device that converts electrical audio signals into sound waves.
• Screen – The display component of an electronic device that shows visual information.
• Disassembly – The process of taking apart an electronic device into its component parts.
• Reassembly – The process of putting an electronic device back together after repair.
• Flex cable – A flexible printed circuit board used to connect components in compact electronic devices.
• ESD (Electrostatic Discharge) – The sudden flow of electricity between two electrically charged objects, which can damage electronic components.

Differentiation

Support: Provide simplified diagrams of device disassembly and reassembly. Pair students with stronger peers for group activities and practical demonstrations. Offer pre-labelled trays for organising screws and small parts.

Extension: Challenge advanced students to research common issues with other components (e.g., charging ports, cameras) and propose repair steps. Encourage them to identify specific tools required for more complex repairs or to research different types of screens (LCD, OLED) and their repair considerations.

Suggested Lesson Videos

Search on YouTube for: mobile phone repair basics keypad speaker screen SS1