Project Execution SS3 Computer Hardware & GSM Repair Lesson Note

Subject: Computer Hardware and GSM Repair 

Class: SS3

Topic: Carrying Out Your Project: From Plan to Reality

The “Work” Begins

You have done your research, written your proposal, and gotten your supervisor’s approval. Now, it is time to move from paper to the workbench. Project Execution is the most exciting part of your final year—it is where you actually use your hands to bring a dead device back to life or build a new system.

However, execution is not just about jumping in and melting solder. It is about following a professional “Process” to ensure you don’t make mistakes that destroy your hard work.

Preparing Your Workspace

Before you touch the customer’s phone or the computer motherboard, your “Lab” must be ready. A messy desk leads to lost screws and “surprises.”

The Professional Setup:

• The ESD Zone: Always use an Anti-Static mat. One tiny spark from your finger (Static) can kill a CPU before you even start the repair.
• Lighting: You cannot fix what you cannot see. Ensure you have a bright desk lamp or a microscope light.
• Tool Check: Line up your tools. Do you have your Multimeter, DC Power Supply, Soldering Iron, and Tweezers ready?
• Safety First: Have your safety glasses on and ensure your room has a window open or a fan to blow away solder fumes.

The “Before” Documentation

A professional technician always documents the starting point. Before you open any screw:

1. Visual Check: Take a photo of the device. Does it have scratches? Is the screen already cracked?
2. Initial Testing: If the device still powers on, test the basics—Camera, WiFi, Charging, and Sound. Write these down in your “Project Diary.”
3. The Diagnosis: Use your DC Power Supply to see the current consumption. Is it a “Full Short” or “No Power”? Record the numbers.

Step-by-Step Execution

This is the heart of your project. Whether you are doing a “BGA Reballing” or “Jumpering” a broken track, follow these rules:

1. Opening the Device:

Go slow. Many modern phones use strong glue. Use a heat mat or heat gun (set to 80°C – 90°C) to soften the glue. Use plastic tools, not metal, so you don’t scratch the frame.

1. Troubleshooting with Schematics:

Don’t just guess which chip is bad. Open your Schematic Viewer (like Borneo or DZKJ).

• Trace the power line.
• Measure the voltages at “Test Points.”
• If the schematic says you should see 3.8V but you see 0V, you have found the “leak” in the circuit!

1. The Repair (Soldering/Hardware):

• Flux is your friend: Always use enough flux to help the solder flow.
• Temperature Control: Don’t keep the hot air gun on one spot for too long, or the board will “pop.”
• Steady Hands: If you feel tired or shaky, take a 5-minute break. Precision requires a calm mind.

Testing and “Quality Control”

Once you have replaced the faulty part or fixed the connection, do not close the device yet.

• The Bench Test: Connect the board to the DC Power Supply again. Is the “Short” gone? Does it pull a normal amount of current now?
• Partial Assembly: Put the screen and battery back temporarily. Does it show the logo?
• Full Functional Test: Check the things you might have disturbed. Does the mic still work? Is the home button clicking?

Managing Failures (The “Pivot”)

Sometimes, you follow every step and the project still doesn’t work. Do not panic.

• Re-trace your steps: Did you put a capacitor in the wrong way? (Polarity).
• Consult your Diary: Look at your notes from yesterday. What changed?
• Ask for Guidance: Show your supervisor your progress. Sometimes a second pair of eyes sees the tiny solder bridge you missed.
• Document the Failure: Even if it doesn’t work perfectly, explaining why it failed in your report can still earn you a good grade!

Summary

Execution is where you prove you are a technician. It requires a mix of Cleanliness, Patience, and Logic. Keep your workbench organized, follow your schematic like a map, and never rush the process. Your final project is a reflection of your professional character.

Review & Practical Task

1. Why is it important to test the “Camera and WiFi” before you even start a motherboard repair?
2. What is the danger of using a metal tool to pry open a phone case?
3. Describe what you should do if you feel your hands shaking while trying to solder a tiny jumper wire.
4. Why should we record the “Current Reading” from the DC Power Supply at every stage of the repair?