Final Project I – JSS3 Computer Hardware & GSM Repair Lesson Note (Third Term)

The final project is a practical task in which you act as a lead technician and repair a faulty mobile phone from first inspection to handover.

Behavioural objectives

1. State the three parts of the technician’s mindset.
2. Carry out a pre-repair inspection and record the findings on a job card.
3. Disassemble a phone safely, keeping screws and parts in order.
4. Install a new part, run a dry test and seal the phone correctly.
5. Complete a quality control checklist and hand the phone to the client with a warranty and receipt.

What is the final project?

The final project is a full repair of one mobile phone that has a common fault.

• Task: take a phone with a fault such as a broken screen or a bad charging port.
• Diagnose: find out exactly what is wrong.
• Fix: remove the faulty part and fit a good one.
• Test: make sure the phone works well for the “client”.
• Role: you act as the lead technician, from the first check to the final payment.

What is the technician’s mindset?

The technician’s mindset is the set of three habits you must keep before and during every repair.

1. Safety: protect yourself and the device.
2. Order: keep your screws and parts organised.
3. Patience: if a part is stuck, find out why. Do not force it.

What tools and materials are needed?

A repair needs a small set of tools and materials, each with one clear use.

What is a pre-repair inspection?

A pre-repair inspection is the set of checks you make before opening the phone (Phase 1).

• Power: does the phone turn on?
• Screen: is the screen cracked or bleeding?
• Buttons: do the volume and power buttons click properly?
• Job card: write every finding down before you start.

Why is the job card important?

• It records the state of the phone when it arrived.
• It protects you if the customer blames you for a fault that was already there.

How do you disassemble a phone?

Disassembly is the careful removal of the back cover, battery connection, screws and the faulty part.

Step 1: The power cut

• As soon as the back cover is off, disconnect the battery.
• Electricity can remain on the board even when the phone is off.
• A slip of a metal tool can cause a spark that damages the phone permanently.

Step 2: Managing the screws

• Modern phones use screws of different sizes.
• Screw map: draw a rough shape of the phone on paper.
• Place each screw on the drawing exactly where it came from.
• This stops you putting a long screw into a short hole later.

Step 3: Removing the faulty part

This applies to a screen, a speaker or any other part.

1. Use a hot air station if the part is glued down.
2. Use a plastic pick to lift the edges gently.
3. Disconnect the ribbon cable with a plastic tool.

• Ribbon cable: the flat cable that links the part to the motherboard, like an “umbilical cord”.

What are the common faults and the parts to check?

Each common fault points to a part you should check first.

How do you install and test the new part?

Installation has three phases: cleaning the frame, a dry test and final sealing.

Phase 2: Cleaning the bed

• Clean the frame before fitting the new part.
• Old glue or tiny pieces of glass stop the new screen from sitting flat.
• An uneven screen may crack when you press it.
• Use a small brush and isopropyl alcohol (IPA) until the frame is shiny and clean.

Phase 3: The dry test

A dry test is a full check of the new part before any glue is used.

1. Connect the new part’s cable to the motherboard.
2. Connect the battery.
3. Turn the phone on and test it.
4. Check that touch works everywhere on the screen.
5. Check that the colour is bright.
6. If it works, turn the phone off and go to final assembly.

• If it fails: you can return the part to the seller, because it has no glue on it.

Phase 4: Final sealing

1. Apply a thin line of B7000 glue (or similar phone glue) around the frame.
2. Lay the screen down on the frame.
3. Hold it tight with rubber bands for about 30 minutes while the glue sets.

What is the quality control (QC) checklist?

The QC checklist is a list of five checks you make before returning the phone, because a repair is not finished until the customer is happy.

1. Charging: does it show the charging sign?
2. Sound: do the loudspeaker and earpiece work?
3. Network: does it show network bars, such as MTN or Airtel?
4. Camera: are the front and back cameras clear, with no dust inside?
5. Cleanliness: wipe off your fingerprints with a soft cloth.

How do you hand the phone over to the client?

The business handover is the last step, where you show the repair, explain the warranty and collect payment.

• Show the repair: let the client see that the fault is fixed.
• Warranty: a promise to put right faults from your repair within a stated period.
• Warranty example: “This screen has a 7-day warranty, but it does not cover it if you drop it or it falls in water again.”
• Receipt: issue a receipt and collect your payment.
• Honesty: always tell the customer the truth about the repair.

Evaluation

1. State the three parts of the technician’s mindset.
2. Why must you disconnect the battery as soon as the back cover is off?
3. Why is it important to test the screen before applying glue?
4. List the five checks on the QC checklist.

Assignment

Write a job card for a phone with a cracked screen. List three things you would check before opening it. Then write the repair steps in order, from disconnecting the battery to handing the phone over.