Computer Assembly I – SS1 Computer Hardware & GSM Repair Lesson Note (First Term)

Computer assembly is the step-by-step process of fitting hardware parts into a computer case.

• Parts installed in this lesson: the power supply unit (PSU), the RAM and the hard drive (HDD) or SSD.
• Skill needed: a gentle touch, patience and the habit of following a fixed order.
• Safety rule: prepare the work area first and check everything before connecting power.

Behavioural objectives

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

1. Prepare a safe work area before assembling a computer.
2. Install a power supply unit (PSU) in a computer case.
3. Install RAM correctly using the notch and the side clips.
4. Install a hard drive or SSD and connect its data and power cables.
5. Carry out a final check before plugging the computer into the wall.

What are the key terms in computer assembly?

These are the words students must know before they start assembling.

• Power supply unit (PSU): the part that changes mains electricity into the low-voltage power the computer parts use.
• RAM: the temporary memory that holds the programs and data in use; its contents are lost when power goes off.
• Hard drive (HDD): a storage device that keeps data on spinning magnetic disks.
• SSD: a storage device that keeps data on flash memory chips and has no moving parts.
• SATA cable: the thin data cable that connects a drive to the motherboard.
• ESD (electrostatic discharge): a sudden flow of static electricity that can damage computer parts.
• Short circuit: electricity flowing along a wrong path, which can damage the computer.
• Drive bay: a metal shelf inside the case where a drive is fixed.

In what order do you assemble the parts?

In this lesson, the parts are installed in four stages: PSU, RAM, drive, then a final check.

How do you prepare to assemble a computer?

Preparation means setting up a clean, safe work area and grounding yourself before you touch any part.

1. Clear the area: use a flat wooden or plastic table. Never work on a rug or carpet, because it builds up static (ESD).
2. Organise your screws: keep them in a small bowl or magnetic tray. A lost screw inside the case can cause a short circuit.
3. Ground yourself: touch the metal part of the computer case, or wear an anti-static wrist strap.

How do you install the power supply unit (PSU)?

The PSU is installed first because it is usually the heaviest part and keeps the case stable.

1. Position it: find the large square hole at the top-back or bottom-back of the case. Slide the PSU into it.
2. Check the fan direction: do not block the PSU fan. It should face the vents in the case so air can flow.
3. Screw it in: line up the four screw holes on the back of the case with the PSU. Tighten firmly, but do not over-tighten, because you could strip the metal.

How do you install the RAM?

RAM is installed by opening the slot clips, matching the notch and pushing the stick straight down until the clips snap shut.

• Handling rule: hold the RAM by its edges.
• Do not touch the gold contacts: oil from your skin can cause a bad connection.

1. Open the clips: find the RAM slots on the motherboard. Push the plastic clips at the ends outward until they click open.
2. Find the notch: the bottom of the RAM has a small gap (the notch). The slot has a matching bump. If they do not line up, turn the RAM around.
3. Push down: push the RAM straight into the slot with firm pressure. The side clips snap shut on their own when it is deep enough.

• Technician’s tip: if you do not hear the click, the RAM is not seated properly and the computer will not start.

How do you install the hard drive (HDD) or SSD?

A drive is installed by sliding it into a bay, screwing it down and connecting a data cable and a power cable.

• Why it matters: the drive stores your files, so it must be fixed tightly to stop it vibrating.

1. Use the drive bay: slide the drive into one of the metal bays inside the case.
2. Secure it: line up the holes on the side of the drive with the holes in the bay. Use at least two screws on each side.
3. Connect the cables: a drive needs two cables, as shown below.

Cables a drive needs

How do you double-check your work?

The “Final Walkthrough” is a set of checks done before the computer is plugged into the wall.

• The shake test: gently shake the case. A rattle means a loose screw, which can cause a short circuit if it touches the motherboard. Find it and remove it.
• Cable management: make sure no wire touches the CPU fan. A stuck wire can stop the fan, and the CPU can overheat.
• The RAM check: look at the RAM once more. Both side clips must be fully closed.

What are the key points for each part?

This table sums up the one thing to remember for each part.

What mistakes should you avoid?

Most assembly faults come from a few simple mistakes.

Evaluation

1. Why should you keep screws in a small bowl or magnetic tray while assembling a computer?
2. State the three steps for installing RAM.
3. Name the two cables a hard drive needs and say where each one connects.
4. List the three checks in the “Final Walkthrough.”
5. In pairs, hold a RAM stick correctly, point out the notch and explain why the RAM cannot go in backwards.

Assignment

In your notebook, write out the three steps for installing the PSU in order. Then explain why the PSU fan must not be blocked.