Maintenance of Computer Hardware – SS1 Computer Hardware & GSM Repair Lesson Note (Third Term)

Computer hardware maintenance is the regular care given to a computer so that it stays healthy and works for a long time.

Behavioural objectives

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

1. State why dust, heat and humidity are a danger to computer hardware.
2. Clean a computer safely using a blower, a soft brush and a microfibre cloth.
3. Name the three parts that keep a computer cool: heat sink, fan and thermal paste.
4. Describe the three main upgrades: RAM, SSD and graphics card.
5. Explain how to care for a laptop and follow a maintenance schedule.

Why is prevention important?

Prevention is important because it is cheaper to stop damage than to repair a computer after it fails.

• Heat: too much heat makes parts wear out early and makes the computer slow or shut down.
• Dust: dust collects on fans, vents and boards and traps heat inside the case.
• Humidity: damp air can cause rust and corrosion on metal contacts and circuits.
• Power problems: sudden surges and power cuts can damage the power supply and other parts.

What are the types of maintenance?

There are two types of hardware maintenance: preventive maintenance and corrective maintenance.

• Preventive maintenance: regular care done before anything breaks, such as cleaning and checking fans.
• Corrective maintenance: repair work done after a fault has appeared, such as replacing a dead fan.

This lesson focuses on preventive maintenance.

How does dust harm a computer?

Dust harms a computer by acting like a blanket that traps heat around the parts.

• When the CPU (the brain of the computer) gets too hot, the computer slows down to protect itself.
• If the heat stays high, the computer may shut down suddenly or the parts may be damaged.

How do you clean a computer safely?

You clean a computer safely by switching it off first and using only dry, soft cleaning tools.

What tools are used for cleaning?

• The blower: a can of compressed air or an electric blower pushes dust out of the vents and fans.
• Soft brush: a clean, dry paintbrush gently sweeps dust off the motherboard and other parts.
• Microfibre cloth: a soft cloth for the screen and outer case. A rough towel will scratch the screen.

What are the steps for cleaning?

1. Shut down the computer and unplug it from the power. Remove the laptop battery if it can be removed.
2. Take the computer outdoors or to an open, airy place, so the dust does not settle in the room.
3. Blow dust out of the vents and fans in short bursts. Hold the fan blades still so they do not spin too fast.
4. Sweep dust off the motherboard gently with the dry brush.
5. Wipe the screen and outer case with the microfibre cloth.

Rule number one: Never spray water or liquid cleaner directly onto the computer. Spray it on the cloth first!

How does a computer stay cool?

A computer stays cool through its cooling system, which has three main parts: the heat sink, the fan and the thermal paste.

1. Heat sink: the metal “fins” sitting on top of the CPU. They pull heat away from the chip.
2. Fan: it blows hot air out of the case. A fan that sounds like a jet engine or grinds needs cleaning or replacing.
3. Thermal paste: a grey “cream” between the CPU and the heat sink. Over time it dries and hardens, and then it stops working.

Maintenance task: About every 2 years, a trained technician should clean off the old paste and apply a fresh, pea-sized drop of new thermal paste.

Which upgrades give an old computer a “new life”?

An upgrade is the replacement or addition of a part to make an old computer work better.

There are three main upgrades: RAM, SSD and graphics card.

RAM upgrade

• Problem it solves: the computer “hangs” when you open many programmes or browser tabs.
• What to do: add more RAM. It is the easiest part to install because it clicks into its slot.
• Check first: the new RAM must be the type the motherboard supports.

SSD upgrade

• SSD: a Solid State Drive, a storage drive with no moving parts.
• Problem it solves: the computer takes a very long time to start or open files.
• What to do: replace the old hard disk drive with an SSD. The computer starts and opens programmes much faster.

Graphics card upgrade

• Graphics card: a part that handles pictures and video for the screen.
• Problem it solves: heavy video editing or gaming runs poorly.
• What to do: add a dedicated graphics card so the computer handles heavy pictures and videos.

How should you care for a laptop?

A laptop needs extra care because all its parts are packed into a small space.

• Ventilation: never use a laptop on a bed, pillow or carpet. Soft surfaces block the vents at the bottom, and trapped heat can damage the motherboard. Use a hard table or a laptop stand.
• Battery care: do not leave the laptop plugged in all day and night. Use it on battery sometimes, because a battery kept at 100% all its life wears out faster.
• The keyboard: do not eat crumbly food such as biscuits over the laptop. Crumbs get stuck under the keys and are hard to remove.
• Carrying: shut down or put the laptop to sleep and carry it in a padded bag.

How do you protect a computer from power problems?

You protect a computer from power problems by placing a protective device between the computer and the socket.

• Surge protector: a power strip that blocks sudden high voltage from reaching the computer.
• Voltage stabiliser: a device that keeps the voltage steady when the supply goes up and down.
• UPS (Uninterruptible Power Supply): a battery unit that keeps a desktop running for a short time after a power cut, so you can save your work and shut down properly.

What is the maintenance schedule?

A maintenance schedule is a timetable that tells you which care task to do and how often.

• Laptops: let a trained technician open the case, because laptops are harder to take apart.
• Record keeping: write the date of each task in a log book, so you know when the next one is due.

Class discussion

1. Why does a computer get louder (the fan spins faster) when you start playing a heavy video game?
2. If a computer is very slow but has plenty of space for photos, which component should we upgrade first? (Hint: think about the upgrades section.)

Evaluation

1. Name three things that can be used to clean a computer safely.
2. Why should you spray liquid cleaner on the cloth and not on the computer?
3. What does thermal paste do, and how often should it be replaced?
4. Why should a laptop not be used on a bed or a pillow?
5. State the difference between preventive and corrective maintenance.

Assignment

Write out the maintenance schedule in your notebook, giving the task for each of the four time periods. Then describe in your own words the three main upgrades for an old computer.