Repair and Maintenance

Repair is the restoration work performed when an asset is broken, damaged, or non-functional.

Maintenance refers to regular activities and corrective or preventive repairs performed on equipment to prevent damage and extend its life expectancy.

Preventive Maintenance of the System

Preventive Maintenance is the regular and systematic inspection, cleaning, and replacement of worn parts, materials, and systems.

Effective preventive maintenance reduces failures of parts, materials, and systems while keeping hardware and software in good working condition.

Computer Preventive Maintenance

Some important computer preventive maintenance activities are:

1. Clean computer equipment regularly.
2. Download the latest drivers for hardware.
3. Download the latest updates for computer software.
4. Make sure the latest antivirus protection is installed and updated.
5. Run disk utilities such as Defrag and ScanDisk on the hard drive.
6. Remove unused programs and unnecessary files.
7. Restart the computer every few weeks if it is not normally shut down, except in the case of important systems such as servers.

Fixing Wireless Network Connection Issues

The following steps can be used to fix wireless network problems.

Make Sure Wi-Fi is Turned On

Select the No Internet Connection icon on the right side of the taskbar.

Make sure Wi-Fi is turned on.

If Wi-Fi is off, turn it on.

Also make sure that Airplane Mode is turned off.

Check Available Wi-Fi Networks

Select Manage Wi-Fi Connections from the Wi-Fi quick settings.

Check whether a known and trusted Wi-Fi network appears in the list.

If it does:

1. Select the Wi-Fi network.
2. Try to connect to it.
3. If it already shows as connected, disconnect it.
4. Wait for a moment.
5. Connect again.

Try a Different Wi-Fi Frequency Band

Many Wi-Fi routers broadcast on two frequency bands:

• 2.4 GHz
• 5 GHz

If both networks are available, try connecting to the other frequency band.

Check the Physical Wi-Fi Switch

Make sure the physical Wi-Fi switch on the laptop is turned on.

Run the Network Troubleshooter

The Network Troubleshooter can help diagnose and fix common connection problems.

Steps to Run the Network Troubleshooter

1. Select Start > Settings > System > Troubleshoot > Other Troubleshooters.
2. Under Other, select Network Adapter > Run.
3. Follow the steps displayed by the troubleshooter.

Restarting the modem and wireless router may also help create a new connection with the Internet Service Provider (ISP).

When the modem and router are restarted, all users connected to the Wi-Fi network will be temporarily disconnected.

Power Source and Power Protection

Computer components use Direct Current (DC) power.

However, electricity supplied by the power company is generally Alternating Current (AC).

The Power Supply Unit (PSU) converts AC power from the mains into low-voltage regulated DC power required by the computer’s internal components.

Power protection devices can help prevent:

• Hardware damage
• Data loss
• Problems caused by voltage fluctuations
• Problems caused by power outages

Voltage spikes can damage computer equipment, while sudden power outages can result in data loss.

Types of Power Protection Devices

The following power protection devices are discussed:

1. Surge Suppressors
2. Phone-Line Surge Protectors
3. Line Conditioners
4. Standby Power Supplies (SPS)
5. Uninterruptible Power Supplies (UPS)

Surge Suppressors

A Surge Suppressor, also called a surge protector, is a device placed between the computer system and the power line.

It can absorb high-voltage transients caused by:

• Nearby lightning strikes
• Electrical equipment
• Power-line disturbances

Surge protectors provide protection against certain types of power problems, although their protection may be limited.

Phone-Line Surge Protectors

In addition to power-line protection, telephone lines connected to a computer system should also be protected.

If a modem or fax card is connected to a telephone system, power surges or spikes transmitted through the phone line can damage the computer system.

Telephone lines can be vulnerable to lightning strikes, which may damage:

• Modems
• Connected computer equipment

Line Conditioners

Power problems can occur even when there is no high-voltage spike.

A brownout occurs when the voltage drops below the level required to keep the system operating.

Other electrical problems may include:

• Radio-frequency interference
• Electrical noise caused by motors
• Noise caused by inductive loads

A line conditioner helps manage such incoming power problems.

Standby Power Supplies (SPS)

A Standby Power Supply (SPS) is a self-sufficient or backup power source.

Such systems may use batteries or other power sources to provide electricity when the main power supply is unavailable.

Uninterruptible Power Supply (UPS)

An Uninterruptible Power Supply (UPS) provides backup power during:

• Electrical outages
• Voltage fluctuations

A UPS helps keep computers and other electronic devices operating long enough to save work and safely shut down the system.

A UPS commonly contains a battery that activates when the main power source fails.

Many UPS units also include surge protection.

UPS systems help prevent:

• Data loss
• Hardware damage
• Unexpected shutdowns

They are especially useful in places where continuous power is important, such as:

• Data centres
• Hospitals
• Offices

Failure or Improper Operation of Video Cards

A Video Card, also called a Graphics Card, generates the video signal sent to a computer display.

It may be:

• Integrated into the motherboard
• Installed as a separate expansion card
• Integrated into a display system

Other names for a video card include:

• Graphics Card
• Display Card
• Graphics Adapter
• GPU
• VGA Card
• Video Adapter
• Display Adapter

How to Recognize a Dying Video Card

Common signs of a failing video card include:

1. Programs frequently stutter or slow down.
2. Crashes occur during graphics-intensive tasks.
3. Unexpected graphical errors appear.
4. The card becomes extremely hot while performing tasks it previously handled normally.

Causes of Video Card Failure

Possible causes include:

1. Dust buildup on the video card.
2. Low or defective RAM.
3. Incorrectly installed graphics card.
4. Bad motherboard connection.
5. Faulty Power Supply Unit (PSU).
6. Blocked ventilation outlets.
7. Poor ventilation.
8. Excessive heat.
9. Physical damage caused by dropping the computer or laptop.

Consequences of Video Card Problems

Video card problems can affect the performance and usability of a computer.

Some common problems and troubleshooting methods are described below.

Loose Connection

A loose graphics card connection may cause:

• Screen flickering
• Black screen
• Loss of video output

Troubleshooting

1. Power down the computer.
2. Open the computer case.
3. Check whether the video card is properly seated.
4. Carefully reinsert the card if necessary.

Swapping Graphics Card Slot

If the video card does not work properly in its current slot, the motherboard slot itself may be faulty.

Troubleshooting

Move the video card to another compatible slot.

This helps identify whether the issue is with:

• The graphics card
• The motherboard slot

Checking the PC Monitor

A faulty monitor may sometimes appear to be a graphics card problem.

Troubleshooting

1. Connect the monitor to another computer.
2. Or connect a different monitor to the current computer.
3. Check whether the problem remains.

Testing Another Graphics Card

A faulty graphics card may cause:

• No display
• Graphical errors

Troubleshooting

Install a known working graphics card.

If the problem disappears, the original graphics card may be faulty.

Checking Sound Drivers

Graphics card problems may sometimes affect audio, especially when audio is transmitted through HDMI.

Troubleshooting

1. Check whether sound drivers are updated.
2. Check operating system sound settings.
3. Make sure the correct audio output device is selected.

Checking Device Status of Graphics Card

The operating system may report:

• Driver conflicts
• Hardware failures
• Other graphics card errors

Troubleshooting

Open Device Manager and check the graphics card status.

Look for:

• Error messages
• Warning symbols
• Driver problems

Update or reinstall the drivers if necessary.

How to Fix Video Card Problems

Common methods for fixing video card problems are described below.

Upgrade Video Card

If the graphics card is outdated or not powerful enough, it can be replaced with a newer model.

Steps

1. Research and purchase a compatible graphics card.
2. Power down the computer.
3. Open the computer case.
4. Remove the old graphics card.
5. Insert the new graphics card into the correct slot.
6. Connect the required power cables.
7. Start the computer.
8. Install the latest graphics drivers.

Disable and Enable the Device

Temporarily disabling and enabling the video card may solve minor problems.

Steps

1. Open Device Manager.
2. Find the graphics card under Display Adapters.
3. Right-click the graphics card.
4. Select Disable Device.
5. Wait for a few seconds.
6. Right-click the device again.
7. Select Enable Device.

Uninstall and Reinstall Drivers

Corrupted or outdated drivers may cause graphics card problems.

Steps

1. Open Device Manager.
2. Locate the graphics card.
3. Right-click it.
4. Select Uninstall Device.
5. Follow the instructions.
6. Restart the computer.
7. Download the latest driver from the manufacturer’s website.
8. Install the new driver.
9. Restart the computer again.

Cool and Clean the Video Card

Overheating may cause the graphics card to malfunction.

Steps

1. Power down and unplug the computer.
2. Open the computer case.
3. Carefully remove the graphics card.
4. Use compressed air to remove dust.
5. Clean the heatsink.
6. Check whether cooling fans work properly.
7. Reinstall the graphics card.
8. Ensure proper airflow inside the computer case.

Replace Video Card

If the video card is permanently faulty, replacement may be necessary.

Steps

1. Purchase a compatible graphics card.
2. Shut down the computer.
3. Open the case.
4. Remove the faulty card.
5. Install the new card.
6. Connect necessary power cables.
7. Start the computer.
8. Install the latest drivers.

Image Quality Problems in Monitor

Image quality problems may appear in different forms.

These may include:

• Blurry image
• Pixelated image
• Incorrect resolution
• Incorrect scaling
• Incorrect aspect ratio
• Stretched image
• Squashed image
• Inconsistent colours
• Incorrect brightness

Resolution problems may occur when the monitor’s native resolution does not match the computer’s display settings.

Image quality may also be affected by:

• Physical screen damage
• Incorrect settings
• Software problems
• Graphics driver problems

Steps to Solve Monitor Image Quality Problems

1. Check Physical Connections

Make sure all cables are properly connected.

Examples include:

• HDMI
• DisplayPort
• VGA

Try another cable or port if necessary.

2. Set Native Resolution

Set the monitor to its recommended native resolution.

In Windows:

Right-click Desktop > Display Settings

3. Adjust Scaling and Layout

Check the scaling and layout settings.

Incorrect scaling can cause content to appear too large, too small, stretched, or distorted.

4. Update Graphics Drivers

Outdated or corrupted graphics drivers may cause display problems.

Download the latest drivers from the graphics card manufacturer.

Examples include:

• NVIDIA
• AMD
• Intel

5. Calibrate the Display

Use display calibration tools to adjust:

• Brightness
• Contrast
• Colour

6. Check for Software Issues

Some third-party software may interfere with display settings.

Disable or uninstall software that may be affecting display performance.

7. Test with Different Hardware

Connect the monitor to another computer or device.

This can help determine whether the problem is with:

• The monitor
• The original computer

8. Factory Reset

If the problem continues, perform a factory reset through the monitor’s On-Screen Display (OSD) menu.

9. Professional Inspection

If none of the troubleshooting steps work, the monitor may have a hardware problem.

Contact the manufacturer or a professional technician.

Input and Output Device Connection Issues

Input and output device connection problems can usually be diagnosed using systematic troubleshooting.

Check Physical Connections

Make sure all cables are connected to the correct ports.

Try:

• Disconnecting and reconnecting cables
• Checking the power source
• Checking external power adapters

Device Drivers

Outdated or missing drivers may cause devices to malfunction.

Possible solutions include:

1. Download the latest driver from the manufacturer’s website.
2. Reinstall the device driver.
3. Restart the computer.

Device Manager Check

Open Device Manager and look for:

• Yellow warning triangle
• Red X
• Other warning symbols

These may indicate a device problem.

Right-click the affected device and select Update Driver.

Compatibility Issues

Make sure the device is compatible with the operating system.

Check the manufacturer’s website for compatibility information.

Recently installed software may also interfere with the device.

Try disabling or uninstalling recently installed software.

Check for Interference

Wireless devices may experience interference from:

• Other wireless devices
• Wi-Fi networks
• Physical obstructions

For Bluetooth devices:

1. Make sure Bluetooth is enabled.
2. Make sure the device is paired correctly.
3. Keep the device within range.

Test on Another Computer

Connect the device to another computer.

If it works correctly, the problem may be with the original computer.

If it does not work, the device itself may be faulty.

System Updates

Keep the operating system updated.

Updates may fix:

• Bugs
• Compatibility problems
• Device-related errors

Also check whether the device manufacturer provides firmware updates.

Specific Device Troubleshooting

Possible troubleshooting steps include:

• Try another USB port.
• Check wireless device batteries.
• Check display input source.
• Try another cable.
• Check network connection for network printers.
• Check printer paper.
• Check ink or toner.
• Run the printer troubleshooter.

Reset Devices

Restarting the device and computer may solve temporary problems.

Some devices also provide a factory reset option.

Refer to the device manual for instructions.

Seek Professional Help

If the device still does not work after troubleshooting, contact:

• Manufacturer technical support
• Local computer technician

Processor Power and Voltage Level

Processor power and voltage are important factors in computer performance and stability.

The CPU requires a stable power supply to function correctly.

Modern processors generally operate at relatively low voltage levels.

According to the notes, these voltage levels may range from approximately:

0.7V to 1.4V

The exact value depends on:

• Processor model
• Operating conditions
• Workload

The motherboard’s Voltage Regulator Module (VRM) converts higher PSU voltage into the lower voltage required by the CPU.

Stable voltage regulation is important because incorrect voltage can result in:

• System instability
• System crashes
• Reduced processor lifespan

Processors can also dynamically adjust power consumption based on workload.

The notes mention technologies such as:

• Intel SpeedStep
• AMD Cool’n’Quiet

These technologies help balance:

• Performance
• Power efficiency
• Heat generation

Overclocking may involve increasing voltage, but excessive voltage or heat can damage the processor.

Introduction to Processor Cooling

Processor cooling is important for maintaining:

• Performance
• Stability
• Processor lifespan

Processors generate heat while performing calculations.

This heat must be removed efficiently to prevent overheating.

Different cooling methods include:

1. Heat Sink
2. Fan
3. Thermal Pad or Thermal Paste
4. Liquid Cooling
5. Vapor Cooling
6. Heat Pipe
7. Passive Cooling

Heat Sink

A Heat Sink is a passive cooling device.

It absorbs heat from the processor and releases it into the surrounding air.

Heat sinks are usually made from materials with high thermal conductivity, such as:

• Aluminum
• Copper

They often contain fins to increase surface area and improve heat dissipation.

Fan

A Fan is an active cooling device.

It is often used together with a heat sink.

The fan moves air over the heat sink and helps remove heat from the processor.

A heat sink and fan combination is commonly called an air cooler.

Thermal Pad or Thermal Paste

Thermal pads and thermal paste improve thermal conductivity between the processor and heat sink.

They fill microscopic gaps between surfaces.

This improves heat transfer.

Thermal Paste:

• Usually offers better thermal performance.
• Requires careful application.

Thermal Pad:

• Easier to install.
• May provide slightly lower thermal performance.

Liquid Cooling

Liquid cooling uses coolant to carry heat away from the processor.

The coolant moves through a closed loop.

It passes through:

1. Water block attached to the CPU
2. Tubes
3. Radiator

Fans on the radiator remove heat from the coolant.

Liquid cooling is effective for:

• High-performance processors
• Overclocked systems

Vapor Cooling

Vapor cooling uses phase-change materials.

The liquid absorbs heat and changes into vapor.

The vapor then moves away from the heat source, cools, and changes back into liquid.

Vapor chambers are often used in:

• High-end heat sinks
• Graphics card coolers

Heat Pipe

A Heat Pipe is a sealed tube containing liquid.

The liquid:

1. Vaporizes when heated.
2. Moves heat away from the processor.
3. Condenses when cooled.

Heat pipes efficiently transfer heat to a heat sink or radiator.

Passive Cooling

Passive Cooling uses natural convection and radiation to remove heat.

It does not use moving parts such as fans.

Passive cooling generally uses large heat sinks.

Advantages include:

• Silent operation
• No power required

However, passive cooling is generally less effective than active cooling.

It is more suitable for low-power systems.

Cooling and Ventilation

Proper cooling and ventilation are important because computer components such as the CPU and GPU generate heat.

Several methods can improve cooling.

Keep the System Away from Vents and Windows

Avoid placing the computer:

• In direct sunlight
• Near excessive heat
• Near cold drafts

Direct sunlight can cause overheating.

Cold air may contribute to condensation.

Give the System Some Breathing Room

Make sure there is enough space around the computer for proper airflow.

Avoid placing the computer:

• Against walls
• In tightly enclosed spaces

Close the System Case

Keeping the computer case closed helps maintain controlled airflow.

It can also reduce the amount of dust entering the system.

Clean Fans

Dust can reduce airflow and cooling efficiency.

Regularly clean fans using:

• Compressed air
• Soft brush

Upgrade CPU Fans

A more powerful or efficient CPU fan can improve cooling performance.

This may be useful when the computer experiences overheating.

Add a Case Fan

Additional case fans can improve airflow inside the computer case.

Fans can direct cool air toward components such as:

• CPU
• GPU
• Motherboard

Add More Cooling Fans

High-performance or overclocked systems may require multiple fans.

Fans may be installed on:

• Front panel
• Rear panel
• Top panel
• Side panel

Get a Water Cooling Kit

A water cooling kit uses liquid to transfer heat from the CPU or GPU to a radiator.

Water cooling can provide better thermal performance than air cooling.

It is useful for:

• High-performance systems
• Overclocked systems

However, water cooling generally requires more setup and maintenance.

Virus Background

A Computer Virus is a type of malicious software, also called malware.

It is designed to replicate itself and spread from one computer to another.

Viruses may harm:

• Files
• Applications
• Operating systems
• Computer performance

Different viruses can be classified according to how they operate and spread.

Types of Computer Viruses

The notes discuss the following types:

1. File Virus
2. Boot Sector Virus
3. Macro Virus
4. Source Code Virus
5. Encrypted Virus
6. Stealth Virus
7. Tunneling Virus
8. Multipartite Virus
9. Browser Hijacker
10. Resident Virus

File Virus

A File Virus attaches itself to executable files.

Examples include:

• .exe
• .dll

When an infected file is executed, the virus code runs.

It may then infect other files.

Boot Sector Virus

A Boot Sector Virus infects the boot sector of storage devices.

Examples include:

• Hard drives
• USB drives

It may spread when an infected bootable device is accessed during system startup.

Boot sector viruses may interfere with the boot process and may prevent the system from booting.

Macro Virus

A Macro Virus infects documents and spreadsheets containing macros.

These may include files created using:

• Microsoft Word
• Microsoft Excel

When an infected document is opened, the malicious macro may execute and spread.

Source Code Virus

A Source Code Virus infects programming source-code files.

When infected source code is compiled, the resulting executable may also become infected.

Encrypted Virus

An Encrypted Virus uses encryption to hide its code.

It may decrypt itself before execution.

This can make detection more difficult.

Stealth Virus

A Stealth Virus attempts to hide itself from antivirus software and security systems.

It may manipulate system calls or file structures to avoid detection.

Tunneling Virus

A Tunneling Virus uses methods to bypass security controls.

It may attempt to bypass:

• Firewalls
• Intrusion detection systems

Multipartite Virus

A Multipartite Virus combines characteristics of multiple virus types.

For example, it may infect:

• Files
• Boot sectors

This can make it more difficult to detect and remove.

Browser Hijacker

A Browser Hijacker is malware that modifies browser settings without the user’s permission.

It may change:

• Homepage
• Search engine
• Browser extensions

It may also:

• Redirect users to unwanted websites
• Display unwanted advertisements

Resident Virus

A Resident Virus remains active in the computer’s memory or RAM.

It can infect files when they are:

• Opened
• Accessed
• Executed

Virus Detection, Protection and Prevention Techniques

There are several ways to reduce the risk of virus infection.

Virus Detection and Prevention Tips

1. Scan external disks or storage devices before opening files.
2. Never open email attachments from unknown or unreliable sources.
3. Verify unexpected attachments even if they appear to come from someone you know.
4. Avoid suspicious email attachments.
5. Delete spam and chain emails.
6. Do not respond to or forward suspicious messages.
7. Never download files from unknown sources.
8. Use caution when downloading files from the internet.
9. Update antivirus software regularly.
10. Make regular backups of important files and folders.

Protect Yourself and Your Computer

Be cautious when:

• Opening email attachments
• Clicking unknown links
• Downloading files
• Installing software

Avoid downloading software from untrusted websites or peer-to-peer networks.

Enable browser security features such as:

• Pop-up blockers
• Security settings

Be aware of social engineering methods used to trick users into revealing information or installing malware.

Keep Your Device Secure

Keep the following updated:

• Operating system
• Applications
• Firmware

Install security patches regularly.

Enable automatic updates where possible.

Disable unnecessary services and features to reduce security risks.

Use Antivirus Software

Install reputable antivirus software.

Keep it updated with the latest virus definitions.

Perform regular scans to detect and remove malware.

Use Antispyware Software

Antispyware software can help detect and remove:

• Spyware
• Adware
• Potentially unwanted programs

Keep antispyware software updated.

Firewalls

Enable and configure a firewall to control:

• Incoming network traffic
• Outgoing network traffic

The notes recommend using:

• Hardware firewall from a router
• Software firewall on the computer

Use Strong Passwords

Use passwords containing a combination of:

• Letters
• Numbers
• Special characters

Avoid easily guessed passwords such as:

• 123456
• password

A password manager can also be used to generate and store strong passwords.

Use Stronger Authentication

Enable Multi-Factor Authentication (MFA) whenever possible.

MFA requires more than one authentication method.

For example:

• Password
• Verification code sent to a mobile device

Protect Your Private Information

Be careful when sharing personal or sensitive information online.

Review privacy settings on:

• Websites
• Social media accounts

Control who can access your information.

Be Careful What You Click

Avoid clicking suspicious links or downloading unknown files.

These may contain:

• Malware
• Phishing attempts

Shop Safely

Only make online purchases from trusted websites.

Look for secure websites using HTTPS.

Avoid entering sensitive information on:

• Public Wi-Fi
• Unsecured websites

Be Careful What You Share

Be careful about information shared on:

• Social media
• Online forums

Oversharing may increase risks such as identity theft.

Responding to Data Breaches

Stay informed about security incidents affecting your accounts or personal information.

If a data breach occurs:

1. Change passwords.
2. Monitor accounts.
3. Look for suspicious activity.

Parents Take Control

Children should be educated about:

• Online safety
• Responsible internet use
• Risks of unknown links
• Risks of sharing personal information

Parental control features can also be used to monitor and limit access to inappropriate online content.