Computers sometimes stop working properly – the screen stays black, the printer won’t print, or the laptop won’t switch on. Many of these problems have simple causes you can fix yourself. Troubleshooting means finding the cause of a problem step by step and fixing it.

This builds on Inside the Computer, where you learnt the main hardware components.

Build on what you learned in Forms 1–3

These Lower School ICT posts cover the basics of this topic:

• Physical Care for Computer Systems – looking after equipment so problems happen less often
• Computer Hazards – staying safe around cables, power and equipment
• Hardware Specifications – Computer Ports – the ports where cables plug in

In this post:

• A simple troubleshooting procedure
• Cable problems
• Monitor problems
• Printer problems
• Battery problems

A simple troubleshooting procedure

1. Identify the problem – what exactly is happening? Any error messages or lights?
2. Check the obvious first – is it plugged in and switched on?
3. Try one fix at a time and test after each change.
4. Write down what you tried and what worked.
5. Get help from a technician if the simple fixes don’t work. Never open a power supply or monitor.

Video: How to Troubleshoot – CompTIA A+ 220-1001 – 5.1 – https://www.youtube.com/watch?v=3PDn-Zteckc

Cable problems

• Symptoms: device not detected, no picture, no power, intermittent connection.
• Fixes:
  • check that power and data cables are firmly plugged in at both ends
  • reseat (unplug and plug back in) loose cables
  • try a different cable or port
  • check for bent pins or damaged wires

Image source: File:Male VGA connector.jpg

Monitor problems

• No picture: check that the monitor is switched on (power light), the cable is connected, and the correct input (HDMI/VGA) is selected.
• Too dark or strange colours: the monitor controls (brightness, contrast, colour) may be improperly adjusted – use the monitor’s menu buttons or reset to factory settings.
• Flickering: check the cable; adjust the refresh rate in display settings.

Video: Troubleshooting Video and Display Issues – CompTIA A+ 220-1001 – 5.4 – https://www.youtube.com/watch?v=mR-Ia1WA7RE

Printer problems

• Nothing prints: check power, cable/Wi-Fi connection, and that the correct printer is selected.
• Faded or streaky printing: the ink or toner is low – change the printer cartridge.
• Paper jam: switch off, gently remove the jammed paper in the direction it travels, and don’t overload the tray.

Image source: File:HP Inkjet Black Print Cartridge 21.jpg

Video: Troubleshooting Printers – CompTIA A+ 220-1001 – 5.6 – https://www.youtube.com/watch?v=DD1Cgpv7aWc

Battery problems

• Laptop won’t switch on without the charger: the battery may be dead or loose – reseat it (if removable) and charge it.
• Battery drains very fast: an old battery holds less charge and may need replacing.
• Remote control or wireless mouse not working: replace the small batteries.
• Wrong date and time every time the PC starts: the small CMOS battery on the motherboard may be dead.

Image source: File:Laptop PC Battery Removed.jpg

Video: Troubleshooting Common Hardware Problems – CompTIA A+ 220-1001 – 5.2 – https://www.youtube.com/watch?v=p4VxERfTHgU

More troubleshooting videos are in Videos: Troubleshooting Hardware.

Notice that this fault finder is really a flowchart made of decisions – you will use the same idea when you draw flowcharts in Problem-Solving and Program Design.

Paper 1 practice (multiple choice)

Choose the best answer for each question. Try them all before you check.

1. A monitor shows no picture, but its power light is on. What should be checked FIRST?
(A) The printer cartridge
(B) The video cable connection
(C) The CMOS battery
(D) The keyboard

2. Printing has become faint and streaky. The MOST likely solution is to
(A) replace the monitor
(B) change the printer cartridge
(C) reinstall the operating system
(D) replace the mouse

3. A laptop works only when plugged in. The MOST likely problem is
(A) a dead or loose battery
(B) a loose VGA cable
(C) low ink
(D) an incorrect monitor setting

4. Which should be done FIRST when troubleshooting?
(A) Open the power supply
(B) Buy a new computer
(C) Check that the device is plugged in and switched on
(D) Reinstall all software

5. The screen picture is very dark. Which is the BEST action?
(A) Adjust the brightness/contrast controls
(B) Change the printer cartridge
(C) Replace the hard disk
(D) Remove the battery

Show answers

1. B
2. B
3. A
4. C
5. A

Paper 2 practice (structured question)

Jamal reports three problems in the school computer lab.

(a) The mouse on Computer 3 does not respond. Suggest TWO steps Jamal could take to fix the problem. (2 marks)

(b) The printer prints pages with faded text. State the likely cause and the solution. (2 marks)

(c) Computer 5’s monitor screen is black but the computer is running. Describe THREE checks Jamal should make, in a sensible order. (3 marks)

(d) Explain why it is good practice to change only one thing at a time when troubleshooting. (1 mark)

Total: 8 marks

Show answers

(a) Any two (1 each):
• check/reseat the mouse cable/USB plug
• try another USB port
• replace batteries (if wireless)
• test the mouse on another computer

(b) Low ink/toner (1); replace the printer cartridge (1).

(c) Any three in a logical order (1 each):
• check the monitor is switched on/power light
• check the power cable
• check the video cable at both ends
• check the correct input is selected
• adjust brightness/contrast

(d) So you know which change fixed the problem (and don’t create new problems) (1).

Next: Data vs Information: Sources of Data and Types of Documents

Syllabus link: This post is relevant to the CSEC® Information Technology Syllabus (CXC 30/G/SYLL 17), Section 1: Computer Fundamentals and Information Processing, Specific Objective 10 (“troubleshoot basic computer hardware problems”).

Attributions to media used in this post:

• Male VGA connector.jpg – Swift.Hg – CC BY-SA 3.0 (via Wikimedia Commons)
• HP Inkjet Black Print Cartridge 21.jpg – MarcoTangerino – Public domain (via Wikimedia Commons)
• Laptop PC Battery Removed.jpg – Intel Free Press – CC BY-SA 2.0 (via Wikimedia Commons)

© 2026 Vedesh Kungebeharry. All rights reserved.