Maintenance, Diagnosis & Troubleshooting
How do we work out what is wrong with a computer, step by step?
- State the 5-step troubleshooting cycle
- Apply it to two real faults (won't power on, no sound)
- Record findings in a troubleshooting log
Overview
Good sysadmins do not guess. They follow a repeatable cycle: gather facts, form a theory, test, fix, then document what happened. This week we practise that cycle on real (simulated) faults in the lab.
The 5-step troubleshooting cycle
Every fault, from a dead PC to a broken printer, can be worked through with the same five steps.
Five steps to follow — in order:
- 1. Identify the problem: What exactly is happening? What changed?
- 2. Establish a theory: Ask 'what could cause this?' — list likely causes.
- 3. Test the theory: Try the simplest test first (is it plugged in?).
- 4. Fix and verify: Apply the fix; confirm the fault is gone.
- 5. Document: Write what happened and how it was fixed — for next time.
Worked example — PC won't power on
Step 1 problem: press power, nothing happens. Step 2 theory: no power, faulty cable, dead PSU, unseated RAM. Step 3 test: check wall socket → try another cable → open case, reseat RAM. Step 4 fix: cable was loose; PC boots. Step 5 document: log the fault and fix.
Worked example — no sound
Check volume → check mute → check output device (headphones vs speakers) → check driver in Device Manager → test on another user account.
Station rotation — 3 simulated faults
- Rotate through 3 lab stations with pre-set faults.
- For each station, complete a troubleshooting log using the 5-step cycle.
- Compare logs with another group at the end.
- List the 5 troubleshooting steps in order.
Reveal answer
Identify · theory · test · fix and verify · document.
- Give three possible causes of 'PC will not power on'.
Reveal answer
No wall power, faulty cable, dead PSU, unseated RAM (any 3).
- Why is documentation the last step?
Reveal answer
So the next person can solve the same fault faster.
Write up one real fault you have seen at home (phone, TV, PC) using the 5-step cycle.