Hardware and Network Troubleshooting

What this domain actually tests

The biggest domain on the exam, at 29% — which genuinely surprises candidates who assume A+ is mostly about naming components. Nearly a third of Core 1 is diagnosis.

CompTIA's troubleshooting methodology, in order — and they test the sequence, explicitly:

1. Identify the problem
2. Establish a theory of probable cause (question the obvious)
3. Test the theory to determine the cause
4. Establish a plan of action and implement the solution
5. Verify full system functionality and implement preventive measures
6. Document findings, actions, and outcomes

The exam asks "what should the technician do NEXT?" and the answer is simply whichever step follows the one described in the scenario. Memorise it like a poem.

The traps

Two traps live in the order, and both cost marks:

• Documentation is LAST. Not first, not somewhere in the middle.
• Verification comes BEFORE documentation. If a scenario describes a fix that appears to have worked and asks what to do next, the answer is verify full system functionality — not "document it and close the ticket."

First-timers skip memorising this because it feels like common sense, and then lose the marks anyway. It is free.

The printer questions. Laser printing stages appear on nearly every exam, and candidates consistently arrive without having learned them because printers feel like the least interesting thing in IT.

The seven stages, in order: processing, charging, exposing, developing, transferring, fusing, cleaning.

Learn them. They are free marks and they are left on the table every single day.

Symptom-to-cause pattern matching. No POST with beep codes. A machine that powers on but shows nothing on screen. Thermal shutdown from a failed fan. A drive that clicks (mechanical failure — get the data off now). RAID array in a degraded state. Learn what each symptom points at.

Network troubleshooting tools, and which one answers which question: ping (is it reachable?), traceroute/tracert (where does the path die?), nslookup/dig (is DNS resolving?), ipconfig/ifconfig, and physically, a cable tester versus a toner probe (finding which cable is which in a bundle).

How to study it

Recite the six steps until they are automatic, then practise the "what next?" question format specifically — read a scenario, identify which step it stopped at, name the following one. That mechanical drill is worth an enormous amount for how little time it takes.

Then learn the seven printer stages. Yes, really. Watch a five-minute video of a laser printer's imaging process; a visual makes them stick far better than a list.

At 29% this is the largest block of marks on Core 1, and it is unusually rule-governed — sequences and symptom-matching rather than open-ended reasoning. That makes it very winnable.