mediumMultiple Choice
220-1201 Power supply troubleshooting Practice Question
A customer complains that their computer will not turn on. The power supply fan does not spin, and the motherboard LED is off. The technician tests the power supply with a multimeter and gets 0V on all pins. What should the technician do next?
⚠ Common exam trap
220-1201 often tests troubleshooting order — candidates jump to replacing components (PSU, motherboard) before verifying the simplest external cause (wall outlet), missing that 0V on all pins points to an input power problem first.
Answer choices
Why each option matters
Answer the question above first, then reveal the full breakdown to understand why each option is right or wrong.
Correct answer & explanation
✓
Check the wall outlet with a voltage tester.
The technician measured 0V on all power supply pins with a multimeter, which indicates the PSU is not receiving power or is completely dead. Before replacing the PSU, the next logical step is to verify the power source — checking the wall outlet with a voltage tester confirms whether the outlet is supplying power. If the outlet is dead, replacing the PSU would not solve the problem.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
- ✗
Replace the motherboard.
Why it's wrong here
Replacing the motherboard is a premature and costly step when a computer fails to turn on, as it bypasses critical initial diagnostics. The motherboard is a downstream component that requires power from the power supply unit (PSU), which in turn receives power from the wall outlet. Troubleshooting dictates verifying the power source and the PSU's functionality first, as these are far more common failure points for a 'no power' symptom than the motherboard itself.
- ✗
Reseat the 24-pin power connector.
Why it's wrong here
Reseating the 24-pin power connector is generally not the initial troubleshooting step for a computer that exhibits no power whatsoever. If the computer 'will not turn on,' it implies a complete lack of power, suggesting a more fundamental issue with the power source or the power supply unit (PSU) itself. A loose 24-pin connector might cause intermittent power or failure to POST, but it's less likely to be the root cause of a total power outage compared to external power issues.
- ✗
Replace the power supply with a known-good unit.
Why it's wrong here
Replacing the power supply with a known-good unit, while a valid step if the PSU is suspected, is not the immediate next action for a 'no power' complaint. Before incurring the cost and effort of swapping components, it is essential to first confirm that the existing PSU is even receiving power from the wall outlet. Skipping this crucial diagnostic step can lead to unnecessary component replacement if the actual problem lies with the external power source rather than the PSU itself.
- ✓
Check the wall outlet with a voltage tester.
Why this is correct
Checking the wall outlet with a voltage tester is the correct and most logical first step when a computer fails to turn on. This action directly verifies the primary power source, confirming whether AC voltage is present and sufficient at the point of connection. This diagnostic step quickly rules out external issues such as a tripped circuit breaker, a faulty outlet, or a problem with the building's electrical wiring, thereby isolating the problem to either the external power source or the computer's internal power components.
Go deeper
Related to this question
About these practice questions
One of 871 original 220-1201 practice questions on Courseiva, each with a full explanation and wrong-answer analysis — not exam dumps or protected exam content. Learn why practice questions differ from exam dumps →
JA
Written and reviewed by Johnson Ajibi, MSc IT Security
Senior Network & Security Engineer · founder of Courseiva
Last reviewed September 2026 · checked against the official CompTIA exam blueprint
This 220-1201 practice question is part of Courseiva's free CompTIA certification practice question bank. Courseiva provides original exam-style practice questions with explanations, topic-based practice, mock exams, readiness tracking, and study analytics to help learners prepare for the 220-1201 exam.