The answer is a failed motherboard power-on circuit. When a PC has no power and the PSU fan doesn’t spin, the motherboard’s power-on circuit is responsible for signaling the power supply to start; if this circuit is shorted or damaged, it can block the PSU from receiving the “power good” signal, even if the PSU itself is functional. On the CompTIA A+ Core 1 220-1201 exam, this scenario tests your ability to isolate a motherboard-level failure from a PSU failure—a common trap is immediately blaming the power supply when the motherboard’s power LED is off, which actually points to a lack of standby voltage being properly routed. Remember that the CMOS battery only affects BIOS retention, not the power-on sequence, so a dead battery won’t stop the fan from spinning. A useful memory tip: “No spin, no LED? Check the circuit that sets the PSU free.”
220-1101 Motherboard Practice Question
This 220-1201 practice question tests your understanding of motherboard. The scenario asks you to isolate a root cause — eliminate options that address a different problem before choosing. After answering, compare your reasoning against the explanation and wrong-answer breakdown below. Once you have made your selection, read the full explanation to reinforce the concept and understand why each distractor is designed to mislead on exam day.
A customer reports that their computer will not power on. The power supply fan does not spin, and the motherboard's power LED is off. You have verified the power cord and outlet are working. Which motherboard component is most likely causing this issue?
Clue words in this question
Noticing these words before you look at the options changes how you read each choice.
Clue: "most likely"
Why it matters: Probability qualifier — the question wants the most probable cause or outcome, not a guaranteed one. Eliminate low-probability options.
Why wrong: A dead CMOS battery can cause BIOS settings to reset but does not prevent the system from powering on; the PSU would still provide standby power.
B
Failed motherboard power-on circuit
A failed power-on circuit on the motherboard can prevent the PSU from receiving the signal to start, causing no power to the system.
C
Loose front panel power switch connector
Why wrong: A loose power switch connector would prevent the system from turning on when the button is pressed, but the PSU fan might still spin briefly if the motherboard is receiving power.
D
Incorrect BIOS settings
Why wrong: Incorrect BIOS settings can cause boot issues but do not prevent the motherboard from receiving power or the PSU from spinning its fan.
Answer the question above first, then reveal the full breakdown to understand why each option is right or wrong.
Correct answer & explanation
✓
Failed motherboard power-on circuit
The motherboard's power LED not lighting up and the PSU fan not spinning indicate a lack of standby power, which is typically supplied through the CMOS battery or the PSU itself. However, a failed CMOS battery can prevent the system from retaining BIOS settings, but it does not usually stop the PSU from providing standby power. The most common cause in this scenario is a failed power supply, but since the question focuses on the motherboard, a shorted motherboard or a failed power-on circuit is the likely culprit. The correct answer is a failed motherboard power-on circuit, as it can prevent the PSU from turning on even if the PSU is functional.
Key principle: Answer the scenario, not the keyword: identify the specific constraint before choosing the most familiar-sounding option.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
✗
Faulty CMOS battery
Why it's wrong here
A dead CMOS battery can cause BIOS settings to reset but does not prevent the system from powering on; the PSU would still provide standby power.
✓
Failed motherboard power-on circuit
Why this is correct
A failed power-on circuit on the motherboard can prevent the PSU from receiving the signal to start, causing no power to the system.
Clue confirmation
The clue word "most likely" in the question point toward this answer.
Related concept
Read the scenario before looking for a memorised answer.
✗
Loose front panel power switch connector
Why it's wrong here
A loose power switch connector would prevent the system from turning on when the button is pressed, but the PSU fan might still spin briefly if the motherboard is receiving power.
✗
Incorrect BIOS settings
Why it's wrong here
Incorrect BIOS settings can cause boot issues but do not prevent the motherboard from receiving power or the PSU from spinning its fan.
Common exam traps
Common exam trap: answer the scenario, not the keyword
Many certification questions include familiar terms but test a specific constraint. Read the exact wording before choosing an answer that is generally true but wrong for this case.
Detailed technical explanation
How to think about this question
This question should be treated as a scenario, not a definition check. Identify the problem, the constraint and the best action. Then compare each option against those facts.
KKey Concepts to Remember
Read the scenario before looking for a memorised answer.
Find the constraint that changes the correct option.
Eliminate answers that are true in general but not in this case.
Use explanations to understand the rule behind the answer.
TExam Day Tips
→Underline the problem statement mentally.
→Watch for words such as best, first, most likely and least administrative effort.
→Review why wrong options are wrong, not only why the correct option is correct.
Key takeaway
Answer the scenario, not the keyword: identify the specific constraint before choosing the most familiar-sounding option.
Real-world example
How this comes up in practice
A practitioner preparing for the 220-1201 exam encounters this exact type of scenario on the job. The correct answer here is not the most general option — it is the best answer for the specific constraint described. Answer the scenario, not the keyword: identify the specific constraint before choosing the most familiar-sounding option. Real exam questions reward reading the full scenario before eliminating options, because the constraint defines which answer fits.
Related glossary terms
Concepts from this question explained
These glossary pages explain the core terms tested in this 220-1201 question in full detail.
Identify which 220-1201 exam domain this question belongs to, then review the specific concept being tested. Practise related questions in that domain and focus on understanding why each wrong answer is tempting — not just why the correct answer is right.
Motherboard — This question tests Motherboard — Read the scenario before looking for a memorised answer..
What is the correct answer to this question?
The correct answer is: Failed motherboard power-on circuit — The motherboard's power LED not lighting up and the PSU fan not spinning indicate a lack of standby power, which is typically supplied through the CMOS battery or the PSU itself. However, a failed CMOS battery can prevent the system from retaining BIOS settings, but it does not usually stop the PSU from providing standby power. The most common cause in this scenario is a failed power supply, but since the question focuses on the motherboard, a shorted motherboard or a failed power-on circuit is the likely culprit. The correct answer is a failed motherboard power-on circuit, as it can prevent the PSU from turning on even if the PSU is functional.
What should I do if I get this 220-1201 question wrong?
Identify which 220-1201 exam domain this question belongs to, then review the specific concept being tested. Practise related questions in that domain and focus on understanding why each wrong answer is tempting — not just why the correct answer is right.
Are there clue words in this question I should notice?
Yes — watch for: "most likely". Probability qualifier — the question wants the most probable cause or outcome, not a guaranteed one. Eliminate low-probability options.
What is the key concept behind this question?
Read the scenario before looking for a memorised answer.
About these practice questions
Courseiva creates original exam-style practice questions with explanations and wrong-answer analysis. It does not publish real exam questions, exam dumps, or protected exam content. Learn why practice questions differ from exam dumps →
These questions test the same concept from different angles. Work through them to make sure you can recognise it however the exam phrases it.
Variation 1. A customer reports that their desktop PC will not power on at all. The power supply fan does not spin, and no LEDs are lit. You have verified the power cord is good and the outlet has power. Which motherboard component should you check first?
easy
A.The CMOS battery
B.The front panel power switch header
✓ C.The 24-pin ATX power connector
D.The CPU fan header
Why C: The ATX power connector (main power connector) supplies power from the PSU to the motherboard. If it is loose or disconnected, the motherboard will not receive power, causing a no-power condition. Always check this first before assuming PSU failure.
Variation 2. A customer reports that their desktop PC will not power on at all. The power supply fan does not spin, and no LEDs light up. You have verified the wall outlet is working. Which motherboard component is most likely preventing the system from starting?
easy
A.CMOS battery
✓ B.Front panel header
C.Chipset heatsink
D.CPU socket
Why B: The CMOS battery is not involved in the power-on process; it only maintains BIOS settings. The chipset and CPU are not directly responsible for the initial power-up sequence. The power-on process begins with the power button connecting to the front panel header, and if that connection is faulty, the motherboard never receives the signal to start the PSU.
Last reviewed: Jun 18, 2026
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