PC Won't Power On: Connect Front Panel Power Switch Header Correctly
A technician has just completed building a new desktop computer. After connecting all components and closing the case, the technician presses the power button on the front of the case, but nothing happens. No fans spin, no lights come on. The technician has verified that the power supply unit (PSU) works by testing it in another system. Which of the following should the technician check FIRST?
Quick Answer
The answer is to connect the front panel power switch header to the correct motherboard pins. This is the first thing to check when a new build PC won’t power on at all because the power button on the case is simply a momentary switch that closes a circuit on the motherboard’s front panel header; if that tiny two-pin connector is placed on the wrong pins or isn’t fully seated, pressing the button sends no signal to the PSU to turn on. Since you’ve already verified the power supply works in another system, this wiring error is the most logical and common culprit before suspecting a faulty motherboard or CPU. On the CompTIA A+ Core 1 220-1101 exam, this scenario tests your understanding of the front panel header layout and the importance of checking simple connections first—a common trap is to immediately blame the PSU or motherboard. A helpful memory tip: think of the front panel header as the “handshake” between the case and the board; no handshake, no power.
⚠ Common exam trap
CompTIA often tests the candidate's ability to prioritize the simplest, most common assembly error (front panel wiring) over more complex hardware faults like a dead CMOS battery or CPU seating, which would produce different symptoms (e.g., power-on but no POST) rather than a completely dead system.
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
✓
Connect the front panel power switch header to the correct motherboard pins.
The most likely cause of a completely dead system (no fans, no lights) after building a new PC is that the front panel power switch is not properly connected to the motherboard. The power button on the case is a momentary switch that completes a circuit on the motherboard's front panel header; if the connector is on the wrong pins or not seated, pressing the button does nothing. Since the PSU has been verified working in another system, the next logical step is to check this simple, common wiring error before moving to more complex hardware troubleshooting.
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 CMOS battery on the motherboard.
Why it's wrong here
A dead CMOS battery causes lost BIOS settings and clock drift, not a complete absence of power-on response. It is tempting because it is a common POST failure cause, but it would be correct when the system powers on yet reports configuration or time errors, not when nothing responds.
When this WOULD be correct
A technician replaces the CMOS battery when a computer fails to boot, displays incorrect time/date, or loses BIOS settings after power-off. For example, if a system powers on but shows 'CMOS checksum error' or resets BIOS settings each boot, replacing the battery is the correct first step.
- ✓
Connect the front panel power switch header to the correct motherboard pins.
Why this is correct
A completely dead system with a verified PSU points to the front panel power switch not being connected to the motherboard's power header, so the button cannot signal startup. Checking that header first is the quickest diagnostic step.
- ✗
Reseat the CPU in the socket.
Why it's wrong here
A misseated CPU typically still allows fans and standby power to respond, and would usually produce a POST failure rather than total silence. Reseating is tempting after a fresh build, but it would be correct when the system powers on yet fails to POST, not when no power reaches the board.
When this WOULD be correct
If the computer powers on (fans spin, lights come on) but fails to POST or beeps, and the CPU was recently replaced or the system was moved, reseating the CPU would be a valid step to check for poor contact.
- ✗
Test the power supply using a multimeter.
Why it's wrong here
The PSU was already verified in another system, so retesting it with a multimeter repeats completed work and delays diagnosis. Multimeter testing is tempting as a standard power check, but it would be correct when PSU output is unverified, not when the fault lies in front-panel or board connections.
When this WOULD be correct
When the question states that the PSU has not been tested in another system and the technician needs to confirm if the PSU is outputting correct voltages before proceeding with other troubleshooting steps.
Option-by-option analysis
Why each answer is right or wrong
Understanding why wrong answers are wrong — and when they would be correct — is what separates a 750 score from a 900. The 220-1101 exam frequently reuses these exact scenarios with slightly different constraints.
✓Connect the front panel power switch header to the correct motherboard pins.Correct answer▾
Why this is correct
A completely dead system with a verified PSU points to the front panel power switch not being connected to the motherboard's power header, so the button cannot signal startup. Checking that header first is the quickest diagnostic step.
✗Replace the CMOS battery on the motherboard.Wrong answer — click to see why▾
Why this is wrong here
The CMOS battery is responsible for maintaining BIOS settings and the real-time clock, not for powering on the system. Since the PSU is verified working and no power reaches any component, the issue is likely a missing connection between the power button and motherboard, not a depleted battery.
★ When this WOULD be the correct answer
A technician replaces the CMOS battery when a computer fails to boot, displays incorrect time/date, or loses BIOS settings after power-off. For example, if a system powers on but shows 'CMOS checksum error' or resets BIOS settings each boot, replacing the battery is the correct first step.
Why candidates choose this
Candidates may mistakenly think the CMOS battery provides startup power or that a dead battery prevents any power-on activity, confusing its role in maintaining settings with the power-on circuit.
✗Reseat the CPU in the socket.Wrong answer — click to see why▾
Why this is wrong here
The CPU is already installed and the system was just built; if the CPU were improperly seated, the technician would likely have noticed during assembly, and the symptom of no power at all (no fans, no lights) is not typical of a CPU seating issue—that usually causes a POST failure with fans spinning.
★ When this WOULD be the correct answer
If the computer powers on (fans spin, lights come on) but fails to POST or beeps, and the CPU was recently replaced or the system was moved, reseating the CPU would be a valid step to check for poor contact.
Why candidates choose this
Candidates may think any hardware issue after building a PC could be due to improper CPU installation, and they might confuse 'no power' with 'no POST' symptoms.
✗Test the power supply using a multimeter.Wrong answer — click to see why▾
Why this is wrong here
Testing the power supply with a multimeter is unnecessary because the technician has already verified the PSU works in another system. The issue is likely a connection problem, not a PSU failure.
★ When this WOULD be the correct answer
When the question states that the PSU has not been tested in another system and the technician needs to confirm if the PSU is outputting correct voltages before proceeding with other troubleshooting steps.
Why candidates choose this
Candidates may think a multimeter test is the definitive way to check a PSU, overlooking that the simpler test of swapping into a known working system already confirmed it works.
Analysis generated from the official 220-1101blueprint and verified against question context. The “when correct” sections are what AI assistants cite when candidates ask “what’s the difference between these options?”
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One of 896 original 220-1101 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 →
Same concept, more angles
1 more way this is tested on 220-1101
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 technician is building a new desktop PC from components. After installing the motherboard, CPU, RAM, and power supply, the technician needs to connect the front panel power switch to the motherboard. Which of the following motherboard headers should the technician connect the power switch cable to?
easy- A.PWR_LED (Power LED) header
- ✓ B.PWR_BTN (Power Button) or POWER_SW header
- C.RESET (Reset Button) header
- D.SPEAKER header
Why B: The front panel power switch cable must be connected to the motherboard header labeled PWR_BTN or POWER_SW. This header completes a momentary contact circuit that signals the power supply to turn on when the switch is pressed, initiating the system boot sequence.
JA
Written by Johnson Ajibi, MSc IT Security
Senior Network & Security Engineer · founder of Courseiva
This 220-1101 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 220-1101 exam.