220-1201 Practice Question: A customer brings in a PC that was working fine…

Answer analysis

Option-by-option breakdown

For each option: why learners choose it and why it is or isn't the right answer here.

• ✗

  The power supply is failing under load.

  Why it's wrong here

  A power supply failing under load typically manifests as intermittent shutdowns, system instability, or reboots, especially during demanding tasks. However, an immediate shutdown within 2 seconds without any fan spin (implying the system didn't even attempt to power on fully or detect a fan) is less characteristic of a PSU failing under load and more indicative of a protective shutdown triggered by a critical sensor, such as a missing CPU fan signal. A completely dead PSU would yield no power at all.

• ✓

  The CPU fan header is disconnected from the motherboard.

  Why this is correct

  Modern motherboards incorporate critical safety features, including CPU fan monitoring. If the motherboard's CPU fan header is disconnected or the fan itself is faulty, the system's BIOS/UEFI firmware will detect the absence of a CPU fan signal during the Power-On Self-Test (POST) or initial boot sequence. To prevent potential thermal damage to the CPU, the system will immediately initiate a protective shutdown, often within seconds of power-on, regardless of the actual CPU temperature. This rapid shutdown is a preventative measure.

• ✗

  The CPU is not seated properly.

  Why it's wrong here

  If the CPU is not seated correctly in its socket, or if pins are bent, the system typically fails to POST entirely. This would result in a blank screen, no video output, and often specific beep codes from the motherboard indicating a CPU or memory initialization error. An immediate shutdown after 2 seconds, especially with initial power but no fan spin, is not the primary symptom of a poorly seated CPU, which usually prevents the system from even beginning the boot process effectively.

• ✗

  The case power button is stuck in the pressed position.

  Why it's wrong here

  A case power button stuck in the pressed position would typically cause the system to power on, then immediately power off, or continuously cycle power on and off, as if the user were repeatedly pressing and holding the power button. It would not result in a single, immediate shutdown after 2 seconds without further attempts to power on or cycle. This scenario usually points to a different protective mechanism or component failure.

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