220-1101 Hardware Practice Question
A technician assembles a new desktop computer using a third-party CPU cooler. After powering on, the CPU temperature rapidly rises to 95°C within a few seconds, and the CPU fan spins at maximum speed. The technician verifies that the thermal paste is applied correctly and that the CPU fan is connected to the CPU_FAN header. Which of the following is the MOST likely cause of the high temperature?
⚠ Common exam trap
Many exam-takers assume a spinning fan and correct paste application guarantee proper cooling, overlooking that the heatsink must be physically seated with even pressure to transfer heat effectively.
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
✓
The heatsink is not properly seated or the mounting pressure is uneven
The rapid temperature spike to 95°C within seconds, despite correct thermal paste application and fan connection to the CPU_FAN header, indicates that the heatsink is not making proper thermal contact with the CPU. Uneven mounting pressure or an improperly seated heatsink creates air gaps that drastically reduce heat transfer efficiency, causing the CPU to overheat immediately under even idle power draw.
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 CPU is not compatible with the motherboard
Why it's wrong here
If the CPU were incompatible with the motherboard, the system would typically fail to POST or power on at all, as the BIOS would reject the chip or the socket would physically not match. In rare cases where the CPU fits but is unsupported, the board may not provide the correct Vcore or microcode, preventing the processor from executing code entirely. A running system that overheats after only seconds indicates the CPU is actively processing, which would be impossible with an incompatible part, so this cannot be the cause.
- ✗
The CPU fan connector is plugged into a chassis fan header
Why it's wrong here
The technician confirmed the fan is plugged into the CPU_FAN header. Even if it were on a chassis header, the fan would still spin, but the system might report a CPU fan error; it would not cause the CPU to overheat rapidly.
- ✓
The heatsink is not properly seated or the mounting pressure is uneven
Why this is correct
An improperly seated heatsink or uneven mounting pressure is the classic cause of rapid CPU overheating on a newly assembled system. If the heatsink base does not make full contact with the CPU's heat spreader, air gaps act as thermal insulators, preventing heat from being transferred away from the die. Uneven pressure can also cause the heatsink to tilt, reducing contact area on one corner and causing a hot spot that trips thermal protection almost immediately after boot. This is particularly common with third-party coolers that require a specific installation order or torque.
- ✗
The power supply unit is underpowered for the CPU
Why it's wrong here
An underpowered power supply would not selectively overheat the CPU while the rest of the system runs normally. Instead, it would cause system-wide instability, random shutdowns under load, or a complete failure to boot, because the 12V rail cannot sustain the peak current demand. Even if the PSU were marginal, the CPU would likely throttle or the system would crash before it could generate dangerous temperatures, making rapid thermal buildup an unlikely symptom.
Go deeper
Related to this question
About these practice questions
Courseiva writes every 220-1101 question from scratch — 896 in total, each with an explanation and a wrong-answer breakdown. None are copied from real exams or dumps. Learn why practice questions differ from exam dumps →
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.