220-1101 Question 299
Single answerHeat sinkA technician replaces a desktop PC's failed CPU fan and reapplies the existing heat sink. After the repair, the computer powers on but shuts down after a few minutes of use, and the BIOS reports unusually high CPU temperatures. Which action should the technician take FIRST to most likely resolve the overheating issue?
- A
Remove the heat sink, clean off the old thermal compound, apply new thermal paste, and reinstall the heat sink correctly
- B
Increase the monitor refresh rate to reduce CPU load and lower system temperature
- C
Replace the power supply because insufficient wattage commonly causes CPU overheating after fan replacement
- D
Disable CPU power-saving features in BIOS so the processor runs at a constant speed
Show answer and explanation
Correct answer: A
Explanation
This scenario tests practical troubleshooting of a CPU cooling issue involving the heat sink. In real-world service, if a heat sink is removed, the thermal interface material should generally be cleaned and replaced before reinstallation. Proper contact pressure and correct mounting are also essential. Common symptoms of a poorly seated heat sink or dried/reused thermal paste include high CPU temperatures in BIOS, thermal throttling, and automatic shutdowns. This aligns with standard PC repair best practices and CPU cooler installation guidance from major hardware manufacturers, which emphasize removing old compound with an appropriate cleaner, applying fresh thermal paste, and securing the heat sink evenly.
- A. Correct.
This is correct. When a heat sink is removed or reseated, best practice is to clean off the old thermal compound and apply a fresh, appropriate amount of new thermal paste before reinstalling the heat sink securely. Reusing old compound or improperly seating the heat sink can create poor thermal transfer between the CPU and heat sink, causing rapid overheating and thermal shutdowns.
- B. Incorrect.
This is incorrect. Monitor refresh rate does not meaningfully address CPU overheating caused by poor heat sink contact or degraded thermal compound. This option reflects a misunderstanding between display settings and processor cooling.
- C. Incorrect.
This is incorrect. A failing or undersized power supply can cause instability or shutdowns, but it does not specifically explain a BIOS report of high CPU temperature immediately after heat sink and fan service. The timing of the issue strongly points to a cooling installation problem rather than a power delivery issue.
- D. Incorrect.
This is incorrect. Disabling CPU power-saving features would typically increase heat output, not reduce it. While BIOS settings can affect thermals, this does not address the likely root cause: improper heat sink installation or bad thermal interface material.