220-1102 Question 728
Single answerCompressed air/vacuumsA technician is cleaning dust from the inside of a desktop PC that has been shutting down due to overheating. The technician has a can of compressed air and a small electronics-safe vacuum available. Which action is the BEST way to clean the system without damaging components?
- A
Use short bursts of compressed air while preventing the fans from spinning freely, and keep the vacuum nozzle away from direct contact with components
- B
Use the vacuum directly on the motherboard and memory modules to pull dust off the components as quickly as possible
- C
Turn the can of compressed air upside down to spray liquid propellant into the heatsink fins for deeper cleaning
- D
Hold each fan blade and spin the fan manually at high speed while blowing compressed air through it
Show answer and explanation
Correct answer: A
Explanation
The best answer is to use compressed air properly: apply short bursts, keep the can upright, and prevent fans from spinning while dust is blown out. If a small electronics-safe vacuum is used, it should mainly collect dust from the surrounding area rather than be pressed directly onto sensitive internal parts. These practices align with standard PC maintenance guidance used in hardware support and reflected in CompTIA A+ objectives related to safe cleaning methods and proper use of compressed air and vacuums. Key best practices include powering down and unplugging the system first, using compressed air in a controlled manner, avoiding liquid discharge from the can, and minimizing the chance of electrostatic discharge or mechanical damage.
- A. Correct.
Correct. Best practice when cleaning internal PC components is to use short bursts of compressed air to dislodge dust while preventing fans from spinning. Allowing fans to spin freely can damage the fan bearings or generate back current. An electronics-safe vacuum may be used to collect loosened dust, but it should not be pressed directly against sensitive components due to the risk of physical damage or static-related issues.
- B. Incorrect.
Incorrect. Even if a vacuum is labeled for electronics use, placing the nozzle directly on the motherboard or RAM is not the best practice. Direct contact can physically damage small components or connectors. A common misconception is that suction alone is harmless, but internal PC parts should be cleaned carefully with airflow and limited, non-contact vacuum assistance.
- C. Incorrect.
Incorrect. Turning a compressed air can upside down can release liquid propellant rather than just gas. That can cause moisture buildup or thermal shock on components and may leave residue depending on the product. The misconception here is that more forceful spray means better cleaning, but improper orientation of the can creates unnecessary risk.
- D. Incorrect.
Incorrect. Spinning a fan manually at high speed is unsafe. Fans should be immobilized during cleaning, not forced to rotate faster. Over-spinning can damage fan bearings and, in some cases, generate voltage back into the system through the fan header. This is a common error when technicians try to clean fan blades quickly.