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220-1102 Practice Question: A technician is cleaning the inside of a desktop…
A technician is cleaning the inside of a desktop computer that has accumulated a large amount of dust. What is the safest method to remove the dust?
⚠ Common exam trap
Candidates often assume a vacuum cleaner is safe because it 'sucks' dust away, but CompTIA tests the understanding that vacuum cleaners generate dangerous static charges and lack the precision needed for delicate electronics.
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
✓
Use compressed air to blow the dust out of the case.
Compressed air is the safest method because it dislodges dust without physical contact, avoiding electrostatic discharge (ESD) or mechanical damage to sensitive components. Unlike other methods, it does not introduce moisture or static buildup, and it can reach tight spaces between heatsinks and circuit boards.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
- ✗
Use a standard household vacuum cleaner with a brush attachment.
Why it's wrong here
Household vacuum cleaners are unsuitable for cleaning computer interiors primarily due to their propensity to generate significant electrostatic discharge (ESD). The friction of air and dust particles moving rapidly through the plastic nozzle and hose can create static electricity, which can fatally damage sensitive integrated circuits without immediate visible signs. Furthermore, their powerful suction can dislodge delicate surface-mounted components or cause physical stress, and they lack the fine filtration required for computer dust, potentially recirculating fine particles.
- ✓
Use compressed air to blow the dust out of the case.
Why this is correct
Compressed air is the industry-standard and recommended method for removing dust from computer interiors because it effectively dislodges particulate matter from intricate components without physical contact. When used correctly, holding the can upright and in short, controlled bursts, it prevents propellant discharge and minimizes static buildup. It is crucial to hold fan blades stationary while blowing to prevent over-spinning, which can damage bearings or generate back-electromotive force (back-EMF) that could harm the motherboard's fan controller circuitry.
- ✗
Use a damp cloth to wipe down the components.
Why it's wrong here
Introducing any moisture, even from a damp cloth, into a computer's interior poses severe risks, including immediate short circuits on powered or recently powered components. Water is conductive and can bridge electrical pathways, leading to irreversible damage to integrated circuits, traces, and power regulation modules. Over time, residual moisture can also accelerate oxidation and corrosion on delicate metal contacts, solder joints, and component pins, compromising long-term reliability and potentially causing intermittent failures.
- ✗
Use a soft brush to sweep the dust out.
Why it's wrong here
While seemingly gentle, a soft brush can generate electrostatic discharge (ESD) through friction as its bristles contact various components and dust particles, potentially damaging sensitive electronics. Moreover, brushes are often ineffective at thoroughly removing dust from tightly packed areas like heatsink fins, fan blades, or inside power supply units, leaving significant accumulation. There is also a risk of accidentally dislodging small, surface-mounted components or bending delicate pins during the sweeping action, leading to physical damage.
Go deeper
Related to this question
Learn chapter
Windows Installation Methods
Key term
Electrostatic discharge
Electrostatic discharge (ESD) is the sudden flow of electricity between two objects with different electrical charges, often caused by built-up static electricity, which can damage sensitive electronic components.
Key term
ESD
Electrostatic Discharge is the sudden flow of electricity between two electrically charged objects caused by contact or an electrical short, which can damage sensitive electronic components.
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JA
Written by Johnson Ajibi, MSc IT Security
Senior Network & Security Engineer · founder of Courseiva
This 220-1202 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 220-1202 exam.