In desktop PC assembly, what is the most likely technical consequence of leaving metal slot covers missing on the back of the chassis?

Introduction / Context:
Rear expansion slots should be closed with metal covers when not occupied. These covers contribute to electromagnetic compatibility (EMC) and proper airflow. Understanding the primary risk helps technicians prioritize re-installing covers after service.

Given Data / Assumptions:

• PC chassis uses standard ATX-style rear slots.
• System environment includes nearby devices susceptible to interference.
• No additional shielding or RF gasketing is present.

Concept / Approach:
Open slots create apertures that allow electromagnetic emissions to leak and external noise to enter, compromising EMC. While airflow can also be affected (which may contribute to heat issues), the canonical and exam-focused answer is increased EMI risk due to inadequate shielding of the enclosure.

Step-by-Step Solution:

Verification / Alternative check:
EMC testing consistently shows enclosure apertures increase emissions. Manufacturers include slot covers to pass regulatory limits (e.g., CE/FCC).

Why Other Options Are Wrong:

• Power surges: Caused by supply anomalies, not slot openings.
• Incomplete path for ESD: Grounding paths are not defined by slot covers.
• Overheating: Airflow can be affected, but EMI is the primary standardized concern.
• None of the above: Incorrect because EMI risk is real and documented.

Common Pitfalls:
Assuming missing covers “vent heat better,” ignoring that chaotic airflow can worsen cooling and that EMC compliance is compromised.

Final Answer:
EMI (electromagnetic interference)