A technician is experiencing overheating on a rack mounted server. After powering off and removing the cover of the server, a large amount of dust is noticed on one of the fans. After cleaning out…

A failed power supply would typically cause the server to lose power or fail to POST rather than continue running with an overheating symptom specifically tied to airflow.

Excessive power draw would be a contributing factor to heat generation but does not explain why the overheating persists specifically after dust removal - it would have been a problem before the cleaning as well without pointing to the fan as a variable.

Hard drives generate relatively little heat compared to CPUs and do not produce enough thermal output to cause system-wide overheating on a rack server.

After eliminating dust as the cause, the next most logical explanation for persistent overheating is that one or more fans are mechanically defective and not spinning at rated RPM or at all. A server relies on multiple fans working in concert to move air through the chassis, and a single defective fan can create a dead zone of airflow that no amount of dust cleaning will resolve.