A 2-socket blade server in an enclosure powers itself off 10-15 minutes after the CPUs are driven to 90 % utilization. The management controller logs repeated "CPU_THERMAL_ASSERT" events, and real-time telemetry shows the processors exceeding their thermal throttle point. All four hot-swap fan modules report normal RPM, the fan tray and heat sinks have been re-seated, and fresh thermal compound was applied, yet the issue persists. Which of the following is the MOST likely root cause of the overheating?
The single-phase PDU is delivering 200 V instead of 208 V, reducing fan motor efficiency.
Dust clogging the intake and exhaust vents is restricting airflow through the chassis.
Out-of-date baseboard management controller firmware cannot interpret current CPU thermal sensors.
Faulty DIMM temperature sensors are triggering erroneous critical-temperature alerts for the CPUs.
Even when fans appear healthy and spin at their expected speed, cooling depends on a clear intake and exhaust path. Dust or debris that clogs front bezels, air filters, or heat-sink fins restricts airflow, so the same volume of air can no longer carry heat away from the CPUs. Server vendor documentation lists airflow blockage from dust as a primary cause of over-temperature shutdowns even when fan modules are reported "OK". Undervoltage from the PDU would normally trigger power or fan fault alerts long before thermal events. Out-of-date BMC firmware can cause reporting anomalies, but the processors would not consistently exceed their thermal limits within minutes if airflow were adequate because a physical shutdown indicates a real thermal event, not just a reporting error. Faulty DIMM temperature sensors would raise memory-not CPU-thermal faults and would not force the server to shut down only under high CPU load. Therefore, dust-induced airflow restriction is the most probable remaining cause.
Ask Bash
Bash is our AI bot, trained to help you pass your exam. AI Generated Content may display inaccurate information, always double-check anything important.
What is the role of intake and exhaust vents in server cooling?
Open an interactive chat with Bash
Why doesn’t undervoltage from the PDU cause overheating directly?
Open an interactive chat with Bash
How does dust clogging impact cooling even if fans are functioning properly?