| Step | Action | Expected Result | What It Means | |------|--------|----------------|---------------| | | Check the front panel LEDs – look for over‑temperature or fan‑failure warnings. | Green/blue steady = normal; amber/red flashing = fault. | A warning LED often pinpoints the problem area. | | B | Listen for fan RPM – fans should spin up smoothly, producing a steady, low‑noise whirr. | Normal fan sound, no grinding. | Abnormally quiet fans → obstruction or failure; noisy fans → bearing wear. | | C | Measure inlet/outlet temperature with an infrared thermometer or built‑in sensor readout (via UI/CLI). | Inlet ≤ 25 °C, outlet ≤ 35 °C (ΔT ≈ 10 °C). | ΔT too low → insufficient airflow; ΔT too high → internal heat build‑up. | | D | Run a hardware health check via the device’s management console (e.g., IPMI, web UI, or CLI). | No “thermal throttling” or “fan error” messages. | Confirms software‑level alerts. | | E | Inspect physical environment – check rack spacing, surrounding equipment, and room temperature. | Minimum 2U clearance on all sides, ambient ≤ 30 °C. | Over‑crowded racks trap heat. |

Using the wrong type of light bulb can radiate excessive heat directly into the control assembly.