We observed unusual sound from the FAN module. All fans are working fine but sound is there.

Actions Taken:

FAN tray cleaning performed during PM.

Tested with a spare FAN; sound normalized, then reverted to original FAN.

Inspection suggests FAN leaf intermittently touching outer body.

Environment Check:

Temperature, airflow, and rack cooling normal.

No alarms on node; fans spinning at normal speed; voltages normal.

show chassis environment | match Fan

Fans Fan 1 OK Spinning at normal speed

Fan 2 OK Spinning at normal speed

Fan 3 OK Spinning at normal speed

Fan 4 OK Spinning at normal speed

Fan 5 OK Spinning at normal speed

Nov 13 07:39:31.533 2025 JM104-re0 chassisd[2134]: %DAEMON-5-CHASSISD_BLOWERS_SPEED_MEDIUM: Fans and impellers being set to intermediate speed

Nov 13 07:45:31.654 2025 JM104-re0 chassisd[2134]: %DAEMON-5-CHASSISD_BLOWERS_SPEED: Fans and impellers are now running at normal speed

Nov 13 09:01:22.540 2025 JM104-re0 chassisd[2134]: %DAEMON-5-CHASSISD_BLOWERS_SPEED_MEDIUM: Fans and impellers being set to intermediate speed

Nov 13 09:20:37.759 2025 JM104-re0 chassisd[2134]: %DAEMON-5-CHASSISD_BLOWERS_SPEED_MEDIUM: Fans and impellers being set to intermediate speed

Nov 13 09:26:12.902 2025 JM104-re0 chassisd[2134]: %DAEMON-5-CHASSISD_BLOWERS_SPEED: Fans and impellers are now running at normal speed

From logs, its clear that there are no software level issues or HW alarms.

But from the testing with spare fan tray, its clear the issue is indeed with Fan leaf touching chassis.

Hence the fan tray was replaced with via RMA.