This article captures some of the log messages and chassis alarms that are seen for Fan Tray Failures.

Chassis Alarms / Signatures Examples

root@hostname> show chassis alarms no-forwarding

• DAEMON-X: Major alarm set (***)

• ***The alarm can be Fan Tray Failure OR Bottom Fan Tray Failure OR Left Fan Tray Failure OR Top/Bottom Fan Tray Failure.

Log Messages / Signatures Examples

root@hostname> show log message / show log chassisd

The logs can be similar to any one of the following:

• send: red alarm set, device Left Fan Tray X, reason Left Fan Tray Failure

• craftd[]: %DAEMON-X: Major alarm set, Left Fan Tray Failure

• alarmd[]: Alarm set: Fan id=x, color=RED, class=CHASSIS, reason=Bottom Fan Tray Failure

• CHASSISD_FAN_FAILURE: Left Fan Tray in slot 0 failed

Engage a technician onsite, and check for any damages/issue with the fan tray. Check whether the air inflow and surrounding temperature are normal.

For units mounted in a cabinet, it is important to secure sufficient clearance around the rack, without any objects (e.g. cables) blocking both the inlet and exhaust areas of the router, and to ensure regular inspection of the air filter and its cleanliness.

Inspect the air filters for dirt/dust. A dirty air filter restricts airflow in the unit, producing a negative effect on the ventilation of the chassis.

Re-seat the fan tray and verify the status.

If a spare fan is available, test it on the faulty slot to confirm the issue. And if replacing the malfunctioning fan with a spare resolves the issue, proceed to request an RMA for the faulty fan.

Note: We recommend that you perform this activity during a maintenance window. Also, to prevent overheating, install the replacement fan tray immediately after removing the existing fan tray.

Troubleshooting commands

• user> show chassis environment 

• user> show chassis fan

• user> show chassis alarms

• user> show system alarms

• user> show log messages | match fan

• user> show log chassisd | match fan

• user> test chassis fan (available only in some platforms) 

Related KBs

• KB74302 - [MX960] - Major alarm - Bottom Fan Tray Failure [juniper.net]

• KB75658 - [MX480] Major Alarm: Left Fan Tray Failure [juniper.net]

• KB72346 - [MX960] Syslog message: Major alarm set, Top/Bottom Fan Tray Failure with Under Voltage [juniper.net]

• KB71519 - [MX]Major Alarm: Fan Tray [X] Pair [X] Inner Fan stopped due to rotor failure/Fan Tray [X] Pair [X] Outer Fan stopped due to rotor failure [juniper.net]

2024-04-25: Minor, non-technical changes

2024-02-28: Article created