Troubleshooting the T4000 Cooling System
Problem:
Description:
The following alarms, LEDs, and other conditions indicate a problem with the cooling system:
A red alarm indicates that the temperature of the router exceeds the maximum (“temperature hot”) threshold.
Automatic shutdown of the power supplies can be caused by the temperature of the router exceeding the maximum (“temperature hot”) threshold. The control board turns off the power supplies because the router temperature exceeds the acceptable maximum.
A red alarm indicates that a fan failed.
A yellow alarm indicates that the router temperature exceeds the “temperature warm” threshold.
A yellow alarm indicates that one of the fan trays was removed.
One or more fans in a fan tray function at full speed. The control boards constantly monitor the temperatures detected by sensors on the midplane and router components, adjusting the speed of the fans as necessary. If one fan fails, the host subsystem adjusts the speed of the remaining fans to maintain proper cooling.
Table 1: T4000 Cooling System Fan Tray Alarms
Alarm Type | LCD Message | CLI Message | Alarm Condition | Solution |
|---|---|---|---|---|
Red | Fan Failure | fan-name Failure | A fan has failed. | Replace the fan tray. |
Fans Missing | Too many fans missing or failing | A fan tray is missing or too many fan trays have failed. | Reinstall the fan tray in the chassis. | |
<fan-name> Improper | <fan-name> Improper for Platform | A fan tray is unsupported for the T4000 router. | Replace with an appropriate fan tray. For a list of supported fan trays, see T4000 Cooling System Description. | |
Incompatible rear fan tray or front fan tray detected | An incompatible fan tray is inserted into the chassis. | Replace with an appropriate fan tray. | ||
Yellow | Fan Removed | fan-name Removed | A fan tray has been removed. | Reinstall the fan tray in the chassis. |
Table 2: T4000 Temperature Alarms
Alarm Type | Craft Interface LCD Message | CLI Message | Alarm Condition | Solution |
|---|---|---|---|---|
Red | Temperature Hot | Temperature Hot | The chassis temperature exceeded the recommend hot temperature threshold. If this condition persists, the router shuts down. |
|
Sensor Failure | Temperature sensor failure | A temperature sensor failed. | Contact JTAC. | |
Yellow | Temperature Warm | Temperature Warm | The chassis temperature exceeded the recommended warm temperature threshold. |
|
Solution
To troubleshoot the cooling system:
- Check the red and yellow alarm LEDs on the craft interface.
- Find the source of the problem by looking at the craft interface display. The number of alarm conditions, as well as the source of each alarm, appears on the screen. If the craft interface display lists only one fan failure and the other fans are functioning normally, the fan is probably faulty and you need to replace the fan tray.
- Use the show chassis alarms command to get
information about the source of an alarm condition:
user@host> show chassis alarms - Use the show chassis fan command to verify
that the status of each fan is OK and that the output display
indicates that each of the fans are Spinning at normal speed.
user@host> show chassis fanItem Status RPM Measurement Top Left Front fan OK 3420 Spinning at normal speed Top Left Middle fan OK 3420 Spinning at normal speed Top Left Rear fan OK 3450 Spinning at normal speed Top Right Front fan OK 3420 Spinning at normal speed Top Right Middle fan OK 3420 Spinning at normal speed Top Right Rear fan OK 3420 Spinning at normal speed Bottom Left Front fan OK 3420 Spinning at normal speed Bottom Left Middle fan OK 3450 Spinning at normal speed Bottom Left Rear fan OK 3360 Spinning at normal speed Bottom Right Front fan OK 3420 Spinning at normal speed Bottom Right Middle fan OK 3420 Spinning at normal speed Bottom Right Rear fan OK 3420 Spinning at normal speed Rear Tray Top fan OK 5190 Spinning at normal speed Rear Tray Second fan OK 5190 Spinning at normal speed Rear Tray Third fan OK 5190 Spinning at normal speed Rear Tray Fourth fan OK 5190 Spinning at normal speed Rear Tray Fifth fan OK 5190 Spinning at normal speed Rear Tray Sixth fan OK 5190 Spinning at normal speed Rear Tray Seventh fan OK 5190 Spinning at normal speed Rear Tray Bottom fan OK 5190 Spinning at normal speedThe fans in the fan trays are listed as follows:
Upper front fan tray—Top Left and Top Right
Lower front fan tray—Bottom Left and Bottom Right
Rear fan tray—Rear
- Use the show chassis environment command to
check the status and speed of the fans.
user@host> show chassis environmentClass Item Status Measurement ... Fans Top Left Front fan OK Spinning at normal speed Top Left Middle fan OK Spinning at normal speed Top Left Rear fan OK Spinning at normal speed Top Right Front fan OK Spinning at normal speed Top Right Middle fan OK Spinning at normal speed Top Right Rear fan OK Spinning at normal speed Bottom Left Front fan OK Spinning at normal speed Bottom Left Middle fan OK Spinning at normal speed Bottom Left Rear fan OK Spinning at normal speed Bottom Right Front fan OK Spinning at normal speed Bottom Right Middle fan OK Spinning at normal speed Bottom Right Rear fan OK Spinning at normal speed Rear Tray Top fan OK Spinning at normal speed Rear Tray Second fan OK Spinning at normal speed Rear Tray Third fan OK Spinning at normal speed Rear Tray Fourth fan OK Spinning at normal speed Rear Tray Fifth fan OK Spinning at normal speed Rear Tray Sixth fan OK Spinning at normal speed Rear Tray Seventh fan OK Spinning at normal speed Rear Tray Bottom fan OK Spinning at normal speed...Top Left and Top Right refer to fans in the upper front fan tray. Bottom Left and Bottom Right refer to fans in the lower front fan tray. Rear refers to the fans in the rear fan tray.