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Troubleshooting the T1600 Cooling System

 

Problem:

Description:

The following alarms, LEDs, and other conditions indicate a problem with the cooling system:

  • A red alarm indicates that temperature of the router exceeds the maximum (“temperature hot”) threshold.

  • Automatic shutdown of the power supplies was 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.

In Table 1, the text in the column labeled ”LCD Message” appears in the display of the craft interface. The text in the column labeled “CLI Message” appears in the output from the show chassis alarms command.

Table 1: T1600 Cooling System Alarms

Component

Alarm Type

LCD Message

CLI Message

Alarm Condition

Solution

Fans

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.

T1600 Rear Fan Tray in LCC

T1600 Rear Fan Tray in LCC

For T1600 routers in a routing matrix, the rear fan tray part number 760-009870 is not supported.

Replace the rear fan tray with part number 760-024613.

Yellow

Fan Removed

fan-name Removed

A fan tray has been removed.

Reinstall the fan tray in the chassis.

Mix of FAN-TRAYS

Minor – Mix of FAN-TRAYS

A mix of standard front fan trays and quiet front fan trays are installed in the chassis.

Note: During normal operations, mixing the standard and quiet fan trays is not supported.

Check that all fan trays are either standard fan trays or quiet fan trays. Install the correct fan trays.

Note: During an upgrade, ignore this alarm.

Temperature sensors

Red

Temperature Hot

Temperature Hot

The chassis temperature exceeded the hot temperature threshold. If this condition persists, the router shuts down.

  • Verify that the room temperature is within acceptable limits.

  • Verify that there is sufficient air flow.

  • Verify that the cooling system in the chassis is operating properly.

Sensor Failure

Temperature sensor failure

A temperature sensor failed.

Contact JTAC.

Yellow

Temperature Warm

Temperature Warm

The chassis temperature exceeded the warm temperature threshold.

  • Verify that the room temperature is within acceptable limits.

  • Verify that there is sufficient air flow.

  • Verify that the cooling system in the chassis is operating properly.

Solution

To troubleshoot the cooling system:

  1. Place your hand near the exhaust vents at the rear of the chassis to determine whether the fans are pushing air out of the chassis.
  2. If the red alarm LED on the craft interface lights, look at the craft interface display to find the source of the problem. The number of alarm conditions, as well as the source of each alarm, appears on the screen.
  3. 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.
  4. Use the CLI to check the status of the fans. For example, you can issue the following command to get information about the source of an alarm condition:
    user@host> show chassis alarms

    For information about the alarms, see Table 1.