Troubleshooting the Cooling System on the SRX3600 Services Gateway

The services gateway cooling system consists of a fan tray and an air filter, both of which are located vertically in the rear of the chassis. The fan tray contains 10 fans. The fan tray provides cooling to the components installed in the services gateway.

An air filter installed in the rear of the chassis helps keep dust and other particles from entering the cooling system. To function properly, the entire cooling system requires an unobstructed airflow and proper clearance around the site, as described in Site Preparation Checklist for the SRX3600 Services Gateway.

During normal operation, the fans in the fan tray function at less than full speed. The Routing Engine constantly monitors the temperatures detected by sensors and services gateway components, adjusting the speed of the fans as necessary. If the services gateway temperature exceeds the acceptable maximum, the Routing Engine turns off the power supplies. The following conditions automatically cause the fans to run at full speed and also trigger the indicated alarm:

• A fan fails (red alarm).
• The fan tray is removed (yellow alarm and red alarm).
• The services gateway temperature exceeds the “temperature warm” threshold (yellow alarm).
• The temperature of the services gateway exceeds the maximum (“temperature hot”) threshold (red alarm and automatic shutdown of the power supplies).

To troubleshoot the fans, follow these guidelines:

• If the FAN LED on the SFB lights red, use the CLI to get information about the source of an alarm condition:
  user@host> show chassis alarms

  If the CLI output lists only one fan failure, and the other fans are functioning normally, the fan is most likely faulty and you need to replace the fan tray, as described in Replacing the Fan Tray on the SRX3600 Services Gateway.

• Place your hand near the exhaust vents at the side of the chassis to determine whether the fans are pushing air out of the chassis.
• If all power supplies have failed, the system temperature might have exceeded the threshold, causing the system to shut down.