Troubleshooting The Cooling Subsystem - Cisco ASR 9901 Hardware Installation Manual

Troubleshooting the Installation
• show diag slot
• show context location slot
Along with these show commands, you should also gather the following information:
• Console Logs and Syslog Information—This information is crucial if multiple symptoms are occurring.
• Additional Data—The show tech-support command is a compilation of many different commands,
For examples of how to use these commands and the resulting output, see the Cisco ASR 9000 Series
Troubleshooting Guide.
Note It is important to collect the show tech-support command data before doing a reload or power cycle. Failure
to do so can cause all information about the problem to be lost. Output from these commands varies slightly
depending on which line card you are using, but the basic information is the same.

Troubleshooting the Cooling Subsystem

You may need to troubleshoot the cooling subsystem if an over-temperature condition occurs. The cooling
subsystem of the router consists of a fan tray in the chassis and a fan in each of the power supplies. The fan
tray and the power supply fans circulate air to maintain acceptable operating temperatures within the router.
Fan Tray Operation
The fan tray maintains acceptable operating temperatures for the internal components by drawing cooling air
into the system chassis. The fan tray receives power from the chassis backplane.
The Cisco ASR 9901 uses 3 individual fan trays. The Cisco ASR 9001 uses a single fan tray that contains 14
fans. Each fan tray has a controller card and one front panel STATUS LED indicator:
• Green—Fan tray is functioning properly.
• Red—There is a fault detected in the fan tray.
Note The Cisco ASR 9901 also has a front panel fan fault LED. See
If the air temperature inside the chassis rises, blower speed increases to provide additional cooling air to the
internal components. If the internal air temperature continues to rise beyond the specified threshold, the system
environmental monitor shuts down all internal power to prevent equipment damage because of excessive heat.
If the system detects that one or more of the fans in the fan tray has failed, it displays a warning message on
the system console. In addition, the remaining fans go to full speed to compensate for the loss of the failed
fan.
If the router is configured to send logs to a Syslog server, you may see some information on what has
occurred. For console logs, it is best to be directly connected to the router on the console port with logging
enabled.
including show version, show running-config, show tech ethernet, show tech pfi, and show stacks. This
information is required when working on issues with the Cisco Technical Assistance Center (Cisco TAC).
Cisco ASR 9901, ASR 9001, and ASR 9001-S Routers Hardware Installation Guide
Troubleshooting the Cooling Subsystem
RP Front Panel Indicators.
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