Troubleshooting The T640 Cooling System - Juniper T640 Hardware Manual

T640 Core Router Hardware Guide
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Troubleshooting the T640 Cooling System

Problem
Solution
168
Table 31: SONET/SDH Interface Alarm Messages (continued)
LCD Message
interface-name so-x/x/x REI
interface-name so-x/x/x SEF
interface-name so-x/x/x UNEQ
T640 Chassis Description on page 13
T640 Craft Interface Alarm LEDs and ACO/LT Button on page 42
Overview of Connecting the T640 Router to Management and Alarm Devices on page 117
Replacing a T640 Craft Interface on page 196
The following alarms and LEDs indicate a problem when:
A fan fails (red alarm).
One of the fan trays is removed (yellow alarm).
A front or rear fan trays is functioning 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.
The router temperature exceeds the "temperature warm" threshold (yellow alarm).
The temperature of the router exceeds the maximum ("temperature hot") threshold
(red alarm and automatic shutdown of the power supplies).
NOTE: If the router temperature exceeds the acceptable maximum, the T-CB
turns off the power supplies.
During normal operation, the fans in both front and rear fan trays function at less than
full speed.
To troubleshoot the fans, follow these guidelines:
If the red alarm LED on the craft interface lights, find the source of the problem by
looking at the display on the craft interface. The number of alarm conditions, as well
as the source of each alarm, appears on the screen.
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
CLI Message
interface-name so-x/x/x - SONET remote error indicator
interface-name so-x/x/x - SONET severely errored frame
interface-name so-x/x/x - SONET unequipped
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