Troubleshooting The Mx480 Cooling System; Troubleshooting The Mx480 Dpcs - Juniper MX480 Hardware Manual

MX480 3D Universal Edge Router Hardware Guide

Troubleshooting the MX480 Cooling System

Problem
Solution
Related
Documentation

Troubleshooting the MX480 DPCs

Problem
Solution
144
The fans in the fan tray are not functioning normally.
Follow these guidelines to troubleshoot the fans:
Check the fan LEDs and alarm LEDs on the craft interface.
If the red alarm LED on the craft interface lights, use the CLI to get information about
the source of an alarm condition:
If the CLI output lists only one fan failure, and the other fans are functioning normally,
the fan is most likely faulty and you must replace the fan tray.
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 a fan tray is removed, a yellow alarm and a red alarm occur.
The following conditions automatically cause the fans to run at full speed and also
trigger the indicated alarm:
A fan fails (red alarm).
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).
Alarm LEDs and Alarm Cutoff/Lamp Test Button on the MX480 Craft Interface on
page 29
Replacing the MX480 Fan Tray on page 160
Maintaining the MX480 Air Filter on page 116
Maintaining the MX480 Fan Tray on page 116
The DPCs are not functioning normally.
Monitor the green LED labeled
DPC is seated in an operating router.
The Routing Engine downloads the DPC software to it under two conditions: the DPC
is present when the Routing Engine boots Junos OS, and the DPC is installed and
requested online through the CLI or push button on the front panel. The DPC then runs
diagnostics, during which the
normally, the LED lights green steadily.
OK
Make sure the DPC is properly seated in the midplane. Check that each ejector handle
has been turned clockwise and is tight.
user@host> show chassis alarms
above the DPC on the craft interface as soon as a
OK
OK LED blinks. When the DPC is online and functioning
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