Juniper Networks MX480 - Manual (Page 183)

• Replacing an MX480 MIC on page 208
Troubleshooting the MX480 Power System
Problem The power system is not functioning normally.
Solution Check the LEDs on each power supply faceplate. •
• If an AC power supply is correctly installed and functioning normally, the AC OK and
DC OK LEDs light steadily, and the PS FAIL LED is not lit.
• If a DC power supply is correctly installed and functioning normally, the PWR OK ,
BRKR ON , and INPUT OK LEDs light green steadily.
• Issue the CLI show chassis environment pem command to check the status of installed
power supplies. As shown in the sample output, the value Online in the rows labeled
State indicates that each of the power supplies is functioning normally:
user@host> show chassis environment pem
PEM 0 status:
State Online
Temperature OK
AC Input: OK
DC Output Voltage(V) Current(A) Power(W) Load(%)
59 0 0 0
PEM 1 status:
State Online
Temperature OK
AC Input: OK
DC Output Voltage(V) Current(A) Power(W) Load(%)
59 18 1062 42
If a power supply is not functioning normally, perform the following steps to diagnose
and correct the problem:
• If a red alarm condition occurs, issue the show chassis alarms command to determine
the source of the problem.
• If all power supplies have failed, the system temperature might have exceeded the
threshold, causing the system to shut down.
NOTE: If the system temperature exceeds the threshold, the Junos OS
shuts down all power supplies so that no status is displayed.
The Junos OS also can shut down one of the power supplies for other
reasons. In this case, the remaining power supplies provide power to the
router, and you can still view the system status through the CLI or display.
• Check that the DC circuit breaker ( — ) or AC input switch ( | ) is in the on position and
that the power supply is receiving power.
159 Copyright © 2013, Juniper Networks, Inc.
Chapter 13: Troubleshooting MX480 Hardware Components