Juniper EX9208, Hardware Manual, Page: 320 / 396

Troubleshooting Power Supplies in an EX9200 Switch
Problem Description: 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 glow steady green.
•
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
must indicate that each of the power supplies is functioning normally:
user@switch>
show chassis environment pem
PEM 0 status:
State Online
Temperature OK
DC Output Voltage(V) Current(A) Power(W) Load(%)
48 12 576 36
PEM 1 status:
State Online
Temperature OK
DC Output Voltage(V) Current(A) Power(W) Load(%)
50 12 600 37
The output is of an EX9208 switch. The output is similar for all EX9200 switches.
If a power supply is not functioning normally, perform the following steps to diagnose
and correct the problem:
•
If a major 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, Junos OS shuts
down all power supplies so that no status is displayed.
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 switch ,
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.
•
Verify that the source circuit breaker has the proper current rating. Each power supply
must be connected to a separate source circuit breaker.
Copyright © 2017, Juniper Networks, Inc. 296
EX9208 Switch Hardware Guide