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.
• Verify that the AC power cord or DC power cables from the power source to the switch are not
damaged. If the insulation is cracked or broken, immediately replace the cord or cable.
• Connect the power supply to a different power source with a new power cord or power cables. If the
power supply status LEDs indicate that the power supply is not operating normally, the power supply
is the source of the problem. Replace the power supply with a spare.
Troubleshoot Temperature Alarms in EX Series Switches
IN THIS SECTION
149