• Supported Platforms
• MX80 Routers

• Related Topics
• MX80 Power System Description
• MX80 Power Supply LED
• Maintaining the MX80 Power Supplies
• Replacing an MX80 AC Power Supply
• show chassis environment pem
• show chassis alarms

Troubleshooting the MX80 Power Supplies

Problem

The power supply is not functioning normally.

Solution

• Check the LEDs on each power supply faceplate. If a power supply is correctly installed and functioning normally, the status LED on the power supply lights 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
    DC Output:                 OK
  PEM 1 status:
    State                      Online
    Temperature                OK
    DC Output:                 OK
  

• 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 AC input switch or DC circuit breaker is in the on ( | ) position and 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 router 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 LED indicates that the power supply is not operating normally, the power supply is the source of the problem. Replace the power supply with a spare.