All LEDs on One Supply are Off or LED States are not Correct

If either of the following conditions apply, perform the diagnostic procedure that follows:

• The LEDs on one power supply are all off, but the LEDs on the other supply indicate that it is functioning properly.
• The LED states on one or both supplies indicate a problem: the green LED labeled OK is not lit and the red LED labeled FAIL is lit.

Perform the following steps to diagnose and correct the problem:

1. Check the red alarm LED on the craft interface:

• If it is lit, issue the following CLI command for more information about the source of an alarm condition:

user@host> show chassis alarms

For a list of messages that can appear, see Hardware and Interface Alarm Messages.

A common cause of power supply shutdown is that the temperature of the power supply or another router component has exceed the maximum temperature.

• If the red alarm LED is not lit, check that the power switch is in the ON ( | ) position on the power supply faceplate.

2. Replace the faulty power supply with a spare. For instructions, see Replace an AC Power Supply and Replace a DC Power Supply. If the LEDs light correctly on the spare, the original power supply is faulty. Return it to Juniper Networks for replacement, as described in Return the Router or Its Components.
3. If the spare power supply also does not work, connect the router to a different power source. You might also try replacing the power cord (on an AC-powered router) or power cable (on a DC-powered router). For instructions, see Disconnect and Connect AC Power and Disconnect and Connect DC Power.

If you cannot determine the cause of the problem or need additional assistance, see Juniper Networks Technical Assistance Center.