Juniper T640 Hardware Manual page 202

T640 Core Router Hardware Guide
Solution
172
During normal operation:
The blue LEDs light to indicate that the power supplies are functioning normally.
DC OK
The green CB ON and the blue
faceplate are on, indicating that the power source is good and the power supplies are
functional.
For a three-input 240-A DC power supply or four-input 240-A DC power supply:
The green INPUT PRESENT
good and the power supplies are functional.
Each
INPUT PRESENT
The CB ON LED is lit, indicating that the circuit breaker is on.
For a three-phase delta or wye AC power supply:
The green AC OK LED is lit, indicating that the power supply is receiving source AC
power.
The blue LED is lit, indicating that the power supply is functioning normally.
DC OK
To troubleshoot the T640 power system:
If the OVER TEMP LED on one of the power supplies lights, check the fans and air
1.
filters in the chassis to be sure they are functioning and providing sufficient airflow.
Check the display on the craft interface. The Junos OS constantly updates the screen
2.
with status information for each component. For more information about the display,
see "T640 Craft Interface Description" on page 41.
NOTE: On the display and in the CLI, the power supplies are referred to
as and
PEM0
NOTE: If the system temperature exceeds the threshold, the Junos OS
shuts down all power supplies so that no status is displayed on the craft
interface.
The Junos OS also can shut down one of the power supplies for other
reasons. In this case, the remaining power supply assumes the load, and
you can still view the system status through the CLI or display.
If a red alarm condition occurs, check the display on the craft interface to determine
3.
the source of the problem.
If the LED is not lit on one or both of the power supplies,
4. DC OK
DC OK LEDs on each two-input 160-A DC power supply
and the blue DC OK LEDs are on, the power source is
LED is lit, indicating that the input is receiving source DC power.
, from top to bottom.
PEM1
Copyright © 2010, Juniper Networks, Inc.