Troubleshooting the TX Matrix Power System
Problem
The following alarms, LEDs, command output, and conditions
indicate a problem with the power system:
- The yellow CB TRIP LED lights on the two-input
160-A power supply faceplate to indicate that the power supply detects
a fault (the power supply fails, does not have sufficient airflow,
is going through a startup test, or is not properly inserted).
- The blue DC OK LED blinks on the three-input
240-A power supply faceplate to indicate that the power supply detects
a fault (the power supply fails, does not have sufficient airflow,
is going through a startup test, or is not properly inserted).
- The yellow OVER TEMP LED lights on the power
supply faceplate when the two-input 160-A power supply or the three-input
240-A power supply is not receiving enough airflow to maintain proper
temperature.
During normal operation:
- If the green CB ON and the blue DC OK LEDs on each two-input 160-A power supply faceplate are on, the
power source is good and the power supplies are functional.
- The CB ON LED on the faceplate of each
two-input 160-A power supply faceplate or three-input 240-A power
supply lights when the circuit breaker is functioning.
- If the green INPUT PRESENT and the blue DC OK LEDs are on each three-input 240-A power supply, the power source
is good and the power supplies are functional.
- The INPUT PRESENT LEDs light on each three-input
240-A power supply when the input is receiving source DC power.
Solution
To verify that a power supply is functioning normally:
Check the LEDs on each two-input 160-A power supply faceplate.
- If the green CB ON and the blue DC OK LEDs are on, the power source is good and the power supplies are
functional.
- The CB ON LED on the power supply lights
when the circuit breaker is functioning.
- The DC OK LED lights when the power supply
is receiving source DC power.
- The yellow CB TRIP LED lights when the power
supply detects a fault (the power supply fails, does not have sufficient
airflow, is going through a startup test, or is not properly inserted).
- The yellow OVER TEMP LED lights when the
power supply is not receiving enough airflow to maintain proper temperature.
Check the LEDs on each three-input 240-A power supply
faceplate.
- If the green INPUT PRESENT and the blue DC OK LEDs are on, the power source is good and the power supplies are
functional.
- The INPUT PRESENT LED lights when the input is
receiving source DC power.
- The CB ON LED on the power supply lights
when the circuit breaker is on.
- The blue DC OK LED blinks when the power
supply detects a fault (the power supply fails, does not have sufficient
airflow, is going through a startup test, or is not properly inserted).
- The yellow OVER TEMP LED lights when the
power supply is not receiving enough airflow to maintain proper temperature.
- Check the display on the craft interface. The Junos OS
constantly updates the screen with status information for each component.
 | Note:
On the display and in the CLI, the power supplies are
referred to as PEM0 and PEM1, from top to bottom. |
If a power supply is not functioning normally, perform the following
steps to diagnose and correct the problem:
- If the DC OK power supply LED is off, check
the red alarm LED on the craft interface. The Junos OS monitors the
system temperature, and if it exceeds a certain limit, the software
triggers a red alarm, a condition that shuts down the power supplies.
- If a red alarm condition occurs, check the display on
the craft interface to determine the source of the problem.
 | 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 supply assumes the
load, and you can still view the system status through the CLI or
display. |
- If the DC OK power supply LED is off and
no red alarm condition exists, check that the circuit breaker is switched
to the on position (|).
- Verify that the source circuit breaker has the proper
current rating. Each input on each power supply must be connected
to a separate power source.
- Verify that the power cables from the power source to
the TX Matrix router are not damaged. If the insulation is cracked
or broken, immediately replace the cable.
- Connect the power supply to a different power source with
a new power cable. If the power supply DC OK LED still
does not light, the power supply is the source of the problem. Replace
the power supply with a spare.
- If the DC OK LED on the installed spare
lights, the replaced power supply is faulty, and you should return
it for replacement, as described in Returning a Hardware Component to Juniper Networks, Inc..
- If the OVER TEMP LED on one of the power
supplies lights, check the fans and air filters to be sure they are
functioning and providing sufficient airflow through the chassis.
- If you cannot determine the cause of the problem or need
additional assistance, see Contacting Customer Support.
Published: 2011-12-19