M160 Internet Router Hardware Guide
Excessive systemtemperature is almost always caused by excessiveenvironmental
temperature. Correct the environmental tem perature before powering on the router.
All LEDs on One Supply Are Off or LED States Are not Correct
If either of the following conditions applies, perform the diagnostic
procedure described followingthe list of conditions:
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 indicatea problem:
On the enhanced powersupply, the green LED labeled CB ON is not lit and
the amber LED labeled CB OFF is lit, or the blue LED labeled OUTPUT OK
is blinking or is not lit.
On the original power supply, the green LED labeled CB ON is not lit and
the amber LED labeled CB OFF is lit, or the amber LED labeled NO AIRFLOW
is lit, or the blue LED labeled OUTPUT OK is blinking or is not lit.
Perform the followingsteps to diagnose and correct the problem:
1. Check the red alarm LED on the craftinterface:
If it is lit, read the message on the craft interface LCD. The display
reports the number of alarm conditions and the sourceof each alarm,
as described in “LCD Alarm Mode” on page 30. For a list of messages,
see “Chassis and Interface AlarmMessages” on page 209. Issue the
following CLI command form oreinformation about the cause of an
alarm condition:
user@host> show chassis alarms
NOTE: The messages in the craft interfaceLCD and the output from CLI show
commands refer to the power supply on the right as PEM 0 and the power supply
on the left as PEM 1.
A common cause of power supply shutdown is that the temperature of the
power supply or another routercomponent has exceed the maximum
limit.
If the red alarm LED is not lit,check that the power switch is in the ON (|)
position. The switches are on the circuit breakerbox.
2. Replace the faulty power supply with a spare. For instructions, see “Replacing
a PowerSupply” on page 197. If the LEDs light correctly on the spare,the
original power supply is faulty. Return it to Junip er Networks for replacement,
as described in “Contacting Customer Supportand Returning Hardware”
on page 255.
216 Troubleshootingthe Power System