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Cisco 12404 Internet Router Installation and Configuration Guide
OL-11636-01
Chapter 4 Troubleshooting the Installation
Identifying Startup Problems
By checking the state of the LEDs on the power supplies and the alphanumeric
displays on the RP and line cards, you can determine when and where the system
failed in the startup sequence.
When you start up the system by turning on the power supply power switches, the
following should occur:
•
The two Green INPUT OK LEDs for the AC PEMs should go on
immediately; they should remain on as long as the system is receiving power
from the AC power source, and the power switch is in the on position. If
either of these LEDs does not go on, or if it goes off while the power switch
is still on, there could be a problem with either the power source, the internal
DC voltage –48 VDC that the power supplies distribute to the internal
components, or the cooling subsystem.
The Green INPUT OK LEDs indicate the status of the PEM and internal
DC voltages. These LEDs stay on when all of the following conditions are met:
•
AC power source voltage from an AC power source operating between
100-120 VAC, 15-Amp service in North America; and a range of 185-264
VAC, 10-Amp service, in an international environment.
•
Power supplies are providing the –48 VDC to internal components.
•
All internal DC voltages are within tolerance.
–
If the AC power source or any of the internal DC voltages exceed
allowable tolerances, the OUTPUT OK LED will not go on, or will go off
shortly after you turn on the power. Because both the RP (which use +2.5,
+3.3 and +5 VDC), and the fan tray assembly (which uses –48 VDC) are
required for operation, a problem with any of the internal DC lines can
prevent the system from starting up or continuing operation.
–
For example, if there is a problem with the –48 VDC line that supplies
the fan tray, the system will start up, but will also recognize that the fan
are not operating. The system will initiate a fan failure shutdown
sequence, display the appropriate warning messages, then shut down
after two minutes. If there is a problem with any of the other DC lines,
the RP will not be able to initialize the system software, so the system
might attempt to start up and fail during the boot sequence.
•
When the system is powered on, the fan tray, located at the side of the chassis,
immediately begins operating.
todd.book Page 17 Tuesday, November 27, 2007 6:02 PM