Troubleshooting The Power Subsystem; Troubleshooting The Ac Power Subsystem - Cisco 12404 Installation And Configuration Manual

Troubleshooting the Power Subsystem

Troubleshooting the Power Subsystem

Troubleshooting the AC Power Subsystem

Cisco 12404 Internet Router Installation and Configuration Guide
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When the system is powered on, the alphanumeric LED displays on the RP
•
indicate the following.
The left display indicates which RP software component is running.
–
The right display indicates the phase of the boot process that is currently
–
occurring.
The power subsystem in the Cisco 12404 router consists of the following
components.
• AC PEMs
DC PDUs and PEMs
•
Processor subsystem
•
Route Processor
•
Line cards
•
The AC PEMs provide –48 VDC OUTPUT. The +5 VDC OUTPUT from the CSF
powers the MBus module on each card in the system. The MBus module, in turn,
control the DC-DC converters also present on each card in the system. The
DC-DC converter takes –48 VDC from the power supply and converts it into +2.5,
+3.3 and +5 VDC, which is distributed to the card circuitry.
Begin checking the power subsystem by first looking at the three LEDs on the
power supply faceplate. The INPUT OK LED on an AC PEM goes on when AC
power is applied, The OUTPUT OK LED goes on when the PEM power switch is
turned on.
The amber OUTPUT FAIL LED is normally off, but goes On if the PEM detects
a fault.
The AC PEM are monitored by the MBus module and the RP for over- or
undervoltage and over- or undercurrent conditions.
Continue by checking the following to help isolate the problem with the power
subsystem.
Chapter 4 Troubleshooting the Installation
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