Troubleshooting The Rp - Cisco Gigabit Switch Router 12008 Installation And Configuration Manual

The MBus module processor begins to operate as soon as power is applied to the system.
The MBus processor determines what type of card it is mounted on and whether it should
turn on the card's DC-DC converter. The master MBus module on the RP turns on card
power after a brief delay; the MBus modules on the line cards delay turning on power until
they receive a command to do so from the RP master MBus module.
To operate at all, a minimally configured Cisco 12008 must have a RP. However, the system
can operate without any line cards, as long as no line card is in partial contact with the
backplane pins.
A line card that is only partially inserted into the backplane sends incomplete signals to the
RP, which can cause the system to hang. First ensure that the RP is installed properly and
that the system software has initialized successfully. Then, if necessary, you can
troubleshoot the individual line cards.
A power-on self-test (POST) runs immediately at power-on to determine the condition of
RP memory. The results of this test appear in the alphanumeric display as a pass/fail
message.

Troubleshooting the RP

To isolate a problem with the RP, assess the following:
•
Are both RP alphanumeric displays on?
— If both displays are off, the RP may not be fully seated in the backplane, there may
— If both displays are on, check the message being displayed.
be a problem with the MBus module on the RP, or the system power supply may be
off.
The two alphanumeric displays are powered separately. The top display receives
power from the onboard DC-DC converter of the RP. The bottom display is
powered directly from the MBus by means of the power supply(ies). Thus, even if
the RP has not powered up, the bottom display could be on.
As soon as the DC-DC converter is turned on by the MBus module, the RP
processor begins the boot process. Status messages are displayed as the boot
process continues (see Table 5-2).
Troubleshooting the Processor Subsystem
Troubleshooting the Installation 5-13