Chapter 4 Troubleshooting the Installation
Problem Solving with Subsystems
4-14
Cisco 12006 and Cisco 12406 Router Installation and Configuration Guide
OL-11497-03
Step 14 Exit global configuration mode by entering Ctrl-Z.
router(config)# Ctrl-Z
router#
Step 15 Reboot the router and use the recovered password with the enable command to
gain access to the router.
Problem Solving with Subsystems
The key to solving problems in the system is to try to isolate the problem to a
specific subsystem. The first step in solving startup problems is to compare what
the system is doing to what it should be doing. Because a startup problem is
usually attributable to a single component, it is more efficient to first isolate the
problem to a subsystem rather than troubleshoot each component in the system.
For troubleshooting purposes, Cisco 12006 and Cisco 12406 Routers consist of
the following subsystems:
• Power subsystem—Includes the following components:
–
AC-input or DC-input power distribution unit (PDU)
–
AC-input power supplies or DC-input power entry modules (PEMs).
Cisco 12006 and Cisco 12406 Routers can be configured for source AC
or source DC power. (You can not mix and match AC and DC power.)
–
Chassis backplane power distribution. The –48 VDC power from the
power supplies is transferred to the chassis backplane, which distributes
–48 VDC power to the cards in the card cages through the backplane
connectors. The blower module receives power from the chassis
backplane and passes MBus data back to the chassis backplane through
a PDU connector.
DC-to-DC converters on the two alarm cards convert –48 VDC to
+5 VDC and put it back on the chassis backplane, where it is picked up
to power the MBus modules on other cards and the blower module.
–
DC-to-DC converters. Each card in the router is equipped with DC-to-DC
converters. These converters are controlled by the MBus module on each
card. The DC-to-DC converters take –48 VDC and convert it into the
voltages required by the card circuitry.