Hardware Troubleshooting 5-3
Problem Solving with Subsystems—Cisco7206 Router
Dial shelf processor cards includ e the following:
•Dial shelf controller card
•Modem cards
•Trunk cards
The following sections will help you is olate a problem withi n one o f these subsystems a nd direct you
to the appropriate troubleshooting section.
Problem Solving with Subsystems—Cisco7206 Router
The key to solving problems with the system is isolating the problem to a sp ec ific subsystem. The
first step in solving startup problems is to compare what the system is doi ng to what it should be
doing. Because a startup problem is usually caused by a single component, it is more efficient to
isolate the problem to a subsystem rather than to troubleshoot each component in the system. For
these troubleshooting procedures, consider the following subsystems:
•Power subsystem—This subsystem comprises the power suppli es, the e xternal powe r cable , and
the midplane.
•Cooling subsystem—The chassis fan tray is the single component in this subsystem. The fans
should be operating whenever system power is on. Replace the fan tray if you determine that a
fan is not functioning properly.
•Processor subsystem—This subsystem includes the I/O controller, network processing engine,
and all port adapters. The system memory and management functions resi de on the I/ O controller
and the network processing engine. The enabled L ED on e ach po rt ada pter in dic ates whe ther t he
port adapter is initialized. A port adapter that is partially installed in the midplane can cause the
system to hang and crash.
You can quickly verify that your new router shelf is properly installed and operative by observing
the router LEDs as described in the “Starting the Cisco 7206” section on page4-8.