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Cisco Catalyst 4900M Switch Installation Guide
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Chapter 1 Troubleshooting the Installation
Problem Solving to the System Component Level
Problem Solving to the System Component Level
The key to success when troubleshooting the system is to isolate the problem to a specific system
component. The first step is to compare what the system
is
doing
to what it
should be doing
. Because a
startup problem can usually be attributed to a single component, it is more efficient to isolate the problem
to a subsystem rather than troubleshoot each separate component in the system.
The switch consists of the following subsystems:
•
Power supply—Includes the power supply and power supply cooling. (See the
Power Supply” section on page 1-4
•
Fan assembly system—The chassis fan assembly should operate whenever system power is on.
Usually, it continues to operate even when the environmental monitor shuts down the system
because of an overtemperature or overvoltage condition. (It will shut down for a power supply
shutdown.) You should be able to hear the fan assembly to determine whether or not it is operating.
If the FAN LED is orange and you determine that the fan assembly is not operating, you should
immediately contact a customer service representative. There are no installation adjustments that
you can make if the fan assembly does not function properly at the initial startup.
Identifying Startup Problems
When you connect the power cords to the Catalyst 4900M switch, follow these steps:
Step 1
Flip the power switches to the on position (AC powered systems only).
Step 2
Verify that power is available to the power supplied from the site AC or DC source. Flip breakers and
fuses if necessary.
Step 3
Listen for the system fan assembly. If you do not immediately hear the system fan assembly begin to
operate, see
“Troubleshooting the Power Supply” section on page 1-4
Step 4
If you determine that the power supplies are functioning normally and that the fan assembly is faulty,
contact a customer service representative. If the system fan assembly does not function properly at initial
startup, there are no installation adjustments that you can make.
LED Readings
LEDs indicate all system states in the startup sequence. By checking the LEDs, you can determine when
and where the system failed in the startup sequence. To check the LEDs, follow these steps:
Step 1
Compare the LED states to those listed in
