Troubleshooting the SLB Switch

This appendix provides the following information on how to troubleshoot the SLB switch installation:

If your SLB switch has problems starting up, use the information in this appendix to help isolate the cause. Problems with the initial startup are often caused by poor or improper connections. Although temperature conditions above the maximum acceptable level rarely occur at initial startup, environmental monitoring functions are included.

To configure or enable the interfaces, refer to the Catalyst 4840G Software Feature and Configuration Guide.

Verifying Start-up Conditions Operations

Verify the following conditions after the system starts up:

Power supplies are operating properly.
System fan assembly is operating.
System software is booting successfully.

If any of these conditions are not met, use the procedures in this chapter to isolate and, if possible, resolve the problem. To configure the software, refer to the Catalyst 4840G Software Feature and Configuration Guide.

Solving Problems at the Component Level

The key to success when troubleshooting the SLB switch is to isolate the problem to a specific switch component. The first step is to compare what the SLB switch is doing to what it should be doing. Because a startup problem is usually attributed to a single component, it is more efficient to isolate the problem to a subsystem rather than troubleshoot each separate component in the switch.

The SLB switch consists of the following subsystems:

The power supplies and power supply fans operate whenever system power is on (see the "Troubleshooting the Power Supply" section).
The chassis fan assembly operates when the system power is on. The fan usually continues to operate even when the environmental monitor shuts down the SLB switch because of an overtemperature or overvoltage condition (although it does shut down for a power supply shutdown).

The following are simple checks you can make to determine if there is a fan problem:

Check if the software is reporting a temperature problem.
Listen to the fan assembly to determine if it is operating.
Check for any obstructions restricting airflow through the switch.

If you determine that the fan is not operating, contact a customer service representative.

Identifying Startup Problems

LEDs indicate all switch states in the startup sequence. By checking the LEDs, you can determine when and where the switch failed in the startup sequence.

Perform the following steps when you connect the power cords to the SLB switch:

Step 1 Listen for the system fans to begin to operate. If they do not, see the "Troubleshooting the Power Supply" section. If you determine that the power supplies are functioning normally and that the fans are faulty, contact a customer service representative. If the SLB switch fans do not function properly at initial startup (there are no installation adjustments that you can make), contact a customer service representative.

Step 2 Check the power supply LED. The power supply LED turns green immediately when power is on. The LED remains green during normal SLB switch operation. If the LED turns red, see the "Troubleshooting the Power Supply" section.

Step 3 Check the LEDs on the front panel. See the "Front Panel LEDs" section for LED descriptions.

Step 4 Verify that the terminal is set correctly and that it is connected properly to the console port if the boot information and switch banner are not displayed.

Step 5 Contact a customer service representative for instructions if a status LED indicates a failure.

Troubleshooting the Power S upply

To help isolate a power problem, follow these steps:

Step 1 Check the power supply LED.

If the LED is off or if the LED is red, unplug the power cord, and then plug the power cord back in.
If the LED remains off, check the AC source or the power cable for problems.

Step 2 Connect the power cord to another power source if one is available.

If the LED comes on, the problem is the first power source.
If the LED is off after you connect the power supply to a new power source, replace the power cord.
If the LED still fails to light when the switch is connected to a different power source with a new power cord, the power supply is probably faulty.

Step 3 Check the LED on the second power supply.

If the LED is not green or on, repeat the previous procedure to troubleshoot the second power supply.
If you are unable to resolve the problem, contact a customer service representative for instructions.

Note If you are using a Cisco RPS, do not apply power to the RPS and the Catalyst 4908G-Layer 3 switch. Disconnect power from the switch's internal power supply before turning the power on for the RPS. The RPS contains multiple power supplies for redundant power protection. Refer to the Cisco RPS documentation for installation and configuration details.

Contacting Custom er Service

If you are unable to solve a startup problem after using the troubleshooting suggestions in this chapter, contact a customer service representative for assistance and further instructions. Before you call, have the following information ready to help your service provider assist you as quickly as possible:

Date you received the SLB switch
Chassis serial number (located on a label on the right of the rear panel of the chassis)
Type of software and release number
Maintenance agreement or warranty information
Brief description of the problem
Brief explanation of the steps you have already taken to isolate and resolve the problem

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