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Cisco Catalyst 4900M Switch Installation Guide
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Chapter 4 Troubleshooting the Installation
Identifying Startup Problems
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 4-5.
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 Table 4-1:
