Cisco Systems 7401ASR Troubleshooting the I/O Subsystem, Troubleshooting the Processor Subsystem

Chapter 5 Troubleshooting

Problem Solving Using a Subsystems Approach

Troubleshooting the I/O Subsystem

The procedures in this section assume that you have not made changes to your configuration file.

If the Cisco 7401ASR router I/O LEDs do not go on as expected (see the “Identifying Startup Problems” section on page 5-3), check the following items to help isolate the problem:

Table 5-3 Troubleshooting the I/O Subsystem

Symptom	Possible Cause	Possible Solution
LEDs remain off when the system power	Power supply or	If the LEDs stay off, first see the “Troubleshooting the
switch is turned on.	cooling subsystem is	Power Subsystem” section on page 5-4and the
	faulty.	“Troubleshooting the Cooling Subsystem” section on
		page 5-5to ensure that both the fans and the power supply
		are functioning properly.
Power supply and fans appear	The improperly	Reseat the port adapter, tighten the screw of the port
operational, but none of the I/O LEDs	connected port	adapter latch, and then restart the system.
are on.	adapter has
	indefinitely paused
	the system.
The prior configuration—native Gigabit	The media-type	See Chapter 3, “Starting and Configuring,” the
Ethernet or the Fast	command was not	“Configuring the Native Gigabit Ethernet and Fast
Ethernet/Ethernet—LEDs remain on	used when changing	Ethernet/Ethernet Interfaces” section on page 3-15.
after configuring the ports to change the	the configuration of
configuration from one Ethernet type to	these ports.
the other.

Troubleshooting the Processor Subsystem

The processor subsystem comprises the system board and the port adapter. A port adapter that is partially connected to the system board sends incomplete signals to the processor, which faults the PCI bus and causes the system to pause indefinitely. Therefore, first ensure that the system software has initialized successfully and then check to see if the port adapter is fully connected.

Troubleshooting the Port Adapter or Service Adapter

Check the following to help isolate a problem with the port adapter or service adapter:

Table 5-4 Troubleshooting the Port Adapter or Service Adapter

Symptom		Possible Cause	Possible Solution
Port adapter or		The port adapter or	Reseat the adapter in its slot (you do not have to turn off the system power when
service adapter		service adapter might	removing or replacing port adapter and service adapters). After the system
ENABLE LED is		have pulled away	reinitializes the interfaces, the ENABLE LED on the port adapter or service
off.		from the system	adapter should go on.
		board.	If the ENABLE LED remains off, the system detected a processor hardware
			failure. (This LED should be on in normal operation.) Contact a service
			representative for instructions.
	Cisco 7401ASR Installation and Configuration Guide
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