Cisco Systems 901 Troubleshooting the Power and Cooling Systems, Environmental Reporting Features

Appendix A Troubleshooting

Problem Solving

•Cables—Ensure that the external cables connecting the router to the network are all secure.

Troubleshooting the Power and Cooling Systems

See Table A-1for information to help you isolate the problem.

Table A-1	Troubleshooting the Power and Cooling Systems
Symptom		Possible Cause	Corrective Action
The power (labeled PWR) LED		The power source is not	Check the DC input.
on the front panel is not on.		connected properly.	Check the DC source.
The router shut down after being		The cause is environmental.	Check for an environmentally
on for only a short time.			induced shutdown. (See
			“Environmental Reporting
			Features” section on page A-2).
		The fans do not work; the router	Check the fans.
		overheats and shuts down.
		The chassis intake and exhaust	Check the chassis intake and
		vents are obstructed.	exhaust vents for obstructions.
			Clear any obstructions.
		Installation does not meet	Check the environmental site
		environmental site	requirements in the “System
		requirements.	Specifications” on page -7.
The router partially boots, but		There is a possible power supply	Check the power LED on the
the LEDs do not light.		failure.	front panel of the router. If the
			LED is on, the power supply is
			functional. If the LED is off, refer
			to the Cisco Information Packet
			for warranty information or
			contact customer service.

Environmental Reporting Features

The Cisco ASR 901 router has a temperature sensor to detect over temperature conditions inside the chassis. The over temperature detection triggers an alert at 70°C. This condition is reported to the processor as an interrupt, where software takes action to generate the appropriate alarms. If the router reaches a temperature of 85°C, the power supply will cycle to prevent the router from exceeding that temperature while being powered up state. See Table A-2for help in interpreting environmental reporting features.

Cisco ASR 901 Series Aggregation Services Router Hardware Installation Guide

A-2 OL-23778-01