Troubleshooting the Cisco 4000 Series Integrated Services Routers Power and Cooling Systems
This chapter describes how to troubleshoot the Cisco 4000 Series Integrated Services Routers (ISRs) power and cooling systems.
Both the system LED and the fans can help you troubleshoot a power problem. Check the following items to help isolate the problem:
Normal Indications
Fault Indications
This is a condensed listing of LED states. For the complete listing see “LED Indicators”.
Check the following symptoms to locate or eliminate faults in the power and cooling systems:
– If the LED is solid green and continuous, the router has booted and the software is functional.
– If the LED is blinking amber, the system BIOS/ROMMON is in the process of booting. If it continues blinking for longer than 2 minutes, there might be a problem loading ROMMON.
– If the LED is off, the system is not out of reset or the BIOS image is not loadbale.
– If the LED is amber, BIOS/ROMMON has completed booting and system is at ROMMON prompt or booting platform software. If it is there for a very long time, it indicates that the router is sitting at a ROMMON prompt which could mean a problem loading the Cisco IOS-XE image.
– If yes, the power system is functioning.
– If yes, the router is receiving power. The fan is connected directly to the DC outputs of the power supply.
– If no, check the power source and power cable.
– Check for an environmentally induced shutdown.
– Check the environmental site requirements in “General Site Requirements”.
– Check for a power supply failure by inspecting the PWR LED on the front panel of the router. If the PWR LED is blinking or continuously green, the power supply is functional.
– If the PWR LED is not on, refer to “Obtaining Documentation and Submitting a Service Request” for warranty information, or contact customer service.
Environmental Reporting Features
If the router is operating at an abnormally high temperature, consider the following causes:
Take steps to correct the problem. Refer to the Preparing for Router Installation chapter in the H ardware Installation Guide for the Cisco 4451-X Integrated Servcies Router..
Online Troubleshooting Resources
In addition to following the subsystems approach to troubleshooting, a variety of online troubleshooting resources are available.
Cisco.com registered users can access various troubleshooting tools such as Software Advisor, Cisco IOS Error Message Decoder Tool, and Output Interpreter Tool after logging in at http://www.cisco.com/en/US/support/tsd_most_requested_tools.html.
General Troubleshooting Tips
Table 2-1 lists general troubleshooting tips.
Troubleshooting Using a Subsystem Approach
To solve a system problem, try to isolate the problem to a specific subsystem. Compare current router behavior with expected router behavior. Because a startup issue is usually attributable to one component, it is most efficient to examine each subsystem, rather than trying to troubleshoot each router component.
For troubleshooting purposes in this chapter, the router consists of the following subsystems:
AC input power supplies, also called power supply units (PSUs). The Cisco 4000 Series Integrated Services Routers is shipped with fully redundant PSUs installed in the chassis.
- Processor subsystem—The Cisco 4000 Series Integrated Services Routers has onboard processors. The LED is blinking yellow until the ROMMON hass booted. If the board has booted ROMMON successfully, the LED is yellow. If operation software (IOS) has downloaded successfully, the LED is green.
- Cooling system—Consists of four fans in the Cisco 4000 Series Integrated Services Routers system board. Each PSU has its own fans.
Normal Router Startup Sequence
You can generally determine when and where the power supply failed during the startup sequence by checking the status LEDs on the power supply modules.
In a normal router startup sequence, the following sequence of events and conditions occur:
1. The fan in each PEM receives power and begins drawing air through the power supply. The power supply PWR OK indicator is on and reflects power supply status.
2. As the power on and boot process progresses for the Cisco 4000 Series Integrated Services Routers, the status is indicated by LEDs.
Troubleshooting the Power Subsystem
Use the information in Table 2-2 to isolate problems with the power system.
Troubleshooting the Cooling Subsystem
Use the information in Table 2-3 to isolate problems with the cooling subsystem.
Troubleshooting Upgrade-Related Problems
See Table 2-4 below for troubleshooting tips during an upgrade: