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This chapter contains instructions to help installers and technicians troubleshoot hardware installation. The chapter identifies and describes key software commands to help cable administrators and support engineers use the command-line interface (CLI) to troubleshoot the system.
The chapter includes the following sections:
Figure 5-1 shows the general troubleshooting strategy described in this chapter to troubleshoot the hardware. Refer to this chart, as necessary, to follow the steps to isolate hardware problems to a specific subsystem; then resolve the problem if possible.
If you are unable to easily solve the problem, contact a customer service representative for assistance and further instructions. Provide the representative with the following information:
For instructions to troubleshoot the system using CLI commands, refer to the "Troubleshooting the Headend System" section.
The key to solving problems with the system is isolating the problem to a specific subsystem. The first step in solving startup problems is to compare what the system is doing to what it should be doing. Because a startup problem is usually caused by a single component, it is more efficient to first isolate the problem to a subsystem rather than troubleshoot each component in the system. For these troubleshooting procedures, consider the following subsystems:
The following sections will help you isolate a problem to one of these subsystems and direct you to the appropriate troubleshooting section.
Startup problems are commonly due to the source power or to a board (network processing engine, I/O controller, port adapter, or cable modem card) that is dislodged from the midplane. Although an overtemperature condition is unlikely at initial startup, the environmental monitoring functions are included in this chapter because they also monitor internal voltages.
When you start up the Cisco uBR7200 series universal broadband router for the first time, you should observe the startup sequence described in the "Powering On the Cisco uBR7200 Series" section. This section contains a more detailed description of the normal startup sequence and describes the steps to take if the system does not perform that sequence as expected.
With the exception of the fan tray and network processing engine, LEDs indicate all system states in the startup sequence. By checking the state of the LEDs, you can determine when and where the system failed in the startup sequence. Use the following descriptions to isolate the problem to a subsystem, then proceed to the appropriate sections to try to resolve the problem.
When you start up the system by turning on the power supply switch, the following should occur:
1. You should immediately hear the fans operating. If not, proceed to the "Troubleshooting the Headend System" section. If you determine that the power supply is functioning normally and that a fan is faulty, contact a customer service representative. If a fan does not function properly at initial startup, there are no installation adjustments that you should make.
3. The LEDs on the I/O controller should go on as follows:
a. The IO power OK LED goes on immediately and indicates that the I/O controller is receiving DC power from the universal broadband router midplane. This LED goes on during a successful boot and remains on during normal operation of the Cisco uBR7200 series.
b. The enabled LED goes on after the IO power OK LED and indicates that the network processing engine and the I/O controller are enabled for operation by the system; however, it does not mean that the Fast Ethernet port on the I/O controller is functional or enabled. This LED goes on during a successful boot and remains on during normal operation of the Cisco uBR7200 series.
c. The FE enabled LED goes on after the enabled LED and indicates that the Fast Ethernet port on the I/O controller is initialized and enabled for operation by the system. This LED goes on during a successful boot and remains on during normal operation of the Cisco uBR7200 series.
d. The FE link LED goes on only when the Fast Ethernet port on the I/O controller is receiving a carrier signal from the network. This LED remains off during normal operation of the Cisco uBR7200 series unless there is an incoming carrier signal, and does not indicate startup problems.
e. The slot 1 and slot 2 LEDs go on after the enabled LED and indicate which Personal Computer Memory Card International Association (PCMCIA) slot is in use. During a successful boot, these LEDs go on and remain on if a Flash memory card is present in the slot. These LEDs also blink when either slot is being accessed by the system. These LEDs do not indicate startup problems.
4. The enabled LED on each port adapter goes on when the network processing engine completes its initialization of the port adapter for operation. The enabled LED indicates that the port adapter is receiving power and has been recognized by the network processing engine; it does not indicate the state of the individual interfaces on the port adapters. If an enabled LED fails to go on, proceed to the "Troubleshooting Port Adapters" section.
5. The enable LED on the clock card goes on when the network processing engine completes its initialization of the clock card for operation. The enable LED indicates that the clock card is receiving power and has been recognized by the network processing engine; it does not indicate the state of the primary and/or secondary interfaces on the clock card. If the enable LED fails to go on, proceed to the "Troubleshooting the Cisco Cable Clock Card" section.
6. The enabled LED on each cable modem card goes on when the network processing engine completes its initialization of the cable modem card for operation. The enabled LED indicates that the cable modem card is receiving power and has been recognized by the network processing engine; it does not indicate the state of the individual interfaces on the cable modem card. If an enabled LED fails to go on, proceed to the "Troubleshooting Cable Modem Cards" section.
7. When all LEDs go on to indicate that the system has booted successfully, the initial system banner should be displayed on the console screen. If it is not displayed, refer to the "Console and Auxiliary Port Connection Equipment" section to verify that the terminal is set correctly and that it is properly connected to the I/O controller's console port.
Check the following to help isolate a problem with the power subsystem:
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Caution When the input power to a Cisco uBR7200 series universal broadband router power supply is disconnected or lost, the power supply will enter a reset cycle for 10 seconds. Wait at least 10 seconds or move the power switch from one position to the other to restart the power supply. For example, if the power supply was ON when the power was disconnected or lost, move the power switch to the OFF position then back to the ON position. If you do not wait the full 10 seconds or move the power switch from one position to the other, the power supply will not restart. |
If you are unable to resolve the problem or you determine that either a power supply or chassis connector is faulty, contact a service representative for instructions.
Check the following to help isolate a problem with the cooling system:
Queued messages: %ENVM-1-SHUTDOWN: Environmental Monitor initiated shutdown
The processor subsystem comprises the I/O controller, network processing engine, all port adapters, the clock card, and all cable modem cards. The I/O controller and network processing engine are required system components. The system cannot operate unless the I/O controller and network processing engine are installed properly; however, the system can operate without any port adapters or cable modem cards installed as long as none are in partial contact with the midplane pins. A port adapter or cable modem card that is partially connected to the midplane will send incomplete signals to the processor, which will fault the peripheral component interconnect (PCI) bus and cause the system to hang. Therefore, first ensure that the I/O controller and the network processing engine are installed properly and the system software has initialized successfully. Then, if necessary, you can troubleshoot individual port adapters, clock card, and cable modem cards.
If the I/O controller LEDs do not go on as expected (refer to the "Identifying Startup Problems" section), check the following items to help isolate the problem:
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Caution When the input power to a Cisco uBR7200 series power supply is disconnected or lost, the power supply will enter a reset cycle for 10 seconds. Wait at least 10 seconds or move the power switch from one position to the other to restart the power supply. For example, if the power supply was ON when the power was disconnected or lost, move the power switch to the OFF position then back to the ON position. If you do not wait the full 10 seconds or move the power switch from one position to the other, the power supply will not restart. |
If the I/O controller enabled LED does not go on as expected, make sure the power to the universal broadband router is turned OFF, reseat the network processing engine in its slot, and restart the Cisco uBR7200 series universal broadband router.
If the enabled LED remains off, the system detected a processor hardware failure. (This LED should be on in normal operation.) Contact a service representative for instructions.
Check the following to help isolate a problem with the port adapters:
Check the following to help isolate a problem with the clock card:
Check the following to help isolate a problem with the cable modem cards:
If the CMTS has not been properly set up to support digital data, the Cisco uBR7200 series universal broadband router might start up, but fail to support data transmission. This chapter provides general tips to troubleshoot the system using CLI commands.
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Note Also, refer to "Connecting and Configuring the Cable Headend," for detailed information on the setup and tuning of the cable plant required to support digital data transmission. |
You can use a cable modem, such as the Cisco uBR904 or Cisco uBR924 cable access router, to verify the downstream signal originating from a Cisco uBR7200 series universal broadband router. The Cisco uBR904 and Cisco uBR924 cable access routers are equipped with 64- and 256-QAM receivers that require only minimal setup. Configure the Cisco uBR900 series according to DOCSIS practises.
To verify the downstream signal originating from the Cisco uBR7200 series:
Step 2 Scan the output for the value corresponding to the "SNR_estimate" variable. If this value is at least 35 dB, then you have an optimized signal. If the value is less than 34 dB, then you must adjust the upconverter at the cable headend.
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Note The exact value displayed will vary from cable modem to cable modem, however, the values collected from measurement to measurement on the same modem will be consistent. |
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Tips |
Posted: Tue Mar 28 08:55:20 PST 2000
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