Chapter 5: Troubleshooting

Your Cisco uMG9820 went through extensive testing before leaving the factory. However, if you encounter problems starting the Cisco uMG9820, use the information in this chapter to help isolate the cause of the problems. The procedures in this chapter cover troubleshooting the initial system startup. In addition, references to CLI commands are provided to troubleshoot GE and FE ports, as well as QAM channels.

Overview

This section describes the troubleshooting methods used in this chapter and describes how the Cisco uMG9820 is divided into subsystems for more efficient problem solving.

Figure 5-1 shows the general troubleshooting strategy described in this chapter. Refer to this chart, as necessary, to follow the steps to isolate problems to a specific subsystem.

Before You Call for Technical Assistance

If you are unable to solve the problem easily, contact a Cisco customer service representative for assistance and further instructions. (See Obtaining Technical Assistance, page xvi.)

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Brief explanation of the steps you have taken to isolate and resolve the problem

Creating an Information Dump

It can be helpful to Technical Assistance if you prepare an information dump before contacting them. To create this information dump, do the following:

Step 3

Enter the following command:
uMG9820(debug)#infodump tftp://server-ip-address/filename

Step 4

The information dump is created and saved to the specified TFTP server.

Solving Startup Problems by Using a Subsystems Approach

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 isolate the problem to a subsystem rather than to troubleshoot each component in the system. For these troubleshooting procedures, consider the following subsystems:

Startup problems are commonly due to the source power or to a port adapter that is dislodged from the Cisco uMG9820. Although an overtemperature condition is unlikely at initial startup, the environmental monitoring functions are included in this chapter, because they also monitor internal voltages. (See More show Commands.)

Normal Startup Sequence

LEDs indicate all system states in the startup sequence. (See Front Panel LEDs, and Rear Panel Connectors and LEDs.) 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, and then proceed to the appropriate sections to try to resolve the problem.

The power LED (POWER) comes on immediately and is green, to indicate that the unit is receiving power. This LED comes on during a successful boot and remains on during normal operation of the Cisco uMG9820.

If this LED remains off when you start the Cisco uMG9820, then either there is a problem with the power supply (it is damaged or not connected correctly), or the processor card is not connected properly. Proceed to the discussion of the power subsystem in Subsystem Troubleshooting Tips.

The power supply and fan LED (PS/FAN) comes on and transitions from yellow to green, to indicate that no error condition has been detected on the power supplies or the fan assembly. This LED comes on during a successful boot and remains on during normal operation of the Cisco uMG9820. These LEDs flash if a redundant power supply is not installed.

If this LED remains off when you start the Cisco uMG9820, or if this LED fails to turn green, proceed to the discussion of the fan assembly subsystem in Subsystem Troubleshooting Tips.

The processor card LED (PROC) comes on initially at power up and is yellow during bootup. The LED turns green after a successful boot.

If this LED fails to come on or turn green, proceed to the discussion of the processor subsystem in Subsystem Troubleshooting Tips.

Each QAM card LED (QAM) corresponding to a slot for which there is a QAM card installed comes on and then transitions from yellow to green, to indicate that no error condition has been detected on the corresponding QAM card. Each LED corresponding to a slot for which there is no QAM card installed does not come on.

If a QAM card LED for a slot in which there is a QAM card installed fails come on or to turn green, proceed to the discussion of the QAM/RF subsystem in Subsystem Troubleshooting Tips.

Subsystem Troubleshooting Tips

Troubleshooting Major Subsystems

Table 5-1 presents tips for troubleshooting the power, processor, QAM/RF module, and fan assembly subsystems.

Table 5-1 Subsystem Troubleshooting Tips
Subsystem	Symptom	Action	Comments
Power	Power LED (POWER) is on.	No action is required.	Power source is good, power supplies are functional.
	POWER LED is off.	1. Make sure that the power cable is connected at both ends.	If cable is properly connected, suspect power source or cable. Proceed as follows.
		2. Connect to another power source, if one is available.	If new power source is used and POWER LED comes on, first source is faulty. If POWER LED still fails to come on, proceed to Step 3 for this subsystem.
		3. Replace the power cord.	If the POWER LED comes on, the first cable is faulty. Return the faulty power cord to Cisco for replacement. If the POWER LED still fails to come on, proceed to Step 4 for this subsystem.
		4. Check the fuse and replace it as needed.	The fuse has blown, is defective, or is not seated properly.
		5. Disconnect power to the unit, and contact a Cisco service representative for further instructions.	One or both power supply modules may be faulty.
Processor	Processor LED (PROC CARD) is on and green.	No action is required.	Cisco uMG9820 has initialized successfully; system is operational.
	PROC CARD LED is on and steady yellow.	1. Confirm the internal status of the processor card by using a variety of CLI commands.	Steady yellow indicates a hardware failure. Proceed to Step 2 for this subsystem. See More show Commands.
	PROC CARD LED is on and flashing yellow.	2. Reinsert the processor card and restart the system.	Flashing yellow indicates that the fan assembly microcontroller has not detected the heartbeat from the processor in the last 5 seconds. If this fails to clear the problem, proceed to Step 3 for this subsystem.
		3. Disconnect power to the unit, and contact a Cisco service representative for further instructions.
QAM/RF	QAM LED (QAM) is on and green.	No action is required.	Cisco uMG9820 has initialized successfully; system is operational.
	QAM LED is off.	1. Refer to procedures for power and fan assembly subsystems in this table.	If the power supply and fans appear operational and the QAM LED is off, the QAM card may be connected improperly. Proceed to Step 2 for this subsystem.
	QAM LED is off.	2. Reinsert the QAM card and restart the system.	If this fails, proceed to Step 5 for this subsystem.
	QAM LED is on and yellow.	3. Confirm that there are at least two QAM cards in the system.	A minimum of two QAM cards is required. If there are at least two cards, proceed to Step 4 and Step 5 for this subsystem.
	QAM LED is on and yellow.	4. Confirm each QAM card's internal status by using a variety of CLI commands.	See More show Commands.
		5. Disconnect power to the unit, and contact a Cisco service representative for further instructions.	If a QAM LED is either off or remains on and yellow, the system has detected a hardware failure in that specific card.
Fan assembly	Airflow is noticeable; fans are moving. Power supply/fan assembly LED (PS/FAN) is on and green.	No action is required.	Fans are operating correctly, and the system has detected no faults. Tip Feel for airflow with your hand. If necessary, remove the bezel to observe fans.
	Fans are not moving.	1. Refer to procedures for the power subsystem in this table.	There is a problem with the fan or power.
	Power supply/fan assembly LED (PS/FAN) is on and yellow.	2. Reseat both power supplies and the fan assembly.	The system has detected a fault with one or both of the power supplies or the fan assembly. If this fails, proceed to Step 4 for this subsystem.
	Power supply/fan assembly LED (PS/FAN) is on and flashing.	3. Install a redundant power supply.	If only one power supply is installed, green and yellow LEDs flash.
		4. Disconnect power to the unit, and contact a Cisco service representative for further instructions.	Caution At any indication of a fan failure, even at ambient temperatures, replace the fan assembly. This is to protect the QAM modules from being damaged.

Troubleshooting GE Ports

The following may be useful in helping to identify sources of error related to GE transport.

Polling Resources in Support of Failover

The microcontroller on the processor card detects whether an small form-factor pluggable (SFP) module is present in the GE ports. If an SFP module is present in a port, the processor card can then poll the SFP module to detect whether a fiber-optic cable has also been connected to that SFP module.

If the active GE port goes down, then the processor card checks the inactive port to see whether it has an SFP module and fiber-optic cable is attached. If so, the processor card activates that port and deactivates the port that went down.

As expected, if the inactive port is identified as not being ready to carry traffic (that is, both an SFP module and fiber-optic cable are not detected), then no failover switching takes place.

GE Port ALM LED Functionality

The MAC chip on the processor card detects PHY, CD, TX packet, and RX packet errors, as defined in the IEEE 802.3z standard. (The user cannot set the definitions and thresholds for these errors, as they are dictated by the standard.)

The MAC chip maintains a counter for the occurrence of each error type, and the microcontroller polls the MAC chip once per second. If any one of the counters is incremented, the ALM LED comes on.

If there is no change to any of the counters from the last time the counters were polled, then the ALM LED goes off. If any of the counters is incremented since the last time the counters were polled, the ALM LED remains on.

GE Port ERR LED Functionality

The microcontroller on the processor card maintains a bistate error flag for the TX and RX buffers. The occurrence of a TX buffer underrun or RX buffer overflow changes the state of the respective error flag to the "error" state. If the TX buffer or RS buffer returns to the expected operation, then the state of the respective flag is switched back to the no error state.

The microcontroller polls the TX buffer underrun and RX buffer overflow flags once per second (the same interval at which it polls the MAC chips). If the state of one or both error flags is in the error state, the ERR LED comes on.

If both error flags return to the no error state, the next time the flags are polled the ERR LED goes off. If either error flag is still in the error state the next time the flags are polled, then the ERR LED remains on.

Using CLI show Commands to Troubleshoot

The additional show commands are useful for environmental troubleshooting, as well as for retrieving software version and logging information,

Troubleshooting Ethernet Port and QAM Channels

In addition, "Product Overview," presents a variety of CLI show commands that are useful in troubleshooting GE and FE ports, as well as QAM channels.

Table 5-2 CLI Troubleshooting Commands
Category	Reference	Comments
GE Port and Video Session Commands	Retrieving Packet and Buffer Statistics	Displays packet and buffer statistics for the specified GE port.
	Retrieving IP Status	Displays the IP status of the specified GE port.
	Retrieving Input Session Data	Displays video session information, input errors, session state, jitter buffer status, and continuity count errors.
	Retrieving Input Session PSI Data	Displays video session program number, elementary stream ID, and PID.
FE Port Commands	Retrieving FE Port Statistics	Displays link status (up/down) and packet and buffer counters.
QAM Commands	Retrieving QAM Statistics	Displays QAM statistics for a specified QAM channel.
	Retrieving QAM Output Video Data	Displays video program data for a specified QAM channel.
	Retrieving Video Session Information	Displays video session information for all active sessions, for all sessions (active and inactive), or a specified UDP session.

More show Commands

A variety of additional show commands support the following tasks useful in troubleshooting:

Retrieving Environmental Status

Use the following environmental commands to see power, temperature, voltages, and fan (RPM) data, either singly or collectively:

show env alarms

Under normal conditions, this command shows nothing. If there is one or more alarm state, this command shows one or more of the following:

Note

The following is only a complete list of all possible alarms, not an indication of what is seen for a given alarm state.

show env all

show env fan

show env power

show env temperature

Retrieving QAM Card and Cisco uMG9820 Software Versions

The following commands retrieve the software versions, respectively, of the QAM card and of the Cisco uMG9820 unit itself:

Note

Error messages reflect the absence of specific resources, which vary from configuration to configuration.

show version

show umg9820

Retrieving ARP Table Information

The following command displays the complete Address Resolution Protocol (ARP) table with IP address, MAC address, resolution type, and interface information.

show arp

Retrieving Entries in the Local Log File

The following command displays the entries in the current log file. The number-of-lines parameter determines the number of most recent log entries to be displayed.

Table Of Contents

Troubleshooting

Overview

Before You Call for Technical Assistance

Creating an Information Dump

Solving Startup Problems by Using a Subsystems Approach

Normal Startup Sequence

Subsystem Troubleshooting Tips

Troubleshooting Major Subsystems

Troubleshooting GE Ports

Polling Resources in Support of Failover

GE Port ALM LED Functionality

GE Port ERR LED Functionality

Using CLI show Commands to Troubleshoot

Troubleshooting Ethernet Port and QAM Channels

More show Commands

Retrieving Environmental Status

show env alarms

show env all

show env fan

show env power

show env temperature

Retrieving QAM Card and Cisco uMG9820 Software Versions

show version

show umg9820

Retrieving ARP Table Information

show arp

Retrieving Entries in the Local Log File

show logging number-of-lines