Cisco uBR924 Installation Manual page 63

Chapter 4 Troubleshooting
Table 4-1 summarizes the self-test failure codes displayed by the LEDs; these patterns appear only
when the OK LED turns OFF and remains OFF during boot.
Table 4-1
DS
ON
ON
ON
ON
ON
If the main initialization routine successfully completes, all LEDs turn off.
3. If all self-tests passed, the router boots the Cisco IOS image stored in its NVRAM memory. The
OK (power) LED blinks during the boot process and remains on if the router was able to
successfully load and start up the image. If the LED does not start to blink, proceed to the "Power
Subsystem" troubleshooting section.
The router starts normal operations after it starts up the Cisco IOS image. At this point, the US,
4.
DSNR and LINK LEDs remain on to indicate the router is operational and receiving a healthy
signal:
–
–
–
–
–
–
–
Note
When the router and computer have booted successfully, you should be able to access an Internet
5.
web site, which will confirm that the router is configured correctly. If you cannot access a web site,
proceed to the "PC Subsystem" section on page 4-9.
OL-0338-01 (3/2000)
LED Self-Test Failure Codes
US DSNR V OK
ON
ON
ON ON
ON
The DS LED indicates the router is locked to a downstream channel.
The US LED indicates the router has established connectivity with the CMTS and is operating
within 6 dB of desired power level (generally within 3 dB).
The LINK LED indicates the cable interface is operational.
The DSNR LED reveals the router is receiving a quality downstream signal with a low
signal-to-noise ratio (SNR) and that is 5 dB above the downstream lock threshold.
The ACT LED blinks to indicate activity on the cable interface.
The Ethernet 1, 2, 3, 4 LEDs blink to indicate activity from the PCs and other customer
premises devices connected to the corresponding Ethernet ports.
The V OK LED indicates the VoIP system is operational. The V1 and V2 LEDs light when the
voice ports are active. (These LEDs light only if the router has loaded a Cisco IOS image with
voice support).
Because the signal-to-noise ratio and lock threshold can drift, they are regularly
checked and the DSNR LED is updated. While this might cause the DSNR LED
to occasionally blink briefly, under normal conditions the DSNR LED should
remain on.
V1 V2 Error Description
Initialization of the memory controller failed.
ON The self-test of the low registers of the DRAM
failed. This indicates a processor cache failure.
ON A memory or controller problem was detected
during the DRAM initialization.
ON A memory or controller problem was detected
while clearing the BSS area of the DRAM.
A memory or controller problem was detected
while clearing the remaining DRAM.
Cisco uBR924 Router Hardware Installation Guide
Initialization and Self-Test Problems
4-3