Troubleshooting cisco700 series routers, Power-on self-test, Led diagnostics – Cisco 700 User Manual
Page 63: Chapter 5, Troubleshooting cisco 700 series routers

C H A P T E R
Troubleshooting Cisco 700 Series Routers 5-1
5
Troubleshooting Cisco 700
Series Routers
This chapter helps you find solutions to problems you might be having with your router.
Begin by attempting to isolate the problem to a specific source.
Power-On Self-Test
When the router is powered on, it performs a series of self-tests. After these tests are
completed, the LEDs indicate operating status. Any operational problem is represented by
a combination of lit and unlit LEDs. Cisco 760 series routers have 12 to 14 (depending on
the model) LEDs on the front panel. Cisco 770 series routers have 15 to 18 LEDs on the
front panel.
Note
The function of each LED is described in the “Front-Panel LEDs” section of
LED Diagnostics
The front-panel LEDs can be used for diagnostic purposes. Table 5-1 lists the combinations
of lit and unlit LEDs and their significance.
To verify your Ethernet connection, check that one of the following LEDs is on:
Table 5-1
LED Error Messages
RDY
NT1
LINE
CH1
CH2
Test Result
On
Blinks several
times a
second
Off
Off
Off
Internal NT1 is unable to synchronize with the
ISDN switch.