Chapter 3
Troubleshooting
Table 3-1
Symptom
No connectivity.
Unreadable characters on
the management console.
System LED is amber, and
all port LEDs are off.
System LED is amber.
OL-6156-01
Common Problems and Solutions (continued)
Possible Cause
Incorrect or bad cable.
No link at both ends.
A crossover cable was used
•
when a straight-through was
required, or the reverse.
The cable is wired incorrectly.
•
STP checking for possible
•
loops.
Switch not recognizing a GBIC
module.
Switch not recognizing an
SFP module.
Incorrect baud rate.
Corrupted software.
Internal fan fault detected.
•
Nonfatal or fatal POST error
•
detected.
Resolution
For the correct pinouts and
•
the proper application of
crossover vs.
straight-through cables, see
the
Specifications" section on
page
Replace it with a tested
•
good cable.
Wait 30 seconds for port
•
status LED to turn green.
Refer to your GBIC module
documentation for more
information.
Refer to your SFP module
documentation for more
information.
Reset the terminal-emulation
software to 9600 baud.
Attach a monitor to the serial
port to display the switch boot
loader. For more information,
see the switch software
configuration guide.
Check if the fan has failed
•
by using the show env fan
privileged EXEC command.
If the fan has failed, call
Cisco Systems.
Use the show post
•
privileged EXEC command
to see which POST test
failed.
Catalyst 2950 Switch Hardware Installation Guide
Diagnosing Problems
"Cable and Adapter
B-6.
3-3