Cisco WS-C2950-24 Hardware Installation Manual page 88

Diagnosing Problems
Table 3-1 Common Problems and Solutions (continued)
Symptom
No connectivity.
Unreadable characters on
the management console.
System LED is amber, and
all port LEDs are off.
System LED is amber
Catalyst 2950 Desktop Switch Hardware Installation Guide
3-4
Possible Cause
Incorrect or bad cable.
No link at both ends.
A crossover cable was used
•
when a straight-through was
required, or vice-versa.
• The cable is wired incorrectly.
• STP checking for possible
loops.
Switch not recognizing a GBIC
module.
Incorrect baud rate.
Corrupted software.
Internal fan fault detected.
•
• Nonfatal or fatal POST error
detected.
Chapter 3 Troubleshooting
Resolution
For the correct pinouts and
•
the proper application of
crossover vs.
straight-through cables, see
the "Cable and Adapter
Specifications" section on
page B-6.
• Replace it with a tested
good cable.
• Wait 30 seconds for port
status LED to turn green.
Refer to your GBIC
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,
refer to the Catalyst 2950
Desktop 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.
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