Cisco WS-C2950-12 Hardware Installation Manual page 98

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.
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.
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-7.
• 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.
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 switch software
configuration guide.
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