Cisco 7902G Administration Manual page 140

General Troubleshooting Tips
Table 7-1 Cisco Unified IP Phone Troubleshooting (continued)
Summary
Moving a network connection from
the phone to a workstation
Changing the telephone
configuration
Phone resetting
LCD display issues
Dual-Tone Multi-Frequency (DTMF)
delay
Cisco Unified IP Phone Administration Guide for Cisco Unified CallManager 5.0 (SCCP), Cisco Unified IP Phones
7-12
Chapter 7
Explanation
If you are powering a phone through the network connection,
you must be careful if you decide to unplug the phone's network
connection and plug the cable into a desktop computer.
The computer's network card cannot receive power
Caution
through the network connection; if power comes
through the connection, the network card can be
destroyed. To protect a network card, wait 10
seconds or longer after unplugging the cable from
the phone before plugging it into a computer. This
delay gives the switch enough time to recognize that
there is no longer a phone on the line and to stop
providing power to the cable.
By default, the network configuration options are locked to
prevent users from making changes that could impact their
network connectivity. You must unlock the network
configuration options before you can configure them. See the
"Accessing Network Configuration Settings through the
Network Configuration Menu" section on page 4-5
The phone resets when it loses contact with the
Cisco Unified CallManager software. This lost connection can
be due to any network connectivity disruption, including cable
breaks, switch outages, and switch reboots.
If the display appears to have rolling lines or a wavy pattern, it
might be interacting with certain types of older fluorescent
lights in the building. Moving the phone away from the lights,
or replacing the lights, should resolve the problem.
When you are on a call that requires keypad input, if you press
the keys too quickly, some of them might not be recognized.
Troubleshooting the Cisco Unified IP Phone
for details.
OL-8151-01