Cisco 7985G Administration Guide - Page 125

Chapter 9 Troubleshooting and Maintenance General Troubleshooting Tips Table 9-1 Cisco Unified IP VIdeo Phone Troubleshooting (continued) Summary Moving a network connection from the phone to a workstation Explanation If you are powering your 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. Caution The computer network card cannot receive power through the network connection; if power comes through the connection, it can destroy the network card. 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 a phone is no longer on the line and to stop providing power to the cable. Changing the telephone configuration Phone resetting LCD display issues Dual-Tone Multifrequency (DTMF) delay By default, the system locks the network configuration options 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 "Unlocking and Locking Options" section on page 4-3 for details. The phone resets when it loses contact with the Cisco Unified CallManager software. Any network connectivity disruption including cable breaks, switch outages, and switch reboots can cause this lost connection. If the display appears to have rolling lines or a wavy pattern, it may 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, the system may not recognize some of them. OL-8726-02 Cisco Unified IP Video Phone 7985G Administration Guide 9-12