This Post describes how to reset your Cisco 7900 Phones. It applies to these models:
Cisco 7940, Cisco 7941, Cisco 7942, Cisco 7960, Cisco 7961, Cisco 7962 & Cisco 7920
Cisco IP phones are absolutely great ones. I have 18 in my network and they work very well. They have good quality and a great voice. Cisco phones work lifetime.
Like other IP Telephony networks, you may face some problems. VoIP telephone network gives you all you want, but they need maintenance. You should check your telephone network every day to make sure they work correctly.
One of the most common problems in VOIP Network is this: extensions un-register after some time.
The problem could be from your network connection. Sometimes network connectivity interrupts for a very short time and it may lead to un-registering the phones.
If you’re not sure, its better to factory reset your IP Phone first…
You should follow these steps in order to reset factory your cisco 7900 phone:
1- Unplug your phone to turn it off. Then plug it back.
2- Immediately, press and hold # button. After a few seconds, You will see this message on the screen: Reset key sequence detected. Now release the # button. Headset, Mute, and Speaker buttons start to flash sequentially.
3- Now press 123456789*0# buttons. A prompt will appear on the screen: Save network cfg? If you are using DHCP Server on your network, press no. If you pressed the wrong button by mistake, no worries. You can start from the beginning.
4- If you press the right sequence key, the following message will appear on the screen: Factory reset initialed.
And just wait and see the phone boot up. I hope it helps you.