Hi,i wanna use cisco ip phone 7940 as sip ip phone.when i power up the phone ,it can get ip from network,but finally,it shows "TFTP timeout"in display led.All the buttons can not be used.What does it mean by"TFTP timeout" What should i do to make it work well.Thank you.

You should be able to find a link to what you need on this page -> http://www.cisco.com/en/US/products/hw/phones/ps379/tsd_products_support_series_home.html

Hi

This happens when you IP phone communicated with the Voice vlan with the IP address of data vlan.

To solve it manually enter the IP address of the TFTP server and option 150 on the DHCP server.
remove the voice vlan from the switch port and reboot the phone
again add the voice vlan and reload the phones

Here's a great little document from Cisco directly, called "Converting a Cisco 7940/7960 CallManager Phone to a SIP Phone and the Reverse Process"
Easy to do, just follow the step-by-step directions.
http://www.cisco.com/en/US/products/hw/phones/ps379/products_tech_note09186a0080094584.shtml

Yes, there is programming which would need to be removed. However, you would need a cisco call manager($800) at home. Unless of course you have voip in your home. then you could just set it to DHCP I'm assuming and then it should just work!

Here are the instructions for configuring these units for 3cx

http://www.3cx.com/sip-phones/cisco-7940.html

http://www.3cx.com/sip-phones/polycom-soundpoint.html

Since the 3cx softphone worked well, I don't see why you couldn't configure each as for 3cx and make them work as well.

how can i fix the sound of my magic

you need different files to upload by tftp
by example version 8
P0S3-08-2-00.sb2
P0S3-08-2-00.sbn
P0S3-08-2-00.bin
P0S3-08-2-00.loads
OS79XX.TXT (tells the version)
SIPDefault.cnf

Unlocking a Cisco 7940

Method 1:
1) Unplug the phone
2) Plug the phone back in while holding the # key
The phone will soon display “Reset key sequence detected”
3) After several lights flash press the following keys in order:
1 2 3 4 5 6 7 8 9 * 0 #
4) The phone will then ask you if you want to save the network configurations:
Save network cfg? 1=yes 2=no
5) The phone will soon display “Factory reset initiated” and will continue
through the boot up process.
If that process fails to work for some reason there
is a second method.

Method 2

Complete these steps:

1. Press Settings.
2. The Network Configuration lock symbol must be unlocked. If not, exit to the main window and press ** # again.
3. Press 3 on the keypad (or scroll down) for Network Configuration.
4. Press 33 on the keypad (or scroll down) to Erase Configuration.
5. Press the Yes softkey.
6. Press the Save softkey.

The phone will now be reset.

Also see this link
http://www.cisco.com/univercd/cc/td/...tain.htm#93250

Try to manually reset the phone - **#"Settings" (this will unlock the configuration) + Network + menu under number "33" - erase the configuration. Then the phone configuration will be erased. Also you can manually set IP address and TFTP server

Did you check the TFTP settings on the IP phone? You may need to disable DHCP on the phone and assign the TFTP manualy or make sure the correct TFTP server is assigned.