Cisco SPA504G Firmware update issue

SOURCE: Ethernet Disconnected message in POE 7941G IP Phones

the first problem will be to check or replace the cable that you use to connect the phone or check the jack that you use

SOURCE: IP 7920 & Asterisk

I believe I saw somewhere that the 7920 works best with the 4.02 version of firmware... only hitch is you can't get it unless you have a valid Cisco login with access to their voice stuff. You could see if your local partner could get it for you otherwise. Also, I think you need the cradle to upgrade the phone manually - otherwise you need a TFTP server set up and the proper keywords in the cnf.xml file. There is better info on voip-info.org about these sccp phones - god I wish they (Cisco) would release a SIP firmware for these things!

SOURCE: Converting Cisco 7940 IP Phone to SIP

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.

SOURCE: Cisco 7911G definitely dead?

You are very close to fixing your problem. You will need the correct firmware and files; these are proprietary but you should be able to acquire them from your certified reseller. Alternatively, here at IdacomUSA, we have the proper firmware on hand, and can flash the phone for you to get it back to life. Call us at 1-800-903-9190 or visit us at http://idacomusa.com