Unlock Panasonic KX-TSC35SUW Digital Telephone System

Not sure if this would help, but won't hurt to try..

1.
Connect to the Web UI
a.
Connect the Phone and a PC to the network
b.
Check the IP address of the phone using a handset.
[Menu]->[IP Service]->[Network
Setting]->[IP Settings]
c.
Enable the phone's Web UI using a handset
[Menu]->[IP Service]->[Network Setti
ng]->[Embedded Web]->[On]->[Save]
d.
Enter the IP address in a PC's Web Browser.
example: Enter "http://192.168.1.68"
in the address bar of Internet
Explorer
e.
Enter Authentication ID and password
ID:customerserviceid
Password:cspass
f.
Now you can upload new Firmware
into the phone using Web browser.
Note: The phone's http server port will automatically close after idle time of 30
minutes.
2.
Factory Reset
a.
Move to Maintenance - Re
set to Defaults screen.
b.
Click [ Reset to Factory Defaults ]
c.
Please wait.
The Base unit will reboot automatically

If you need further help, I’m available over the phone at https://www.6ya.com/expert/william_02fc2766c1e13b73