CM1200 modem changed its name and lost connectivity

[sppd58]

I have a Netgear CM1200 modem and last night it changed it name back to default mode (NETGEAR83_EXT) from my assigned home name. I have logged into the modem website address and that did not allow me to fix it. I am lost. The password that worked for the named network does not work for the new reset network. The firmware is V3.02.01, Hardware version 1.01

I have no idea what to do next. Please help. Thanks in advance. 

[FURRYe38]

CM series modems don't have any built in wifi or router. 

NETGEAR83_EXT comes from a wifi extender. EX or EAX series. 

[plemans]

What'd you actually change the name of? There isn't anything to change in the modem