Restart the modem manually
Click through the screens below to see the steps. For upright tower modems – C3000, C3510, C424, C2100 and others.
Unplug the power cord from the back of the modem or from the wall outlet. The lights on the front will turn off.
Wait one minute to allow the memory to clear, then plug the power cord back in. The WiFi network will go offline while the modem restarts.
The modem will take a few minutes to boot back up. The POWER, INTERNET/WAN and WIFI status lights should turn green when it's reconnected. Once your WiFi network comes back online, check your devices again for a connection.