Unplug the modem’s power cord from the outlet
Wait 30 seconds
Plug the power cord back in
Wait for the modem lights to stabilize
If needed, press and hold the reset button on the modem for 10 to 15 seconds
Release the reset button
Wait for the modem to restart and reconnect
If the modem still does not work, restart your router as well
If the issue continues, contact Comcast support