C6300 Lost internet signal

I have a C6300 AC1750 WiFi modem/router. I use Time Warner Cable as my internet provider. Yesterday, after being on the internet successfully, the Internet connection dropped. My devices show a wifi connection but cannot connect to the internet. I tried turning all devices off and powered down the modem/router several times followed by a re-start and still no internet. The internet light indicator on the modem/router does not light up at all anymore. I called TWC to see if there was a service interruption in my area and they claim everything is normal. I get TV reception on all of my coax cable connections so I tried another working coax cable into the modem router. Still no internet but it seems the Wifi is transmitting ok. I tried the reset button on the back panel and that didn't work either. Time Warner Cable is coming over on 8/18/16 for a support visit but since I own this modem/router, if they determine their signal is good, they probably won't support any issues with the modem/router. This unit is less than 2 years old and it wasn't cheap. I'm hoping that there's something that I missed that can solve the issue. I don't want to buy a new unit. Any help would be greatly appreciated.
Thank you!