Wi-Fi, cable, as hotspot not working?

I unplugged the cable box and modem to switch it to a different TV, it worked when I switched it but when I plugged it back into where it originally was, nothing works. I have Xfinity Comcast and it says it can't connect to the X1 Platform. I've tried rebooting the system. The Wi-Fi also isn't working, the Wi-Fi light is lit up sometimes flashing but the online light isn't lit up. I've tried resetting the modem several times. I even tried to turn the hotspot on my iphone and watch netflix on the ps3 but every time I try to sign into PSN it says I can't because there's a DNS server connection issue. Can anyone help me out?

You can just free download My Wi-Fi Router software, it's totally free to use and will turn your laptops into Wi-Fi htotspots just with a click. Also you can create two and even more hotspots to make Wi-Fi perform better. Free download address, http://www.mywifirouter.me/download/

Call Comcast support.