r7450 not connecting to modem

i bought a nighthawk r7450 from walmart because my other wifi router from out internet service provider (spectrum) was fried by lightning this after noon ive done everything correct on setting it up but in the app it fails when checking cables ive tried 4-5 different cables and still nothing the internet light doesnt come on the wifi router and in the router settings internet is red and says not connected are there any solutions