Gateway/access point not found or connection error

See subject. I have followed all the instructions I can find from the att troubleshooting. I am hooked up to two tvs wirelessly and neither is working. They both keep giving the same message. I have unplugged and replugged everything countless times. I have pressed the buttons I was told to press. All for naught. My brother did set up an eerie mesh. Is that the problem? I cannot get any lights on the waps.