I recently ran into an issue where random devices wouldn’t connect to my WiFi while others could. None of my android devices could connect including my phone and tablet but most Windows 7 devices could. A friend brought her Windows 7laptop over and was unable to connect it to my WiFi.
I just spent two weeks troubleshooting the issue which should have been more obvious. At first I thought it was because I had setup the encryption as WPA2 and the devices didn’t
It was definitely a stupid mistake on my part but one that is easily overlooked.
Check your WiFi settings and verify the mode. It turns out I had set the router to Wireless N only and the devices that couldn’t connect only supported up to Wireless G. I switched the router to Wireless G/N and all the devices started working.
On Verizon’s router, go to Wireless Settings -> Advanced Security Settings
Under Level 3, you’ll see “802.11b/g/n Mode”.