Help & troubleshooting for network issues, including connecting your device to your home Wi-Fi network, connecting to public networks, troubleshooting wireless issues & ethernet connections, and optimizing streaming performance.
Re: ROKU WORKED FINE BEFORE, NOW NOT CONNECTING TO INTERNET,
The 3900 is a single band device, and doesn't support 5 GHz. If you can log into your router, see if it has a 2.4 GHz radio that is disabled, and if so turn it back on. Otherwise, yes you need a Roku with dual band support, such as the Stick, Ultra or one of the sound bars.
Dan Roku Stick (3600), Ultra (4640), Ultra (4670), Ultra (4800), Premiere (3920), Insignia 720p Roku TV, Sharp 4K Roku TV, Nvidia Shield, Windows 10 Pro x64 running Serviio and Plex on a wired Gigabit network.