I have a Roku Premiere 3920X that has recently stopped being able to locate WiFi networks. I have read through the forums trying to find a solution, but haven't found anything that has solved the issue.
Here are the steps I have taken:
1. Unplugged the Roku.
2. Unplugged the router.
3. Moved the Roku directly next to the router.
4. Factory reset.
5. Verified the 2.4GHz band is active. B/G/N mode is activated.
6. Tried mobile hotspot from my laptop. My phone picked up the network along with several networks from neighboring houses. Still no networks are showing on the Roku Premiere.
If no networks show up your 3920, like mine and many others, is probably toast. As a last ditch effort try a factory reset - find the pinhole reset button and using a paperclip or something similar press and hold the button for no less than 30 seconds with the power connected. If that doesn't work and it's less than a year old research a warranty replacement. If it's older than that, smash it with a hammer.
Roku Community Streaming Expert
Help others find this answer and click "Accept as Solution." If you appreciate my answer, maybe give me a Kudo.