Old ROKU and brand new ROKU won't connect to internet. Red light was flashing, and then it became white and continued flashing.
What are the model numbers of the two devices displayed under Settings->System->About? What happens when you try to connect? Any error messages or codes?
If they're 2.4GHz-only models or you only have 2.4GHz Wi-Fi available ensure your router's wireless mode is set to b/g/n and not g/n.