I never got either of my devices to work so ended up purchasing Fire Sticks to replace them. I can't believe there STILL isn't a solution to this issue
Just to update: ROKU support tried to help me but after days of offering up obvious troubleshooting steps it's clear they have no clue how their devices are randomly bricking. I threw mine in the garbage today and ordered the Amazon fire stick as well, I suggest everyone do the same. I will also likely return my new TCL 65" Roku TV as well from this experience. Keep all my stuff with Amazon. Thanks for trying at least ROKU support.
This is exactly it in my case. Roku 3, turned on the TV to find that it was stuck on the load screen. It turns out that the microSD card got corrupted and could not load. Removing it fixed the problem. I used a spare from another device and reformatted it. I'd advise everyone with this issue to check if you have a memory card. That could be the issue.