MrMann, you might want to ask onn if they have any ideas. They may just point you right back to Roku, but it's worth a shot. Maybe they have another way to do a USB update.
Where can I get support for my Roku TV� | Official Roku Support
It's been a while since I did the USB update thing and I do remember having a little bit of a problem with it, but I can't remember exactly what it was. The following procedure is for when your TV hasn't been set up and linked to a Roku account yet. You could get back to that state with a factory reset, but if you did that the update may not even require the USB method. I usually only recommend a factory reset as a last resort.
How to use USB to update your unconnected Roku TV⢠| Official Roku Support