All the official solutions tell one to check settings, etc. Can't do this if the screen and remote are frozen. I have followed all the suggestions given from turning off to pulling the power to reinserting the batteries. I do not have more time to play with this, already four days. My solution is to send it back to San Jose and see if someone there can figure it out and give me instruction.
You could try using the Roku app as a remote on a phone of tablet.