Roku Player Support.
Does support exist anywhere? I am trying to set upa brand new replacement device,
and going round in circles. Roku obtains internet connection,updates, and then goes blank. Repeat and reset makes no difference. Somewhere the suggestion is to contact customer support - but how?
https://support.roku.com/contactus
Note that if you have an Express device then you will just be directed right back here. Also, if your device gets its power from a USB cable make sure you're using the supplied adapter and not the TV's USB port.
Some have reported success in getting beyond the update step of new installations by connecting to a different network (a wifi hotspot on a cell phone or a friend's wifi). Once it has completed the update and starts to function, you can then change the network connection to your intended home network via Settings > Network > Set up connection.
This hasn't worked for everyone, but enough have reported success that it's probably worth a try.