I dont understand why you cant connect with the new wifi.......
I dont know if the following will help with your tv but;
Settings/Remotes and Devices/pair new device/remote>>
[post moved to appropriate board]
Thanks for the inquiry.
If you need a replacement remote for a Roku TV, you would need to contact your TV manufacturer. You can contact Hitachi here: http://www.hitachi.us/contact_support/personal
You can also purchase a remote that is compatible with your Roku TV here: https://www.roku.com/products/accessories/roku-tv