A Roku tv IR remote does not have to be paired, it just works, it can only control a Roku tv and no other model of Roku. If the keys no longer work, it might be defective? Then you would need to get in touch with tv manufacturer, Roku only supplies UI for the Roku tv. They don't have replacement IR remotes that control ANY Roku tv. Only simple remotes Roku has access to are worthless on all Roku tv's, just works on stand-alone Roku devices. YTou could go to you local Walmart or Best Buy for Roku Wifi remote that can be paired with ALL Roku tv models. Or get a cheap universal remote that has Roku tv listed.
Edmund
Roku Community Streaming Expert
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