Roku doesn't manufacture TV sets sold as "Roku TV", it only supplies the Roku operating system. This sounds like a hardware and possibly warranty issue that needs to be referred to the manufacturer of the set.
Manufacturer support contacts for Roku TVs can be found in this support post: https://community.roku.com/t5/Manufacturer-Support-Warranty-Resources/Contacting-Support-for-Your-Ro...
Roku Community Streaming Expert
I am not a Roku employee, only a user like you. Please, no support questions via private message -- post them publicly to the Community where others may benefit as well.
If this post solves your problem please help others find this answer by clicking "Accept as Solution.".
Streaming Stick 4K+ 3821 | Streaming Stick+ 3810 | TCL Roku TV 43S245/C107X