@akmaldurrani-
If a Factory reset doesn't fix it, this sounds like a backlight failure 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.".
Ultra 4800 | Streaming Stick 4K+ 3821 | TCL Roku TV 43S245/C107X
