last night i was watching tv i fell asleep when i woke back up my tv screen was flashing in an out I tried to turn tv off but it wouldn't let me so i unplug it to try to restart it but nothing happened
This would appear to be a hardware related issue. Have you tried contacting your Roku TV manufacturer support yet to inquire further? I'd suggest starting there to see what options or suggestions they can provide. Each Roku TV manufacturer provides direct support for their products running the Roku OS.