The screen on my tv is black but if I put a flashlight close to the screen I can see a little. I tried unplugging the tv and waiting but nothing changed. Resetting it didn't change anything either... Please if someone has a solution that would work it would be very kind.
Roku only supplies the operating system for a "Roku TV". This sounds like a hardware issue (likely loss of backlight on the screen) that needs to be referred to the manufacturer of the set.
Roku TV Manufacturer Support Contacts:
https://community.roku.com/t5/Manufacturer-Support-Warranty-Resources/Contacting-Support-for-Your-Ro...