The tv lost picture randomly. Turned off and unplugged for 30 minutes. Picture is back, but with an annoying black shadow across the top and right corner. Have tried everything I can find to try online, including factory reset.
I take it you’re using a Roku TV. Roku’s does not make TVs by the way. TCL,ONN, Hisense and Sharp do. Who manufactured your TV? When did you purchase it?. If your TV is more than a year old it’s out of warranty and there’s not much you can do about your issue except replace the TV
A number of TV manufacturers license Roku technology for inclusion in some set models and market them as "Roku TVs". Roku doesn't manufacture "Roku TV" sets, it only supplies the Roku operating system.
This sounds to me like a hardware 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...