I am in the same boat. I had dl a bunch of apks and accidentally hit the launcher manager and some how selected it in the wrong order I guess. I thought I was exiting it! It boots up I see the onn logo google tv logo then goes to black screen and says diagnostic mode completed. I can’t get out of black screen to disable launcher manager. Voice does not work says it’s not connected to the internet. No visible hold to force a factory reset. Noob here!