Hello Nick, I don't have a solution for you right away. however from my experience, when you have something like that happening to an electronic device (starting or shuting down by itself), I think you have to look around for another device (may be a new device in the room or in the house) that can send waves to your TV. For instance, is this happening regularly (every 3 days at 10 PM for example) ? Is there any new electronic device in the room that could potentially affect the TV ? Also, I don't think the cause is something coming from the TV software because generally you receive a message (saying : are you still loooking at the TV ? ) and you didn't mention any message. I am sure that like me, you have a ton of electronic device around in the house, like routers, cameras, amplifier, computers, tablets, phones ...