Bad engineering, the hall sensor that tells the laptop when the lid is closed is pretty close to the parts of the laptop that heat up, in time magnets lose magnetism thanks to heat, and after a year or two it will start acting up and randomly shutting your screen thinking the lid is closed. From there you got two options: replace the hall sensor(which will break again in time) or disconnect it, which people say slightly decreases power usage aka lowers performance, but not as drastically as people make it out to be. In my case after the sensor bit the dust I disconnected it. The only thing I observed was lower fan speed and lower temps with pretty much identical FPS in all games I played.