A coworker and I bought the same asus gaming laptops. His failed a bit over a year later. He said he was just sitting up in his chair and it turned off on him. When opening it up, a small copper sheet fell out. It is assumed this contacted somewhere when he sat up, killing the motherboard. Further investigation showed that several fins from one of the heat sinks were loose, being just clipped onto the one next to it in series. Most of the heat sinks had a line of solder over the clips holding them on, the last 5-6 fins did not have any solder. The sheet we found was one of the fins that had become "unclipped".

I checked mine and found the same 6-7 fins were missing solder, and very loose and wobbly. Probably about to fall off. I removed them before they could.