If you read my posts of the numerous issues I've had, my replacement motherboard went bad and had the exact same thing happen. I guess it's at least a bad batch of motherboards. Mine shut down during Netflix, never to turn on again. Had to send it in, they replaced the motherboard again.
You are going to have to send it in for service.
Asus G20CB - Core i7 6700, Nvidia GTX980, 16GB Ram, 256GB SK Hynix SSD, 1TB Samsung SSD.