sorry, I too have the same issue with MSI GT70.
This morning I downloaded a game from Steam and about ten minutes into the game, my laptop completely shut off and now will not turn on. I have never dropped it or spilled anything on it and I had it set to go into sleep mode after 5 minutes without touching it. There is no sign of life when I try to turn it on. The power supply work fine with my external monitor so I know it isn't that. I've also tried every variation of unplugging the power cable and battery and holding down the power button but nothing has worked so far. I don't think the laptop has overheated because I have it sitting on a cooling pad and I rarely ever move the laptop. Any ideas on how I can fix this? It is under warranty but I'd rather not have to send it in and wait a month to get it back.