I bought my Asus X750JN laptop new in 2014, and it never worked right from Day 1, but I thought I could live with it. 17.3", core i7-4700HQ quad + nVidia 840M. Constant power on and wake from sleep issues. Won't power on, about 75% of the time. The worst thing is, it has an internal battery, and it's a royal pain to take this $900 POS apart - very tedious, involved process. It literally was getting to the point that every time I had to turn the thing on (or wake it), I'd have to take it completely apart down to the motherboard, to remove and re-install the battery, along with re-seating (or swapping) the RAM sticks in their slots, and removing/re-seating the CMOS battery, just to get the damn thing to turn on. I've almost thrown the whole thing in the trash, several times.
Almost no support from Asus, even when it was in warranty. When I'd call for support, I always got the same rude run-around / blow-off. And when I'd post to Asus support forums (or to review the product, like on Amazon), Asus' little minions would cut/paste the same boilerplate response: "We're sorry you had such a bad experience...did you try unplugging it and removing the battery (can't remove it, unless you take the damn thing apart, which I mentioned over and over again)...." "...hold down the power button for 30 seconds.... (blah, blah, blah)..." Every customer gets the same pointless, useless treatment.
I have concluded that Asus does not know how to design a battery charging / power circuit to save their life. Even with this horrendous design defect across multiple product lines, they let 'em ship out the door. Unbelievable.
My final solution was to leave the battery out completely and run the POS on an APC UPS (600VA) ...which is fine, because I've now consigned this miserable Asus POS to running the World Community Grid client 24/7/365...which it now does just fine, no thanks to Asus. I've adjusted the Power Plan in Windows 10 so the CPU is always around 47°C - 53°, with rare spikes to 60°C.
I will never again buy any Asus products.