I have the exact same problem after I opened the laptop (Asus UX303LA) so I could tighten the hinges on the display. I have looked after a new motherboard and they varry between 300 and 450 Euros. A bit expensive in my oppinion. I have updated the BIOS and of course it didn't help. The problem is obviously on the hardware side. It's a pitty since the battery was lasting around 6 hours.