why not just send the adapter to asus for a replacement? you shouldn't need to pay for a new, possibly off-brand quality one. By the way I am
hoping it is actually the power adapter and not the power circuitry inside the laptop, otherwise that would mean a motherboard replacement at least.
ASUS G750JX -- i7-4700 - 16GB - 128GB 840 PRO SSD + 1TB HDD - Nvidia GTX 770M - 120Hz 3D glossy display