Well, sorry to say this,buddy,but the gpu is DEAD. (99%)
The bios doesnt recognise a gpu is connected.

This is what happens to a g75vw when you dont have a GPU installed. (personal experience)
It shows the led's...then shuts down.
You need to see if it's a socket issue or the gpu just died.
Tho it's rare, gpu's DO die, especially if poorly handled....or the thermal paste goes bye-bye after 1 year~1.5 years of use.
This sometimes happens because the cooler surface isnt perfectly flattened on the cpu/gpu dye,and the paste just sits a little tilted to the side.This in time makes it go.
You can tell this happens when you clamp the heatsink on with NEW paste,and you see the smudge being left-sided, or right sided instead of being perfectly smudged in all directions.Tho it's a mass produced laptop, and it's somewhat understandable...

There is a SLIGHT chance that the bios went bye-bye.....buuuut i seeeriously doubt it.



Questions:
1. What did you do before this happened?What were the symptoms?What caused it? How old is the laptop?
2. Is the charge led turning on when you plug in the chord?When the power button is pressed, does it access the HDD ?
3.Take it to a laptop repair if out of warrantly, or,preferraly, an ASUS repair station.

Things to look for if you're in the middle of nowhere and you think you can open it up:
1.If the CPU dye is touched/slightly pressed down on the MBoard when you start the laptop, is the CPU warming up? The CPU socket may be faulty. Happened to mine as well after 2 yrs of perfect use.

2.Is the GPU dye warm when you start the pc? If yes, then the GPU MAY BE still functional....and you gotta look the problem omewhere else....

3.MB may need a closer check-up and a professional de-gunking, southbridge may need a look ,etc,etc....but i'm just stabbing in the dark here.


FINAL IDEA: GET it to a shop, it MAY or MAY NOT be the MB/ the GPU. You can't say for sure yet.
MB's can get fixed up to a point,so dont lose hope,mate.