Owned 3 in the past. My G74Sx decided to give up the ghost. It looks to be somekind of power problem. I was playing Civ V and it turned off. Completely. No lights or anything. Only way to get it back was to pull AC power, Pull battery, reseat battery, and reseat AC. Then it worked again.
Went back into windows, seemed fine, Power brick was hot as ever (always this way when gaming), so I put a fan next to it, also decided to turn on GPU-Z temp log and went back into Civ V. Soon after it again turned off completely. Started looking at what it could be. Checked the log, GPU got to 64C before the power off. Not very hot. Looked at other things.

I then ran MEMTEST86 just to check. It failed about 5 mins into it. shut off. I thought ok memory. Pulled out my two stock 4GB sticks. It failed again about 4 mins into it. ok, my Vengance is bad. Pulled those out, replaced with stock, powered up, failed again about 2 mins in. Pulled them out, put them in the other two different slots, failed again even faster... So All memory tested in all configurations and all failed.

I then saw the flickering battery light. Very faint flicker. I reseated power/battery and the battery light came on. I decided to go to lunch and leave it on. I came back, and the battery light was solid (charging) then soon after it started flickering. Whenever it flickers, I have to reseat both the battery/AC power to get it back. Now it stopped booting all together. I press power, I get the flickering battery light, and nothing.

I'll also say I have a friend who also owns a G74, we bought them about a month apart. I tried both his AC power and his battery, and I get the same thing, so thats what makes me believe its the power module in the laptop.

I will say the whole time I have owned this laptop, I have been VERY easy on it (targas leather briefcase like setup with a lot of padding), it looks brand new with zero scratches. Taking extra special care of the power connector after reading of all the horror stories regarding its problems.

So I now get to send it in for repair. 😕 already contacted Asus support and have an RMA. I'll report back once I get it back. Hopefully it comes back in good working order. Pulled my memory, battery, HDD's, per rep.