Punch your keyboard, it works more often then you think.
Once I had a problem with my delete key, and some letters, like "u". Since theses letters were rarely used on gaming, I continued using my keyboard normally, but after some months, for some particular reason, I got really irritaded and punched my keyboard (it even broke those litle standings, I had to remount them) To my surprise, all keys were working normally after that.
Guys......... It's a laptop. No Punching it, no buying a new keyboard.
You need to remove the Spacebar key and check if the Buttons below it are pressed constantly or not.
What you can do is get a compressed air can and remove the keyboard after opening a few screws from underneath mostly just 2 of them will require to be unscrewed then the keypad(actually it's more like a pad then like a board) will just slide out with the help of a little nudge from the base towards the display.
If you are pretty tech savvy you can detach it completely inclusive of the ribbon cable connecting it to the chassis of the laptop and then clean it pretty well with a nice cloth and some compressed air. Also make sure the tin base is not bent or dented under the spacebar key.
It'll be fine after that I guess. Make sure to tighten the screws when you put it back in/on the laptop.
Or if it is still under the warrant period you could get it serviced pretty free for all you know they might just replace it with a new keyboard. Get in touch with the Asus People.
If everything can be bought by everyone around here, I don't see any point in troubleshooting on Tom's right? If he hadn't spent 2K on the Laptop, I'd surely tell him to buy a new keyboard, but he has spent a hell of a lot on his rig, wouldn't want him to put in anymore money if he could avoid it. So it's better he tries to get it to work first and then as a last option, buy another Keyboard for the Laptop which is not going to be cheap, as compared to a standard keyboard.
Punching and kicking rigs....hmmmmmmmmmmm reminds me of the Flintstones, only if we were all living in the very Hi-Tech Stone age.
And we're not here to "chat"... we're here to solve peoples problems regarding Tech.... quit trolling and help people or then just go and do the stuff you do on Facebook.