Asus n750jk sound issue[help please]

Hello people,

I think I might have an issue with the sound of my asus n750jk asus. I bought the laptop mid August just before I went on holliday so I didn't really needed the laptop so I let it at home and when I came back I wanted to use my laptop to studdy for a few exams I noticed it made a lot of noise but at the time I just thought is was the fans or my hardrive making the noise until after my exams I start using it for other things like games and stuff.

Then I noticed the sound was pretty bad it had some kind of static sound to it and the boxes kept making a wierd sound that could be confused with fans blowing hard or hdd making noise, I can't quite describe the noise but then I went to the shop where I bought it they noticed the noise too so they sent it back. After something more as a month I got my laptop back from Asus but some times the laptop makes a weird sound with the littlest of sound that passes through the speakers and some times I need to start the elder scrolls skyrim 2 to 3 times to let my laptop make that noise.

The noise stops when I go the device manager and go to the sound, video and game controllers and turn out the sound the noise goes away but not if I turn of the noise at the audio in and outputs menu at the device manager. I really hope someone can help me I paid a lot for that laptop .

It runs on windows 8.1 ad I have updated the sound driver multiple times full name laptop n750jk-T4030H-BE.

Thank you in advance.