restart/shut down

Firstly, thanks to my community contributors. My system started having issue last Saturday. I have tried everything and it seems things are getting better. Lastly, what I did was that I reinstalled the OS and later, installed Onyx, though for now, I can't verify that the problem is gone...

My laptop is about 3 weeks old. Tonight I was watching an instructional video on YouTube when suddenly the sound disappeared. I've been unable to retrieve it. In addition, when I tried to restart or shut down the machine, nothing happened. I had to shut it down by pressing the power button...