[ubuntu] My keyboard doesn't work sometimes

Hi guys!! How are you?

Im very good, but some time ago I have a problem with the keyboard of my laptop (Samsung np350v4c-s07cl): sometimes this does not work. Just the keyboard, all other devices and programs don't stop working. I can continue listen music, and using my laptom with the touchpad or mouse, but not write.

This occurs ramdomly but is more frecuent when exist open more than three or four applications. The problem can last a few seconds or several minutes. I can't know why this occur and how its function retu; however, I noted that if I try to write in diffrent sites (bar of the web browser, note pad, etc), the keyboard retu its function faster than if I just wait. If I suspend, usually the problem dissapear too, but is very frustating can't work continuosly.

My version of ubuntu is 16.04, but when I had Ubuntu 14.04 and Ubuntu Mate 14.04 I also had the same problem. In windows this not happens.

Thank a lot for your help!!
Greetings!

PS: sorry for my english, is not my native language.