Individual keys on keyboard problem

Hi,

I have problem with keyboard on laptop. Keys "x" "s" "ESC" "z(key on the left side of x)" are not working. It's new keyboard and it worked maybe for 2 or 3 days than this problem happened. I changed keyboard (whole upper panel with keyboard) because old keyboard had same problem but with other keys. I don't know where is the problem.

Thanks for answers.

Now I tested it and other keys stopped working. What should be problem?