Reset button doesn't work

Hi, everybody! I have a new Arduino MEGA-2560 R3. It actually works great, but when I try to restart it by pushing reset button then nothing happens. What can be reason of the problem? I'm sorry for my english. It's not my native language.

RESET starts the program over. It does not erase it.

Well. I know that. But in my case when I push the button it doesn't start the aplication over. I have another arduino and there is no problems with reset button. I tested both with a multimeter. I connected GND probe to the GND contact on the arduino and plus probe to the reset one respectively. On the broken one I have no connection between the contacts when I push the reset button. Another one gets connection. So I guess it's continuity issue. Is button broken? How can I fix it?

Sloven:
On the broken one I have no connection between the contacts when I push the reset button

You found the problem.

Sloven:
Is button broken? How can I fix it?

Yes.

Either the button needs to be replaced, the button isn't soldered correctly, or there is a bad trace on the PCB.