keyboard wont works

hello

i have a keyboard k10a the one for venue 11pro . I use it for a year maybe. I brought it to the class to enter some grades for the students. then it stop working . The desk in the classroom is made of metal and the keyboard reacted to the metal by sticking on the desk . Well that the only strange thing that did happens beside that everything is in good condition and clean yesterday the keyboard worked for 2 minutes then stop. Now it just dont work. Anyone got some hint what might be the cause of that ?