c610 keyboard problem

Greetings folks,

 

I'm sorry if this problem have been posting before.

 

I have c610, everythings working properly but three days ago the keyboard seems have a problem.

After I use for about 1 hour, the B,N,space,down-arrow and left-arrow key doesn't response when I press it. I turning off the unit and I remove the battery and dvd module. After 10 minutes I setup those modules as in the user guide to the unit. But the problem not solved.

 

Can anyone help me to solved this problem? If I have to buy a new keyboard, where I can find it?

 

Thank you very much for your help.