Karbonn K595 phone 0 button not working Please tell the solution ?

Hello there, there are two things that you can do just to make sure that your key board can work properly.
1, open the case of your phone and clean up the circuit board of your key board. use a cotton with small amount of alcohol. it might have dust.
2. Reset factory setting. and please to make sure the you back up all your data, especially your phonebook.